Gingival swellings are one of the most frequently encountered lesions in the oral cavity 1. Many different conditions can present as swellings, which in some cases can make diagnosis difficult. These can range from the benign un-concerning fibro-epithelial polyps to potentially life threatening malignant lesions such as squamous cell carcinomas.

Peripheral odontogenic tumours are a group of benign rare neoplasms that occur in the mouth 2. Peripheral odontogenic fibroma is the most common type of peripheral odontogenic tumour 3,4 and presents as a benign, slow-growing, exophytic growth of soft tissue usually involving the gingiva. 

We present a case of a peripheral odontogenic fibroma mimicking common gingival swellings. The article aims to discuss a systematic approach to managing this case as well as highlighting other possible differential diagnoses. Table 1 provides an overview of swellings affecting the oral mucosa that may aid diagnosis.

Clinical case

A 62-year-old woman presented with a rapid increase in size of a long-standing swelling (Fig 1) affecting the lower left alveolus, which had been present for approximately six months. There was no associated pain or paraesthesia. Medically she had a diagnosis of atrial fibrillation, valvular heart disease and vertigo, which were managed appropriately. This included warfarin for her atrial fibrillation.

She was an ex-smoker of approximately 15 years and had occasional alcohol.

Extra oral examination revealed asymmetry of the left mandible. There was no lymphadenopathy. Intraorally the patient was partially dentate, had poor oral hygiene and clinical and radiological evidence of periodontal disease (Fig 2).

A large 2-3cm swelling was noted involving the lower left alveolus in the premolar region. Both the lower left first and second premolar were grade II mobile. The swelling was firm to palpate, fixed and with normal overlying mucosa.

Differential diagnosis

There are many causes of intraoral swellings and use of a surgical sieve approach provides a structured list of aetiological groups for systematically identifying potential causes of a presentation. These have been summarised in Table 1.

Management and outcome

Due to the sudden increase in the size of the swelling, urgent mapping biopsies of the lesion were taken. This confirmed an initial diagnosis of fibro-epithelial hyperplasia with no evidence of malignancy.

The patient was referred to the oral surgery department for removal of the residual swelling and the periodontal involved lower left premolar teeth. This was undertaken in the day procedure unit under local anaesthesia. Prior to undertaking surgery a pre-operative INR (2.12) test was carried out. The swelling and lower left premolar teeth were successfully removed under local anaesthetic. Haemostasis was achieved with cautery and the surgical site was dressed with both BIP (bismuth subnitrate, iodoform and paraffin paste impregnated gauze) packing and a suck-down vacuum splint for the first 24 to 48 hours.

At review one month post-surgery, the excision site was healing satisfactorily (See Fig 3). The final histopathology confirmed a diagnosis of a peripheral odontogenic fibroma. The patient will be reviewed on a three to six-month basis to monitor for recurrence. Further surgery may be required in the future.

 

Discussion

Peripheral odontogenic fibroma is the most common peripheral odontogenic tumour followed by the ameloblastoma and calcifying odontogenic tumour 3, 4. The most common location is the attached gingiva, usually in the molar/premolar area with even distribution between the jaws 5.

Peripheral odontogenic fibroma is an uncommon, benign, focal unencapsulated exophytic gingival mass, composed of fibrous connective tissue derived from mesenchymal origin  6. It may be pedunculated or sessile, red or pink, usually with a smooth surface and in some cases the overlying mucosa may be ulcerated. The lesion is usually firm to palpation, non-tender and could be mistaken for other more common exophytic gingival lesions, such as fibrous hyperplasia, pyogenic granuloma, or peripheral giant cell granuloma.

In the case above, the patient had been referred with a suspected oral cancer due to the rapid increase in size of a pre-existing swelling. During examination and periodontal probing, poor oral hygiene and periodontal disease could be justified for the possible cause of mobility of the premolars. An orthopantomogram radiograph did confirm bone loss consistent with periodontal disease. However, there was no periapical or bony pathology suggestive of a possible cystic, giant cell or aggressive lesion.

Due to the history of a rapid increase in swelling urgent mapping incisional biopsies were undertaken to give a better histological representation of the swelling. On the basis of this malignancy was excluded. A planned excision was arranged due to the size of the swelling and the patient’s complex medical history.

Normal Anatomy
  • Pterygoid hamulus
  • Parotid Papilla
  • Lingual tonsil
Developmental
  • Unerupted teeth
  • Odontogenic cysts
  • Eruption Cysts
  • Developmental cysts
  • Haemangioma
  • Lymphangioma
  • Mandibular, palatal tori
  • Hereditary gingival fibromatosis
  • Lingual thyroid
Inflammatory
  • Abscess (Periapical/periodontal)
  • Cellulitis
  • Pyogenic granuloma
  • Cysts
  • Sialadenitis
  • Chronic granulomatous disorders
    • Orofacial granulomatosis
    • Crohn’s disease
    • Sarcoidosis
Traumatic
  • Fibro-epithelial polyp
  • Haematoma
  • Denture induced hyperplasia
  • Mucocele
  • Surgical emphysema
Neoplasms
  • Benign
    • Fibroma
    • Peripheral giant cell granuloma
    • Central giant cell granuloma
    • Neurofibroma
    • Odontogenic Tumour –eg Peripheral odontogenic fibroma, Ameloblastoma
    • Minor salivary gland tumours
  • Malignant
    • Squamous cell carcinoma
    • Lymphoma
    • Leukaemia
    • Kaposi sarcoma
    • Myeloma
    • Salivary gland neoplasms
    • Others
Fibro-osseous
  • Cherubism
  • Fibrous Dysplasia
  • Paget’s disease
Hormonal
  • Pregnancy epulis/gingivitis
  • Oral contraceptive pill gingivitis
Metabolic
  • Amyloidosis
Drugs
  • Anticonvulsants – e.g. Phenytoin
  • Immunosuppressants – e.g. Cyclosporine
  • Calcium channel blockers – e.g. Nifidepine
Allergies
  • Angioedema
Viral
  • HPV – papilloma, verruca vulgularis, condyloma acuminatum

Table 1: Main conditions which may present as swellings or lumps in the mouth

 

Conclusion

An open mind should always be advised when managing many oral medicine/surgery cases. Many gingival lumps and swellings have similar clinical presentations and may mimic that of something more sinister. The oral cavity is a dynamic environment. This, alongside ever more complex medical histories, presents the general dental practitioner with a puzzle of information.

Despite a myriad of aetiologies, gingival swellings and lumps can often be diagnosed by a careful history. Simple factors such as presence of local irritants such as calculus could be a primary cause. By carrying out routine full head, neck and intraoral examinations and managing plaque control potential development of lesions
may be prevented.

Should further management such as biopsy, biochemistry or histological examination be required, it is important that the clinician makes an appropriate referral, providing all the essential information to enable effective, efficient and safe management of the patient.

About the author

Colm Hicks, BcHD, MFDS RCSEd; Amanda Willis, BDS, BMedSci (Hons), MMedSci PHD, MJDF RCSEng, PGCE, FDS (OM) RCPS(Glasg); John Marley, BSc BDS, PhD, FDS (OS)RCS Eng, FFDRCSI.

The authors would like to acknowledge Dr Seamus Napier, consultant oral pathology for carrying out the histopathology for this case.

References

1. Kannan S, Thapasum A, Suresh N, Muthusamy S, Chandrasekaran B. Localised Gingival Overgrowth – Differential Diagnosis for Dental Practitioners.  Dental Update 2014; 41: 698–706.

2. Manor Y, Mardinger O, Katz J, Taicher S, Hirshberg A. Peripheral odontogenic tumours – differential diagnosis in gingival lesions. International Journal Oral Maxillofacial Surgery. 2004; 33: 268–273.

3. Ide F, Obara K, Mishima K, et al. Peripheral odontogenic tumor: A clinicopathologic study of 30 cases. General features and hamartomatous lesions. Journal Oral Pathology Medicine 2005; 34:552.

4. Buchner A, Merrell PW, Carpenter WM. Relative frequency of peripheral odontogenic tumors: A study of 45 new cases and comparison with studies from the literature. Journal Oral Pathology Medicine 2006; 35:385.

5. Kenny JN, Kaugars GE, Abbey LM. Comparison between the peripheral ossifying fibroma and peripheral odontogenic fibroma. Journal of Oral and Maxillofacial Surgery 1989; 47(4): 378-382.

6. Savage N W, Daly C G. Gingival enlargements and localised gingival overgrowths. Australian Dental Journal 2010; 55: 55-60.

7. Felix H D, Luker J, Scully C Prof. Oral Medicine:11. Lumps and Swellings: Mouth. Dental Update 2013; 40: 683 – 687.

8. Saravana GHL. Oral pyogenic granuloma: a review of 137 cases. British Journal of Maxillofacial surgery 2009; 47:318 -319.

9. Motamedi MH, Eshghyar N, Jafari SM, et al. Peripheral and giant cell granulomas of the jaws: a demographic study. Oral Surgery Oral Medicine Oral Pathology Oral Radiology Endodontolgy 2007; 103: 39-43.

10. Walsh T, Liu JLY, Brocklehurst P, Glenny AM, Lingen M, Kerr AR, Ogden G, Warnakulasuriya S, Scully C. Clinical assessment to screen for the detection
of oral cavity cancer and potentially malignant disorders in apparently healthy adults. Cochrane Database of Systematic Reviews 2013, Issue 11.

11. Smittenaar CR, Petersen KA, Stewart K, Moitt N. Cancer incidence and mortality projections in the UK until 2035. Br J Cancer. 2016 Oct 25; 115(9): 1147–1155.

12. National Institute for health care and excellence. Suspected cancer: recognition and referral – NICE Guideline NG12. 2015 (last updated July 2017) available online www.nice.org.uk/guidance/ng12/resources/suspected-cancer-recognition-and-referral-pdf-1837268071621 [last accessed January 18, 2018]
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13. Healthcare improvement Scotland. Scottish referral guidelines for suspected cancer 2013 (updated in August 2014) available online www.healthcareimprovementscotland.org/our_work/cancer_care_ improvement/programme_resources/scottish_referral_guidelines.aspx [last accessed 18 January, 2018].

14. Agrawal AA: Gingival enlargements. Differential diagnosis and review of literature. World Journal of Clinical Cases 2015; 16: 3(9): 779-788.

15. Hallimon WW, Rossmann JA. The role of drugs in the pathogenesis of gingival overgrowth. A collective review of current concepts. Periodontology 2000; 21: 176-196.

16. Sculley C, Porter S. Orofacial Disease. Update for the Dental Clinical Team: 5. Lumps and Swellings. Dental Update 1999; 26: 214-217.

Short and extra-short implants are a powerful tool in oral implantology these days 1. The use of these implants facilitates the rehabilitation of very resorbed edentulous ridges with a simple approach. The principal problem with the short implants, and most commonly with extra-short implants, is the crown-to-implant (CI) ratio. The high space to rehabilitate and the longitude of these implants creates an unfavourable prosthesis on the basis of the CI ratio.

The CI ratio is a term imported by the general odontology, and the use of these parameters in implants is used in a similar way. The use of the concept in general odontology translates to the use of implant prosthesis, and while they have similar points they also have some big differences. The most important difference is the biomechanical behaviour of the implant-prosthesis conjunct and the way to convey the stress to the crestal bone. The absence of periodontal ligament and the anchylotic union between the bone and the implant may generate a great force in the crestal bone and we can think how this increase produces a major bone resorption.

In relation to these differences between the length of the restorations and implants it would appear to indicate a bad biomechanical behaviour of the assembly with impact on the marginal bone loss and increasing the rate of failure. To analyse the studies published in relation to this topic, they do not show how a greater bone loss in high crown-implant ratios and ratios higher than two has been considered a safe and predictable therapeutic option 25.

The aim of this study was to evaluate the effect of the CI ratio on the marginal bone stability around extra-short implants supporting a fixed-partial prosthesis in posterior mandible. The secondary outcome was to the
implant survival.

Material and methods

This manuscript was written according to the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) guidelines 6. All described data and treatments were obtained from a single dental clinic in Vitoria, Spain. Patients’ records were retrospectively reviewed to identify patients that fulfilled the following inclusion criteria:

Aged over 18 years old

Placement of extra-short (length ≤ 6.5 mm) implants before December, 2010

Placed in posterior mandible.

The principal outcome was the marginal bone loss and the secondary outcome was the implant survival rate.

Patients or implants that did not meet any of these criteria were excluded from the study. Prior to surgery, and in order to make a proper treatment plan, all patients underwent standard diagnostic protocol consisting of reviewing the medical and dental history, diagnostic casts, and radiographic evaluation.

To assess the principal and secondary outcomes, implants were followed clinically and radiographically to identify the crestal bone loss and implant failure (failure to achieve osseointegration or loss of acquired osseointegration).

The measurement of the marginal bone loss was performed on the most recent radiograph. To do that, known implant length was used to calibrate the linear measurements on the radiograph. Then, the distance between the uppermost point of the implant platform and the most coronal bone-implant contact was measured mesial and distal to the implant by computer software (Sidexis, Sirona, USA). The bone level recorded just after the placement of the provisional prosthesis served as a reference for the measurement of the marginal bone loss. The bone loss was measured mesially and distally to the implant. Finally, a mean of the two measurements were reported due to the absence of statistically
significant differences.

The crown-implant ratio was determined by two measurements: the crown was measured from the tip of the highest cusp to the platform of the implant, along a perpendicular line. The implant was then measured at the centre, from the platform to the end of the apex (Figure 1).

In all patients, the same surgical protocol was followed. Before surgery, patients underwent a routine dental scaling to start the implant treatment with adequate periodontal health. Radiographic evaluation was also performed to establish the treatment plan. All patients received prophylactic antibiotic medication before and after surgery. An infiltrative anaesthesia was applied and incisions were made to elevate a full-
thickness flap.

Implant sites were prepared using a low-speed drilling procedure (125 rpm) without irrigation 7,8. Before installation, implants were carefully embedded in liquid Plasma Rich in Growth Factors (PRGF) prepared from patient’s blood according to a protocol developed by the manufacturer (PRGF-Endoret, Biotechnology Institute BTI, Vitoria, Spain) to bioactivate the implant surface.

For placing the dental implant, the surgical motor was set at 25 Ncm and the implants were finally seated manually by a calibrated torque wrench. The final insertion torque was annotated in the patient’s record.

A prosthodontist performed the prosthetic rehabilitation of the patients. Impression copings were placed and an impression was made with polyether impression material (Impregum Penta; 3M ESPE) and the open-tray technique at three months after implant insertion.

The follow-up visits were scheduled for a series of periodic evaluations, consisting normally of visits at one week after intervention, at one month, at three months, at six months, and from this moment ahead, once a year.

 

 

Statistical analysis

Data collection and analysis was performed by two independent examiners. The patient was the statistical unit for the statistical description of demographic data, social habits and medical history. The implant served as the statistical unit for the descriptions of implant length, diameter, location, insertion torque, marginal bone loss and survival of the implants. Absolute and relative frequency distributions were calculated for qualitative variables and mean values and standard deviations for quantitative variables. The Shapiro-Wilk test was selected to check the normal distribution of the data.

The cumulative survival rate of implants were analysed using a life-table analysis (Actuarial method). SPSS v15.0 for Windows statistical software package (SPSS Inc., Chicago, IL, USA) was used for statistical analysis.

Results

In this study, 32 patients participated with 46 implants with a Crown-implant ratio higher than 1. The patients’ mean age was 68 ± six years (range: 55 to 74 years) at the time of surgery and 78.3 per cent of the patients were females.

Three patients were smokers (4.8 per cent), and none of them referred alcohol habits. One of the patients was diabetic (1.6 per cent), seven patients had previous periodontal disease (11.1 per cent), one patient had previous radiation (1.6 per cent).

The diameter, length and position of the implants included in the study are shown in Figure two. The mean of the follow-up was 23 ± eight months (range 14 to 43). The mean crown-implant ratio was 2.4 ± 0.47 (range 1.50-3.64).

Regarding the type of prosthesis, all patients were rehabilitated using fixed-partial prosthesis. In total, 67.4 per cent of the restorations were screw-retained prosthesis and the rest were cemented.

The measurement of marginal bone loss (MBL) was performed at 12 and 24 months of loading. The mean of mesial bone loss was 1.04 ±0.70 mm and the mean distal bone loss was 0.94 ± 0.71 mm. There was no statistically significant difference between the MBL measurements at different follow-up times (p > .05), indicating that bone level around implants under functional loading was stable over time. No significant influence was found between the CI ratio and MBL, even considering separately CI < 2 and CI ≥ 2.

The overall survival rates of short implants and prosthesis were 100 per cent for the implant and patient-based analysis, respectively, at the end of the follow-up time. In figures three to 10 we show a case of the patients included in the study.

Discussion

The prosthetic rehabilitations in which short implants are involved often lead to imbalances between the lengths of the crowns and the implants. It has been suggested that disproportionate prosthetic restorations could induce poor biomechanical behaviour with a potential impact on MBL and reduced implaent survival rate 9. In this study, no associations between CI ratio of implant-supported prostheses in extra-short implants and MBL were found. Previous studies in which short implants were used have evaluated the influence of CI ratio on marginal bone loss (MBL) 1012. In general, most of these studies concluded that no relation may be established between an unfavourable CI ratio and MBL, independently of the type of prosthetic rehabilitation 1012.

All the implants included in this study were splinted restorations. Short and extra-short implants have shown better biomechanical behaviour when the prosthesis have been splinted. An additional rationale for splinting implant crowns together is to favourably distribute the non-axial loads, minimising their transfer to the restoration and supporting bone, and increasing the total load area 13,14. Splinting the crowns reduced the peri-implant bone stress under horizontal load in a finite element analysis model especially recommended for implants surrounded by poor-quality bone 13,15.

When placing extra-short implants, it is necessary to carry out adequate planning and the splinting implants are a correct protocol in these cases 16,17.

Conclusions

Within the limitations of this study, the results show that an increased crown-to-implant ratio in extra-short implants has no significant influence on crestal bone loss and implant survival. The limitations of this study include its retrospective design, the small sample size and short follow-up time. Further studies with more extra-short implants followed for a longer period of time are necessary to establish sound conclusions about the effect of increased crown-to-implant ratio on implant survival.

 

About the author

Eduardo Anitua DDS, MD, PhD graduated with a degree in medicine and surgery from the University of Salamanca and gained his PhD in medicine from the University of Valencia. He holds a specialism in stomatology from the University of the Basque Country (UPV/EHU) and a diploma in prostheses and occlusion from the Pankey Institute (Florida, USA). He is a visiting professor at more than 20 universities in the USA (Harvard, Boston, Tufts, Pennsylvania, New Orleans), Germany (Berlin), England (Bristol), Italy (Milan, Turin), India, Mexico, Brazil, Portugal, Argentina, Colombia, Venezuela, Uruguay and Spain (Seville, Madrid, Barcelona, Murcia). Dr Anitua has published more than 200 papers in national and international journals, is the author of eight books and co-author of seven books and chapters translated into various languages. He has 37 international patents developed in regenerative therapy and oral implantology.

 

References

1. Gonçalves TM, Bortolini S, Martinolli M, Alfenas BF, Peruzzo DC, Natali A, Berzaghi A, Garcia RC. Long-term Short Implants Performance: Systematic Review and Meta-Analysis of the Essential Assessment Parameters. Braz Dent J. 2015;26:325-36.

2. Rokni S, Todescan R, Warson P, Pharoah M, Adegbembo AO, Deporter D. An assessment of crown-to-root ratios with short sintered porous-surfaced Implants supporting prostheses in partially edentulous patients. INT J ORAL MAXILLOFAC IMPLANTS 2005;20:69–76

3. Blanes RJ, Bernard JP, Blanes ZM, Belser UC. A 10-year prospective study of ITI dental implants placed in the posterior region. II: Influence of the crown-to-implant ratio and different prosthetic treatment modalities on crestal bone loss.  Clin. Oral Impl. Res. 18, 2007; 707–714

4. Schneider D, Witt L, Ha ̈mmerle CHF. Influence of the crown-to-implant length ratio on the clinical performance of implants supporting single crown restorations: a cross- sectional retrospective 5-year investigation.  Clin. Oral Impl. Res. 23, 2012;169–174.

5. Sanz M, Naert I; Working Group 2. Biomechanics/risk management (Working Group 2). Clin Oral Implants Res. 2009;20(suppl 4):107-111.

6. Von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP, et al. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 2007;370:1453-1457.

7. Anitua E, Alkhraisat MH, Pinas L, Orive G. Efficacy of biologically guided implant site preparation to obtain adequate primary implant stability. Ann Anat.

8. Anitua E, Carda C, Andia I. A novel drilling procedure and subsequent bone autograft preparation: a technical note. Int J Oral Maxillofac Implants 2007; 22: 138-145.

9. Blanes RJ, Bernard JP, Blanes ZM, Belser UC. A 10-year prospective study of ITI dental implants placed in the pos- terior region. II: influence of the crown-to-implant ratio and different prosthetic treatment modalities on crestal bone loss. Clin Oral Implants Res 2007; 18:707–714.

10. Rokni S, Todescan R, Watson P, Pharoah M, Adegbembo AO, Deporter D. An assessment of crown-to- root ratios with short sintered porous-surfaced implants supporting prostheses in partially edentulous patients. Int J Oral Maxillofac Implants 2005; 20:69–76.

11. Tawil G, Aboujaoude N, Younan R. Influence of prosthetic parameters on the survival and complication rates of short implants. Int J Oral Maxillofac Implants 2006; 21:275–282.

12. Birdi H, Schulte J, Kovacs A, Weed M, Chuang SK. Crown- to-implant ratios of short-length implants. J Oral Implantol 2010; 36:425–433.

13. Nissan J, Ghelfan O, Gross O, Priel I, Gross M, Chaushu G. The effect of crown/implant ratio and crown height space on stress distribution in unsplinted implant supporting restorations. J Oral Maxillofac Surg 69:1934-1939, 2011

14. Nissan J, Ghelfan O, Gross O, Priel I, Gross M, Chaushu G. The effect of splinting implant-supported restorations on stress distribution of different crown-implant ratios and crown height spaces. J Oral Maxillofac Surg 69:2990-2994, 2011

15. Grossmann Y, Finger IM, and Block MS. Indications for Splinting Implant Restorations. J Oral Maxillofac Surg 2005; 63:1642-1652.

16. Anitua E, Piñas L, Orive G. Retrospective study of short and extra-short implants placed in posterior regions: influence of crown-to-implant ratio on marginal bone loss. Clin Implant Dent Relat Res. 2015;17:102-10.

17. Anitua E, Alkhraist MH, Piñas L, Begoña L, Orive G. Implant survival and crestal bone loss around extra-short implants supporting a fixed denture: the effect of crown height space, crown-to-implant ratio, and offset placement of the prosthesis. Int J Oral Maxillofac Implants. 2014;29:682-9.

A narrow diameter implant is an implant with a diameter less than 3.75mm and is clinically indicated to replace maxillary lateral incisors and mandibular incisors1. The availability of interdental space less than 6mm and/or residual bone width less than 5mm are also indicative for the use of narrow diameter implant (NDIs)1.

NDIs have significantly reduced the need for bone grafting among completely edentulous patients2. This would permit the avoidance of complications associated with alveolar bone augmentation such as prolonged healing time, additional costs and increased surgical morbidity2, 4.  In a recent study, Pommer et al. conclude that, while little evidence on patients’ preferences towards minimally invasive treatment alternatives as opposed to bone augmentation surgery could be identified from within-study comparison, patient satisfaction with graftless solutions for implant rehabilitation of completely edentulous jaws is generally high5.

Long-term survival of the narrow implants in posterior areas of the maxilla and mandible is not well documented. A recent study with this type of implants in areas with combination of split crest technique seems to indicate a successful implant survival rate (97 per cent)6.

Ortega-Oller et al. in a meta-analysis have shown that narrower implants (<3.3mm) have significantly higher failure rates than wider implants (≥ 3.3mm)7. This could   be influenced by other variables such as type of prosthesis, implant surface, and timing of prosthetic loading7. Klein et al. in a recent systematic review reported that the survival rate of implants with a diameter < 3mm were higher than 90 per cent with a follow-up time of between one and three years8. For implants with a diameter between 3.0 and 3.25mm the survival rate was higher than 93.8 per cent (follow-up of one to five years). Those implants with a diameter ≥ 3.3mm had a survival rate of 88.9 per cent to
100 per cent with a follow-up time of one to 12 years. The most common causes of implant failure have been lack/loss of osseointegration and infection1, 9, 10.

From the above, NDIs have a comparable success rate as wider implants not only in the anterior region but also in the posterior regions.

For that, this study was conducted to analyse the long-term outcomes of using 2.5mm NDIs as definitive implant for rehabilitation of missing teeth in posterior areas.

Material and methods
This article was written following the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) guidelines11 and included patients treated at a single dental clinic in Vitoria, Spain. Patients included in the study fulfilled the following criteria:

  • Both genders and over 18 years old
  • Patients with totally or partially edentulous jaws who were treated by one or more 2.5mm narrow-diameter implants due to insufficient bone ridge thickness (< 5mm) and/or reduced mesio-distal space (< 6mm)
  • Implants inserted before July 2005
  • Implants inserted in posterior areas (premolar
    and molar)
  • A retrospective cohort study design was used.

Data collection
Patient records were analysed to derive demographic data (gender, age), social habits (smoking, alcohol intake), relevant medical conditions, and history of periodontal disease. Then a database was conformed with implants data (length, diameter, and insertion torque) and localisation.

For implant survival assessment, implant failure was considered any implant lost due to biological (failure to achieve osseointegration or loss of acquired osseointegration) or biomechanical causes.

For Marginal Bone Loss (MBL) quantifications, marginal bone levels were measured on the periapical radiograph made just after the surgery and the last available periapical radiograph. The radiographs were obtained using paralleling technique with a film holder (Superbite, KerrHawe, Barcelona, Spain).

Measurements of MBL on the periapical radiographs were performed by computer software (Digora, Soredex, USA), a calibration of the periapical radiograph by a known length (implant length) was performed. Once the radiograph was calibrated to a 1:1 measure, eliminating the possible presence of magnification, measurements were made mesially and distally to the implants, calculating the distance between the uppermost point of the implant platform and the most coronal contact between the bone and the implant. The bone level recorded just after the surgical insertion of the implant was the basal value to compare with subsequent measurements over time.

For prostheses survival assessment, prostheses failure was considered as any complication that led to prosthesis removal (screw loosening/ fracture abutment/ implant fracture/ceramic chipping and prosthesis fracture).

Surgical procedures
All surgeries were made by two experienced surgeons. Before surgery, patients underwent a routine dental scaling to start the implant treatment with an adequate periodontal health. Radiographic evaluation was also performed to establish the treatment plan.

Patients received 2g of amoxicillin (600mg of clindamycin for allergic patients) 60 minutes before surgery and 1g of acetaminophen, 30 minutes preoperatively. Local anesthesia was achieved by the administration of articaine hydrochloride with epinephrine (1:100,000).

Implant sites were prepared using a low-speed drilling procedure (125 rpm) without irrigation12,13. Before installation, implants were carefully embedded in liquid Plasma Rich in Growth Factors prepared from patient’s blood according to a protocol developed by the manufacturer (PRGF-Endoret, Biotechnology Institute BTI, Vitoria, Spain) to bioactivate the implant surface.

Rehabilitations were made by the restorative dentist. In general, healing was allowed for a minimum of three months, after which the healing abutments were fixed. Shortly thereafter, the suprastructure was placed. Immediate loading protocol was applied in four patients (eight NDIs). Implants were loaded immediately only if they achieved an insertion torque of at least 45Ncm.

Post-surgical clinical assessments
Once the surgical phase was conducted, patients were scheduled for a series of periodic evaluations, consisting normally of: one evaluation five to 10 days after intervention, at one month, at three months, at six months, and from this moment ahead, once a year. The post-implant assessment included, at each follow-up visit, different clinical assessments to verify the status of the implant (gingival health, prosthesis mobility, pain, infection, alveolar ridge resorption and any complications).

Moreover, periodic panoramic and periapical radiographs were carried out to verify the implant clinical status in the follow-up period.

Statistical analysis
Data collection and analysis was performed by two independent examiners (other than restorative dentist and surgeon). The patient was the statistical unit for the statistical description of demographic data, social habits, medical history and history of periodontal disease. Mean values, standard deviations, and ranges were calculated for age, while relative frequency was calculated for the remaining patient-related variables.

The implant served as the statistical unit for the descriptions of implant length, diameter, location, insertion torque, marginal bone loss, survival an prosthetic parameters. Absolute and relative frequency distributions were calculated for qualitative variables and mean values and standard deviations for quantitative variables. The survival of implants and prostheses were evaluated with Kaplan-Meier method. SPSS v15.0 for Windows statistical software package (SPSS Inc., Chicago, IL, USA) was used for statistical analysis.

Results
In this study, a total of 25, 2.5mm narrow-diameter implants placed in 15 patients were included and evaluated. Eighty per cent of the patients were female and the mean age at surgery was 53 ± 9.2 years. Four patients were smokers (20 per cent). The length of the implants ranged between 11.5mm and 15mm. The implants mean follow-up time since insertion was 6.5 ± 3.9 years (range 0 to 9.5 years).

The mean follow-up time of the prostheses was 5.67 years (SD = 36.06). Figure 1 shows the anatomical locations of implants. Fifteen implants (60 per cent) were placed in the maxilla, whereas 10 were placed in the mandible (40  per cent).

Delayed implant loading was performed for 17 implants (68 per cent). The implant loading was performed after eight ± four months since insertion (range: five to 21 months). Five implants (32 per cent) were submitted to immediate loading protocol.

Regarding the type of the prosthesis, 12 implants (48 per cent) were involved in a fixed partial bridges, whereas 12 implants were involved in four screwed complete prostheses (48 per cent), and the one remaining implant was restored with a cemented single crown (4 per cent).

For the assessment of long-term MBL, only those cases where the last available periapical radiograph was performed after at least seven years of insertion were taken into account. Twenty one implants (mean follow-up time of 8.9 ± 0.5 years) that satisfied this requirement were analysed. The mean MBL was 0.64mm at the mesial side (SD = 0.64, range between 0 and 1.95mm), and 0.66mm (SD = 0.62, range between 0.00 and 2.19mm) at the distal side.

The survival rate was 100 per cent for implants. Two prostheses failed during the observation period. The prosthetic complications were porcelain fracture in another patient and connector fracture in other patient. This resulted in prostheses survival rate of 92.0 per cent (Figure 2).

Figure 3 illustrates the clinical situation of a patient involved in the study before and after 10 years of treatment with narrow diameter implants.

Discussion
Eighty seven per cent of the implants were followed for more than three years and 60 per cent for more than seven years. During the follow-up period, no implants have failed resulting in a survival rate of 100 per cent. In a review, Renouard and Nisand reported an implant survival rate higher than 90 per cent for 3mm and 3.3mm implants14. Sohrabi et al. have similarly concluded that the survival rate of NDIs is generally higher than 90 per cent and that the failure rate appeared to be higher in small-diameter implants less than 13mm in length15. Klein et al. have reported that available studies on dental implants <2.5mm in diameter reported a survival rates between 90 and 100 per cent8.

In a recent meta-analysis by Ortega-Oller et al. the majority of the analysed studies (implants less than 3.3mm in diameter) have also reported a survival/success rate higher than 90 per cent7. However, the results of the meta-analysis have shown higher failure rates for implants with a diameter <3.3mm when compared to implants with a diameter ≥3.3mm. The authors have related this outcome with the fact that NDIs are usually placed in complicated clinical scenario and they have higher possibility of fracture7. Interestingly, according to that review, the failure rate will be more probable if the implants are loaded in a period less than three months since insertion and/or have a smooth implant surface7.

In the present study, the survival rate of NDIs was comparable to standard implants. The high survival rate of the NDIs could be related to the fact that the implants placed in this study had a roughened surface. Furthermore, 26 implants were loaded after eight months (± four months) since implant insertion and no one of these had failed.

Abutment screw loosening is one of the most common prosthetic complications that was being reported by clinical studies on NDIs8. This complication could be the result of different factors such as component misfit, inadequate tightening, settling of the screw, inadequate screw design and excessive loading16. The absence of screw loosening in this long-term follow-up could related to the fact that all implants (except one) were splinted by a fixed prostheses.

Splinting multiple implants has been reported to minimise the lateral force on the prosthesis, to enhance force distribution, and to reduce the stress on the implants17,18. Thus, splinting of 2.5-diameter implants would protect the implants from excessive loading and prevent implant/abutment screw fracture.

In this study, all the implants were inserted in posterior areas. In this type of rehabilitation, the risk of ‘fatigue’ fractures of the implants exists19,20. Freitas-Junior et al. have concluded in a biomechanical study that a single NDI is less reliable than a standard implant or two NDIs to support single crown in the molar region21. In our study, the survival of implants were 100 per cent and there were no biomechanical complications with the implants.

The measurement of marginal bone loss around the NDIs had a mean value below 1mm for the implants with follow-up time more than seven years since insertion. This would indicate the absence of excessive mechanical loading on the 2.5mm diameter implants. Similar results have been reported by Wang et al.22.

This study suffers from the limitation of a retrospective study design and the small sample size. The retrospective study provides evidence of lesser strength than the evidence derived from prospective or randomised clinical trial. There is also a dependency on the availability and accuracy of medical/dental records.

Conclusions
The use of narrow diameter implants in narrow alveolar ridges in posterior areas could constitute a minimally invasive alternative to bone augmentation surgery. NDIs of 2.5mm have resulted in a high survival rate in a long-term follow-up. This outcome could be related to the fact that these implants have all been splinted to other implants by a fixed prosthesis. This prosthetic configuration may have minimised the probability of implant and prosthesis failure.


References
1. Andersen E, Saxegaard E, Knutsen BM, Haanaes HR. A prospective clinical study evaluating the safety and effectiveness of narrow-diameter threaded implants in the anterior region of the maxilla. Int J Oral Maxillofac Implants 2001; 16: 217-224.

2. Papadimitriou DE, Friedland B, Gannam C, Salari S, Gallucci GO. Narrow-Diameter versus Standard-Diameter Implants and their Effect on the Need for Guided Bone Regeneration: A Virtual Three-Dimensional Study. Clin Implant Dent Relat Res.

3. Anitua E, Alkhraisat MH, Orive G. Novel technique for the treatment of the severely atrophied posterior mandible. Int J Oral Maxillofac Implants 2013; 28: 1338-1346.

4. Esposito M, Cannizzaro G, Soardi E, Pellegrino G, Pistilli R, Felice P. A 3-year post-loading report of a randomised controlled trial on the rehabilitation of posterior atrophic mandibles: short implants or longer implants in vertically augmented bone? Eur J Oral Implantol 2011; 4: 301-311.

5. Pommer B, Mailath-Pokorny G, Haas R, Busenlechner D, Furhauser R, Watzek G. Patients’ preferences towards minimally invasive treatment alternatives for implant rehabilitation of edentulous jaws. Eur J Oral Implantol 2014; 7 Suppl 2: S91-109.

6. Garcez-Filho J, Tolentino L, Sukekava F, Seabra M, Cesar-Neto JB, Araújo MG. Long-term outcomes from implants installed by using split-crest technique in posterior maxillae: 10 years of follow-up. Clin Oral Implants Res. 2015 Mar;26(3):326-31.

7. Ortega-Oller I, Suarez F, Galindo-Moreno P, Torrecillas-Martinez L, Monje A, Catena A, Wang HL. The influence of implant diameter on its survival: a meta-analysis based on prospective clinical trials. J Periodontol 2014; 85: 569-580.

8. Klein MO, Schiegnitz E, Al-Nawas B. Systematic review on success of narrow-diameter dental implants. Int J Oral Maxillofac Implants 2014; 29 Suppl: 43-54.

9. Polizzi G, Fabbro S, Furri M, Herrmann I, Squarzoni S. Clinical application of narrow Branemark System implants for single-tooth restorations. Int J Oral Maxillofac Implants 1999; 14: 496-503.

10. Zinsli B, Sagesser T, Mericske E, Mericske-Stern R. Clinical evaluation of small-diameter ITI implants: a prospective study. Int J Oral Maxillofac Implants 2004; 19: 92-99.

11. Von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 2007; 370: 1453-1457.

12. Anitua E, Alkhraisat MH, Pinas L, Orive G. Efficacy of biologically guided implant site preparation to obtain adequate primary implant stability. Ann Anat.

13. Anitua E, Carda C, Andia I. A novel drilling procedure and subsequent bone autograft preparation: a technical note. Int J Oral Maxillofac Implants 2007; 22: 138-145.

14. Renouard F, Nisand D. Impact of implant length and diameter on survival rates. Clin Oral Implants Res 2006; 17 Suppl 2: 35-51.

15. Sohrabi K, Mushantat A, Esfandiari S, Feine J. How successful are small-diameter implants? A literature review. Clin Oral Implants Res 2012; 23: 515-525.

16. Patil PG. A technique for repairing a loosening abutment screw for a cement-retained implant prosthesis. J Prosthodont 2011; 20: 652-655.

17. Anitua E, Tapia R, Luzuriaga F, Orive G. Influence of implant length, diameter, and geometry on stress distribution: a finite element analysis. Int J Periodontics Restorative Dent 2010; 30: 89-95.

18. Pierrisnard L, Renouard F, Renault P, Barquins M. Influence of implant length and bicortical anchorage on implant stress distribution. Clin Implant Dent Relat Res 2003; 5: 254-262.

19. Chiapasco M, Casentini P, Zaniboni M, Corsi E, Anello T. Titanium-zirconium alloy narrow-diameter implants (Straumann Roxolid) for the rehabilitation of horizontally deficient edentulous ridges: prospective study on 18 consecutive patients. Clin Oral Implants Res 2012; 23: 1136-1141.

20. Davarpanah M, Martinez H, Tecucianu JF, Celletti R, Lazzara R. Small-diameter implants: indications and contraindications. J Esthet Dent 2000; 12: 186-194.

21. Freitas-Junior AC, Bonfante EA, Martins LM, Silva NR, Marotta L, Coelho PG. Effect of implant diameter on reliability and failure modes of molar crowns. Int J Prosthodont 2011; 24: 557-561.

22. Wang HL, Okayasu K, Fu JH, Hamerink HA, Layher MG, Rudek IE. The success rate of narrow body implants used for supporting immediate provisional restorations: a pilot feasibility study. Implant Dent 2012; 21: 467-473.


About the author
Eduardo Anitua DDS, MD, PhD graduated with a degree in medicine and surgery from the University of Salamanca and gained his PhD in medicine from the University of Valencia.
He holds a specialism in stomatology from the University of the Basque Country (UPV/EHU) and a diploma in prostheses and occlusion from the Pankey Institute (Florida, USA).

He is a visiting professor at more than 20 universities in the USA (Harvard, Boston, Tufts, Pennsylvania, New Orleans), Germany (Berlin), England (Bristol), Italy (Milan, Turin), India, Mexico, Brazil, Portugal, Argentina, Colombia, Venezuela, Uruguay and Spain (Seville, Madrid, Barcelona, Murcia).

Dr Anitua has published more than 200 papers in national and international journals, is the author of eight books and co-author of seven books and chapters translated into various languages. He has 37 international patents developed in regenerative therapy and oral implantology.

As a dentist working in general practice it is imperative to ensure that valid consent has been obtained for each individual patient. Following on from the judgement in the Montgomery case in March 2015, which brought the law of consent up to speed with what the GDC’s ethical and professional guidance expected registrants to do, this article looks at the responsibilities of the general dental practitioner. The importance of excellent communication is highlighted in order to provide sufficient and relevant information to the particular patient you have sitting in your dental chair.

The GDC has set out nine principles in their Standards for the Dental Team document. One of the key principles is obtaining valid consent. This document sets out the standards of conduct, performance and ethics that govern you as a dental professional. The guidance applies to all members of the dental team.

Why do we obtain consent?
For a GDP, there are ethical and moral obligations to ensure that your patient understands the treatment proposed and for consent to be valid. Consent is important because any investigation or treatment carried out without a patient’s consent or proper authority may be regarded as assault. This can lead to further investigations resulting in criminal proceedings, an action for damages, a breach in the duty of care and a finding of impaired fitness to practise by the GDC. There are cases where this is exactly what has happened.

Adults with capacity
The test for capacity and the ability of a patient to undertake decisions is set out in the Mental Capacity Act 2005 (MCA) and are supported by the code of practice established under the act, which dental professionals are expected to follow.

In the case of a patient undergoing a dental examination, consent is the expressed or implied permission of a patient to undergo this check-up, investigation and treatment. It is essential that consent is given freely and with adequate understanding of the condition to be treated, the procedures involved, other treatment options and the health implications of giving and withholding consent. It is also important to check that the patient understands the information given.

Adults without capacity
When making decisions on behalf of adults lacking capacity there are a number of points to consider. In Scotland, under the Adults with Incapacity (Scotland) Act 2000, a competent adult can nominate a welfare attorney to make decisions on their behalf should they lose capacity to make those decisions themselves. The law also provides general power to treat a patient who is unable to give consent.

The dental professional responsible for treatment must have completed a certificate of incapacity before any treatment is undertaken, other than in an emergency. Put simply, decide what constitutes a patient’s best interests by taking into account factors other than just their dental condition – treat the patient holistically. Consider consulting with others, including getting a second opinion from a colleague before starting treatment.

Consent and children under the age of 16
Children under the age of 16 can give valid consent to treatment if they are deemed to be Gillick competent. The ability for a child to give valid consent depends on their maturity and understanding. To be Gillick competent, a child must understand the proposed treatment, risks and alternatives, they must be able to retain that information and be able to weigh up the pros and cons of the treatment. The child must be able to communicate that their decision to have the treatment.

If a child is not deemed to be Gillick competent then someone with parental responsibility must provide this authority. It is important to note that emergency care should not be delayed in order to prevent serious harm. In deciding whether or not to treat, the child’s best interests must be considered. Even if a child is Gillick competent, I always encourage an open dialogue between parents and children when it comes to making decisions regarding their health.

Criteria for consent
It is fundamental that valid consent is obtained before starting any treatment. You must make sure that your patient understands the decisions they are being asked to make and that the consent is valid at each stage of the treatment or investigation. Having good communication with your patients is vital in order to obtain valid consent. The way consent is obtained must be tailored to suit the patient’s needs.

As the Standards for the Dental Team states, patients must be given: options for treatment, risks, benefits, why a treatment is necessary and appropriate, consequences and risks of the proposed treatment, prognosis and consequences of not having the treatment, whether the treatment is guaranteed and for how long. Failure to give correct or sufficient information may result in a breach in your duty of care and if proven there was a negligent failure to inform and, as a direct result the patient suffered harm, the patient may take further action.

The cost of any examination, investigation or treatment should also be explained before it starts. It is important to note that a patient who pays the bill has not necessarily consented to treatment. If a patient’s condition changes, causing a change in the proposed risks, then consent must be obtained again, any changes in cost must also be reviewed with the patient. Duress of any form, such as influence from someone else can invalidate consent.

The advice from the Dental Defence Union is to ideally have a ‘cooling off’ period in which the patient can think over their decision and can seek further advice on this if they need to do so. It is best to re-confirm consent with a patient immediately before any treatment. You should also include as much information in your notes about those discussions as possible.

Consent checklist
By developing a logical approach in your daily practice you can ensure that the consent obtained is valid. The patient should be aware of the purpose, nature, and likely effects, risks, chances of success of a proposed procedure, and of any alternatives to it. It is important to note that consent is not open ended and must be obtained again at subsequent occasions. Consent must be obtained for specific procedures, on specific occasions. When the patient is in your dental chair you need to be certain that valid, informed consent has been obtained.

The following checklist is reproduced from the Consent – Scotland publication from Dental Protection Limited (http://bit.ly/DPLconsent)

Ask yourself:

  • Is my patient capable of making a decision? Is the decision made voluntary and without coercion in terms of the balance/bias of the information given, or the timing or context of its provision?
  • Does my patient need this treatment? Remember, if it is an elective procedure then the onus upon a clinician to communicate information and warnings become much greater. The procedural steps, risks and recovery should be discussed in detail prior to the treatment appointment and the patient should be given adequate time to consider the information given.
  • What will happen in the circumstances of this particular case – what will happen if I proceed with the treatment? Is my patient fully aware of my assessment in clear terms? Can I predict the outcome accurately? If not, then what are the areas of doubt and what are the possible alternative outcomes?
  • What should a reasonable person expect to be told about proposed treatment? In this case, is there anything specifically important or relevant about my patient? (If in doubt then you are not ready to proceed with the proposed treatment).
  • Does information for my patient need to be provided in writing or has my patient requested a wish to have written information? Remember, if you are relying on providing information through marketing material, it is important to make sure that it is presented in a balanced and unbiased manner.
  • Accurate and contemporaneous records are imperative. Do my records accurately reflect the conversations with my patient? Will these notes allow me to show what information was given to my patient? On what terms and what was said at what time?
  • Does my patient understand what treatment they have agreed to and why? Have they been given the opportunity and adequate time to consider the treatment and its implications, and time to raise concerns and/or have their questions answered?
  • Does my patient understand the costs involved? As well as the potential future costs in terms of complications?
  • Does my patient need time to consider the treatment options proposed or is my patient wishing to discuss proposals with someone else?
  • If I am inexperienced at carrying out the procedure in question, does my patient know that? Is my patient aware that their prospects of a successful outcome if they choose to have the procedure carried out by a specialist or a more experience colleague? Is the technique being used relatively new/untried and does my patient understand this?

References
1. General Dental Council. Standards for the Dental Team. Guidance of obtaining valid consent. GDC; 30 September 2013. Available at https://www.gdc-uk.org/api/files/NEW%20Standards%20for%20the%20Dental%20Team.pdf [Accessed on 21/10/17]

2. Dental Protection. Consent – Scotland. Dental Protection Limited. Available at http://bit.ly/DPLconsent [Accessed on 22/10/17]

3. ISD Scotland. Dental Statistics – NHS Registration and participation. A National Statistics Publication for Scotland; 2017. Available at: www.isdscotland.org/Health-Topics/Dental-Care/Publications/2017-01-24/2017-01-24-Dental-Report.pdf?49161928893 Accessed 30/10/2017

4. Dental Defense Union Guide – Consent guide [Accessed 25/10/17]

5. Harris J, Sidebotham P, Welbury R. Child protection and the dental team. An introduction to safeguarding children in dental practice. Sheffield: Committee of Postgraduate Dental Deans and Directors, 2006. Available at: bda.org/childprotection [Accessed 15/10/2017]

6. Department of Health. National Institute for Clinical Excellence – Consent, procedures for which the benefits and risks are uncertain. Available at https://www.nice.org.uk/guidance/ipg56/documents/consent-procedures-for-which-the-benefits-and-risks-are-uncertain2 [Accessed 30/10/2017]


About the author
Aisha Shafi is a general dental practitioner with a special interest in cosmetic dentistry and facial aesthetics, currently working in clinics based in Glasgow, London and Portsmouth. She was a finalist for Dentist of the Year at the Scottish Dental Awards 2017 and shortlisted for ‘Best Professional’ with the Scottish Asian Business Awards.

Aisha helps run the British Smile Foundation, a group that actively promotes oral health education in the community and is now pending charity registration with the OSCR.

The use of silver-based compounds as antimicrobial agents has been well-documented and common practice for more than 100 years in both medicine and dentistry. From wound dressings to water purification systems, Ag+ is able to destroy pathogens at concentrations of <50ppm. More recently, the use of silver diamine fluoride (SDF) in dentistry has been increasing with applications including caries prevention, arresting carious lesions and the treatment of sensitivity 1.

There are a vast number of products that have been used to deliver fluoride in the aim of preventing caries including milk, salt, toothpaste and varnish. It is thought that where SDF differs is that the silver salt component has a potent antibacterial effect with the ability to encourage the formation of calcified/sclerotic dentine while the fluoride provides a remineralising effect. As such, SDF has stimulated significant interest in the prevention and treatment of caries worldwide based on its ability to reduce instances of pain, ease of use, affordability, non-invasive nature and minimal clinical time for application 1.

SDF is a colourless topical agent with a large number of practical clinical applications in dentistry including 2:

1) Prevention and treatment of high caries risk patients including both children and adults.

2) Prevention and treatment of caries in patients who are medically compromised.

3) Treatment of root surface caries.

4) Treatment of dentine hypersensitivity.

SDF is commercially available in the UK as Riva Star by SDI. The formulation is based on two coloured capsules, silver and green, that must both be applied. Application of SDF is a relatively simple process. The teeth must be cleaned with prophy paste to remove plaque debris before being dried and isolated with cotton wool rolls. If applying close to the gingival margin the kit contains a gingival barrier or alternatively some Vaseline can be placed. The silver capsule is applied first followed by green that causes the formation of a white precipitate. Each capsule can be used to treat around five teeth (see Figs 1-3).

Where being used in the treatment of caries it is important that patients are aware that the aim is to arrest the lesion that will result in a dark appearance (Fig 3). Temporary staining of the gingivae is also possible. Repeated application, twice annually, is essential where the aim is to arrest a carious lesion or to treat dentine hypersensitivity.

Caries prevention
A systematic review by Rosenblatt et al. conducted a review of the literature on the use of SDF between 1966 and 2006, identifying 99 papers. The authors were able to conclude that SDF is more effective than fluoride varnish and may be a valuable preventative intervention. They also noted that SDF is a “safe, effective, efficient and equitable caries preventive agent that meets the criteria of the WHO millennium goals”1.

In 2017, a further review of the literature conducted by Contreras et al. found 33 publications meeting the inclusion criteria that were published between 2005 and 2016. The group were able to conclude that SDF is an “effective preventative treatment in a community setting” and that is “shows potential to arrest caries in the primary dentition and permanent first molars”3.

Caries treatment
Chu et al. carried out a study on the use of SDF in arresting carious lesions in 370 Chinese pre-school children aged three to five years old. They compared groups of children receiving SDF treatment, sodium fluoride varnish and a control. The children were followed up for 30 months receiving an intervention every three months.

Children in the SDF groups had a mean of 2.8 arrested lesions compared with a mean of 1.5 in the varnish group. They were able to conclude that the application of an SDF solution was more effective in arresting dentine caries in primary teeth compared with sodium fluoride vanish 4.

Similar results are echoed in a study by Lo et al. which followed 375 Chinese pre-school children over an 18-month period comparing groups of children receiving treatment with SDF, NaF varnish and a control. They found a mean of 0.4 new carious lesions in the SDF treated group compared with 1.2 in the control. They also found similar results in arresting active carious lesions with a mean of 2.8 arrested lesions in the SDF group compared to 1.5 in the NaF varnish group 5.

Clemens et al. treated 118 active lesions with SDF in a community dental clinic in Oregon. They were able to follow up 102 lesions on a three-monthly recall basis and found that 100 lesions were arrested by the first recall and all lesions by the second recall. The authors also noted no incidence of pain or infection and that the parents had a favourable view of the treatment modality 6.

Adults patients have also found a beneficial effect from SDF treatment. Zhang et al. followed up 227 elderly patients over 24 months who were provided with SDF and oral health education compared with a control group. They found a statistically significant result in that the SDF group had fewer root surface lesions than the control group. The authors concluded that SDF combined with oral health education was effective in preventing new root caries and arresting existing lesions in elderly patients 7.

Treatment of sensitivity
Castillo et al carried out a randomised control trial in 126 adult patients experiencing dentine hypersensitivity to assess the effectiveness of SDF as a desensitising agent. They found a reduction in sensitivity at seven days that was statistically significant (p<0.001) compared with the control group and were able to conclude that SDF is a clinically effective desensitising treatment 8.

Guidelines
In October 2017, the American Academy of Paediatric Dentistry issued the first ever evidence-based guideline for the use of SDF in the treatment of dental caries. This followed a systematic review of research between 1969 and 2016. The guideline hopes to lead to a more widespread adoption of SDF as a treatment for dental caries in paediatric and special needs patients 9.

The AAPD describe SDF as the “single greatest innovation in paediatric dental health in the last century aside from water fluoridation” noting the cost effective and pain-free benefits of treatment.

The systematic review on which the guideline is based notes no adverse effects but that a ‘downside’ is the black appearance of cavities. The potential to reduce the number of paediatric cases requiring sedation or GA is high.

The chairside guide suggests that patients who may benefit from SDF include 10:

  • High caries risk individuals with active cavitated carious lesions in anterior or posterior teeth
  • Patients with additional behavioural or medical challenges who present with cavitated carious lesions
  • Multiple cavitated lesions that may not all be treated in a single visit
  • Patients with limited access to dental care.
  • The chairside guide also suggests the following criteria for tooth selection 9:
  • No clinical signs of pulpal inflammation or reports of spontaneous pain
  • Cavitated lesions not encroaching on pulp
  • Lesions are accessible by a brush to apply SDF (orthodontic separators may be used to help gain access to interproximal regions).

Follow-up is recommended two to four weeks after treatment. Arrested lesions can subsequently be restored. However, where lesions are not restored, biannual re-application is recommended.

In conclusion, silver diamine fluoride is safe and effective in the prevention and treatment of dental caries as well as providing a further treatment modality in the management of dentine hypersensitivity. Application twice annually is a minimally invasive, cost-effective treatment that demonstrates a potentially vast benefit to patients of all ages.


References
1. Rosenblatt A, Stamford T and Niederman R. (2009). Silver Diamine Fluoride: A Caries “Silver-Fluoride Bullet”. Journal of Dental Research, 88(2), pp.116-125.

2. JUCSF protocol for caries arrest using silver diamine fluoride: rationale, indications, and consent. J Calif Dent Assoc. 2016 Jan; 44(1): 16–28.

3. Contreras et al. 2017. Effectiveness of silver diamine fluoride in caries prevention and arrest: a systematic literature review Gen Dent. 2017 May-Jun; 65(3): 22–29..

4. Chu C, Lo E and Lin H. (2002). Effectiveness of Silver Diamine Fluoride and Sodium Fluoride Varnish in Arresting Dentin Caries in Chinese Pre-school Children. Journal of Dental Research, 81(11), pp.767-770.

5. Lo E, Chu C and Lin H. (2001). A Community-based Caries Control Program for Pre-school Children Using Topical Fluorides: 18-month Results. Journal of Dental Research, 80(12), pp.2071-2074.

6. Clemens J, Gold J and Chaffin J. (2017). Effect and acceptance of silver diamine fluoride treatment on dental caries in primary teeth. Journal of Public Health Dentistry.

7. Chu C, Lo E and Lin H. (2002). Effectiveness of Silver Diamine Fluoride and Sodium Fluoride Varnish in Arresting Dentin Caries in Chinese Pre-school Children. Journal of Dental Research, 81(11), pp.767-770.

8. Castillo J, Rivera S, Aparicio T, Lazo R, Aw T, Mancl L and Milgrom P. (2010). The Short-term Effects of Diammine Silver Fluoride on Tooth Sensitivity. Journal of Dental Research, 90(2), pp.203-208.

9. Chairside Guide: Silver Diamine Fluoride in the Management of Dental Caries Lesions. AAPD Reference Manual v 39. No.6, 17/18. Accessed on http://bit.ly/AAPDchairsideguide


About the authors
Michael Dhesi
is a GDP who qualified in 2012 with BDS(Hons) from the University of Glasgow and has subsequently completed MFDS RCPS(Glasg) and an MSc in Advanced General Dental Practice at the University of Birmingham. Michael’s focus is in minimally invasive and adhesive restorative dentistry. He also has interests in the management of dental anxiety and oral surgery.

Clive Schmulian qualified from Glasgow University in 1993. Throughout his time in general dental practice, he has developed his clinical skills by obtaining a range of postgraduate qualifications, which in turn led him to develop an interest in digital imaging in both surgical and restorative dentistry. He is a director of Clyde Munro.

We are all too aware that mouth cancer is on the rise. More and more cases are being diagnosed every year with about 300,000 cases of lip and oral cancer reported globally1. In 2014, there were 7,680 cases of oral cancer in the UK2 and, since 1970 there has been a 93 per cent increase in the number of cases3.
Scotland remains a hot spot for oral cancer with higher incidence rates and lifetime risk compared to the rest of the UK.

Cancer Research UK predicts a further 33 per cent increase in oral cancer by 20353. Clearly, we need to act now to address this increasing problem. We, as a profession, have it within our power to do something; stand up, speak out and make some noise about mouth cancer. Our training and position in the community make us the ideal group of health care professionals to provide counsel to patients on risk reduction, screen for the disease and to empower patients with skills and knowledge to find the disease themselves at an early stage.

Risk factors
Traditionally, this has been a disease that affected older men. They have often smoked tobacco and drunk alcohol for many years. Now, that picture is beginning to change. Smoking and alcohol still remain important risk factors but more young people and women are developing this disease without traditional risk factors. Nine out of 10 cases of mouth cancer can be linked to a preventable cause4. Other risk factors include a diet low in fruit and vegetables, poor oral hygiene and the Human Papilloma Virus infection.

With global migration increasing it is likely we will see an increase in the use of smokeless tobacco, areca nut and betel quid in Scotland. There is also growing evidence of the adverse effect that shisha smoking has on health5. Therefore, we must think beyond the traditional risk factors.

A recent study revealed that the vast majority of patients developing head and neck cancer in Scotland are from the most deprived areas in our communities, therefore suggesting that this is a disease of inequality6. In fact, the deprivation gap for mouth cancer is the third highest amongst all cancers at 117 per cent7. Public health initiatives should take this into account when developing measures to address the burden of mouth cancer.

Prognosis
Dentists need to be vigilant when examining and screening our patients; we should have clear protocols and pathways in place for managing suspicious lesions and reviewing those lesions or mouths that simply ‘don’t look right’. Early detection is still recognised as the most important prognostic factor in mouth cancer8. Other prognostic factors include the aggressive nature of the tumour and the proliferation rate of the cells9.

Currently, the mainstay treatment for mouth cancer is high morbidity surgery. As a result of such major surgery, patients’ quality of life post surgery is vastly reduced. Treatment impacts on all aspects of life that we take for granted, such as enjoying meals, conversing freely and showing affection to loved ones. Although there have been great advances using free flap tissue repair to reconstruct surgical excision sites, this has had little to no impact on survival and prognosis, with only 53 per cent of patients surviving to five years post diagnosis10. Those that receive an early diagnosis have an 80-90 per cent chance of survival at five years. While those that present late with advanced disease have a much lower survival or if there is spread to other body systems then treatment is likely to be palliative.

Mouth cancer referral guidance
Dental patients should be examined for signs of malignancy as a part of the routine oral examination at every visit. The Scottish Referral Guidelines for suspected oral cancer11 identify a number of signs and symptoms which may represent malignancy (see Table 1 below). The guidelines recommend that those patients who present with the identified signs and symptoms which last for more than three weeks should be referred urgently to a specialist service according to local referral protocols.

The National Institute for Health and Care Excellence12 (NICE NG12) make similar recommendations and advise that patients who are referred urgently with suspected cancer should be given an appointment in the specialist service within two weeks of referral.

To improve early detection and thus survival, Scottish-based charity Let’s Talk About Mouth Cancer (LTAMC) work directly with the public as well as with professional groups. We advocate a shorter timescale than three weeks, instead recommending that patients should be referred urgently when signs and/or symptoms which are suspicious of mouth cancer do not resolve after just two weeks. The aim of this initiative is to reduce diagnostic delay as much as possible.

Diagnostic delay
Patient delay and professional delay contribute to the total diagnostic delay.

Patient delay
This is defined as “the period between the patient first noticing symptoms and their first consultation with a health care professional concerning those symptoms”13.

Approximately 30 per cent of patients diagnosed with mouth cancer will wait three months following the self discovery of signs and symptoms before attending a doctor or dentist14, 15. This may be because they attribute the symptoms to non-malignant, self-correcting conditions.

A study by Scott et al (2008)13 found that patients with better knowledge of signs and symptoms of mouth cancer are less likely to delay seeking advice. Knowledge about mouth cancer aids interpretation of symptoms and the decision to seek help. The same study also found that a low socio-economic background and deprivation are significantly higher in patients who delay seeking help. These patients also experience real or perceived limited ability to access healthcare. Some of the work of LTAMC aims to rectify some of these issues by educating the public about the signs and symptoms of mouth cancer, focusing on deprived and minority community groups.

Professional delay
It has been shown that lack of knowledge by general dental and medical practitioners about the signs, symptoms and risk factors of mouth cancer can also contribute to the delay in diagnosis. Patients will frequently present first to their doctor with mouth symptoms. A cross-sectional study in Dundee found that, compared to dentists, a significant number of doctors felt they had insufficient knowledge about the detection and prevention of mouth cancer16. Waiting lists and pressures in the health service may also contribute further to professional delay.

How to spot mouth cancer
As recommended in the guidelines, every patient attending for routine check-up should have a full head and neck soft tissue examination. A systematic approach should be routinely used to avoid missing any areas. A video of this can be seen on our website (www.ltamc.org/professional-resources).

Before any examination, a detailed history should be taken. For each area of concern, the patient should be asked about the length of time they have been aware of the lesion/symptoms and ascertain if there has been any pain, change in sensation or effect on function (speech, swallowing, eating). In many cases, however, early and even late tumours can be asymptomatic. It is also worth asking if a lesion has been present before and healed fully or partially. Of course, if the patient is unaware of the area, then questioning may be delayed until after detecting a suspicious lesion.

Extra-orally, the soft tissues should be checked for any asymmetry, swellings or lymphadenopathy; it is important to note any changes in texture and fixation. A hard, fixed lump in the neck is highly suggestive of tumour spread to the lymph nodes.

Intra-orally the oral mucosa has natural variation according to its anatomical site. It is important to be familiar with normal appearances as any changes need to be investigated. The Scottish Cancer Referral Guidelines11 recommend referral for cancer arising from the oral mucosa when there are persistent unexplained lumps, ulceration, unexplained swellings, red or mixed red and white patches of the oral mucosa. Proper and clear description of any lesion is fundamental, both for the sake of good record keeping and also to allow any referral to be as fulsome and informative as possible.

To cover all aspects of a lesion, these characteristics should be recorded and described:

  • Site – where the lesion is, note adjacent structures
  • Size – can be measured in millimetres with probe/ruler or relative to local anatomy (e.g. extending from mesial 34 to distal 36)
  • Colour – red, white or mixed (homogeneous/heterogeneous)
  • Texture – hard or soft, fixed or mobile, smooth or rough, induration
  • Border – well or poorly defined, raised or flat.

Based on all these findings, a decision must be made whether to monitor in practice, make a routine referral or to refer urgently. It is not necessary to arrive at a definitive diagnosis, rather a decision to refer for further investigation and appropriate treatment. The patient should be informed of the findings, possible diagnosis and also the reasoning for referral or monitoring in practice. The importance of attending arranged appointments must be stressed.

Click to open full size

Referrals quiz
Let’s take a few examples and put this into practice. Look at each of the cases below and their brief history. Try describing each as you would for a referral and decide whether you would monitor in practice, make a routine referral or refer urgently. Have a guess at the diagnosis as well. Remember, the triaging surgeon ultimately decides from your referral whether to allocate as urgent or routine, so quality of information is key.

Many lesions are not clear cut and easy to decide on management. You are not alone – if in doubt, seek the opinion of a colleague or send in a referral. In this case, the description and history you submit is essential for the receiving surgeon to adequately assess the urgency for appointment. Be reassured that the majority of urgent referrals after investigation are not cancerous but it is only possible to know that after appropriate tests.

It is vital to follow up a patient where the decision to monitor a lesion within practice or a routine referral has been made. In the instance there are any changes to the area, reconsider if the original decision needs to be altered. Likewise, when managing a lesion in practice first (e.g. ease traumatic denture, smooth sharp edge on tooth, prescribe antifungals), this must be reviewed after two weeks to gauge response. If not healed, then reappraise the suspected cause, treatment provided and potentially send a referral. Also, if the patient misses an appointment or has not received one within the expected time frame, contact the department to ensure one is arranged.

(Quiz answers are at the end of the article)

Empowering our patients
Recently, LTAMC has developed its strategy away from clinician-based screening in favour of patient empowerment – the focus has changed to teaching self examination for mouth cancer. Although a conventional oral examination by a clinician remains the most sensitive and specific method to detect mouth cancer cases17, teaching mouth cancer self examination empowers patients to recognise pathology in their mouth and may increase awareness.

A Cochrane review published in 2013 found that mouth cancer self examination had similar sensitivity and specificity to breast self examination17. Teaching mouth cancer self examination can be used as a tool in general practice to increase awareness of mouth cancer. It can form part of a general discussion about the signs, symptoms and risk factors of mouth cancer. The thorough, logical mouth self examination process follows five simple steps and is demonstrated in the graphic above. The key messages are to check for: red or white patches; lumps in the mouth that grow; ulcers in the mouth that do not heal; and persistent soreness/discomfort.

The advice is to attend the dentist or general medical practitioner if any of these signs/symptoms do not resolve in two weeks and importantly, to alert the practitioner to a concern about mouth cancer. Patients should be encouraged that mouth self examination is easy, and only requires a light source and a mirror. The aim is simply to empower patients to recognise normal tissues, and to present early if something changes. The mantra “If in doubt, check it out” should be repeated often.

LTAMC has also produced an instructive video aimed at teaching the general public how to perform a mouth cancer self examination. It can be found at youtu.be/WQaujHXauso

The video has been viewed more than 4,500 times in the UK, USA, Japan, Vietnam and India, indicating a worldwide interest. As mentioned above, a recent study has shown that approximately 30 per cent of patients with mouth cancer delay seeking help following discovery of symptoms for more than three months13. As early diagnosis is a key factor for improving prognosis and survival, we as dentists must tackle the lack of recognition of symptoms among our patients.

Lack of insight into initial symptom interpretation and lack of knowledge of mouth cancer have been shown to be significant variables which contribute to patient delay in seeking help13, and are issues that may be easily modified with targeted interventions by general dental practitioners.

Conclusions
Mouth cancer is increasing at an alarming rate and yet large sections of the public know little of the risk factors or signs and symptoms of the disease. Despite the fact that about half the population attend a dentist regularly for dental check-ups, many cases present at a late stage with a correspondingly poor prognosis. Survival has not improved substantially in the past 50 years and there is no treatment available that can transform the poor survival of someone with late stage disease to the much better survival of someone with early stage disease; the only thing that can do this is early diagnosis.

The work of LTAMC is firmly focused on teaching the public as well as professionals to diagnose mouth cancer early. We hope to break down health inequalities and empower as many people as possible to recognise the disease and its risk factors to improve survival. We call it our empowerment journey, so “Let’s talk about mouth cancer!”

Quiz Answers:

Case one
Outcome: Monitor in practice.
Diagnosis: Lichenoid lesion/lichen planus.

Case two
Outcome: Urgent referral.
Diagnosis: Dysplastic lesion or early cancer.

Case three
Outcome: Urgent referral.
Diagnosis: Squamous cell carcinoma.

Case four
Outcome: Urgent referral.
Diagnosis: Squamous cell carcinoma.

Case five
Outcome: Routine referral.
Diagnosis: Human Papillomavirus related papilloma.

Case six
Outcome: Urgent referral.
Diagnosis: Squamous cell carcinoma.

About the authors
This article was co-authored by the five trustees of the Scottish charity Let’s talk about mouth cancer (SC045100):

  • Dr Niall McGoldrick BDS MFDS RCPS(Glasg), specialty registrar in dental public health.
  • Mr Ewan MacKessack-Leitch BDS(Hons) MFDS RCPS(Glasg), GDP, Fife.
  • Dr Stephanie Sammut FDS (OS), MClinDent, MOral Surg, MFDSRCPS,
    consultant oral surgeon.
  • Dr Orna Ni Choileain BDS(Hons) MFDS RCSEd, medical student,
    Trinity College Dublin.
  • Prof Victor Lopes PhD FRCS, consultant maxillofacial surgeon.

Website: www.ltamc.org

Twitter: @couldbeUrmouth

Facebook: www.facebook.com/letstalkaboutmouthcancer

References
1. N Johnson, A Chaturvedi: Global burden of oral cavity and pharyngeal cancers, Global Oral Cancer Forum: 2016

2. C R Smittenaar, K A Petersen, K Stewart, N Moitt. Cancer incidence and mortality projections in the UK until 2035. Br J Cancer. 2016 Oct 25; 115(9): 1147–1155

3. www.cancerresearchuk.org [Internet]. 2017 Available from:
www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/oral-cancer#heading-Zero

4. www.cancerresearchuk.org [Internet]. 2017 Available from:
www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/head-and-neck-cancers/risk-factors#heading-Zero

5. Ziad M El-Zaatari, Hassan A Chami, Ghazi S Zaatari Health effects associated with waterpipe smoking. Tob Control. 2015 Mar; 24(Suppl 1): i31–i43.

6. Purkayastha M, McMahon AD2, Gibson J, Conway DI. Trends of oral cavity, oropharyngeal and laryngeal cancer incidence in Scotland (1975-2012) – A socioeconomic perspective. Oral Oncol. 2016 Oct; 70-5. doi: 10.1016/j.oraloncology.2016.08.015. Epub 2016 Aug 31.

7. www.cancerresearchuk.org [Internet]. 2017 Available from
www.cancerresearchuk.org/health-professional/cancer-statistics/incidence/deprivation-gradient#heading-One

8. Gómez, I., Seoane, J., Varela-Centelles, P., Diz, P. and Takkouche, B. (2009), Is diagnostic delay related to advanced-stage oral cancer? A meta-analysis. European Journal of Oral Sciences, 117: 541–546. doi:10.1111/j.1600-0722.2009.00672.x

9. Warnakulasuriya S. Prognostic and predictive markers for oral squamous cell carcinoma: The importance of clinical, pathological and molecular markers. Saudi J Med Med Sci 2014;2:12-6

10: www.cancerresearchuk.org [Internet ]Available from
www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/head-and-neck-cancers/survival#heading-Zero

11. Healthcare improvement Scotland. Scottish referral guidelines for suspected cancer 2013 ( updated in August 2014) available online
www.healthcareimprovementscotland.org/our_work/cancer_care_improvement/programme_resources/scottish_referral_guidelines.aspx [last accessed 31 July 2017]

12. National Institute for health care and excellence. Suspected cancer: recognition and referral – NICE Guideline NG12. 2015 (last updated July 2017) available online www.nice.org.uk/guidance/ng12/resources/suspected-cancer-recognition-and-referral-pdf-1837268071621 [last accessed 31 July 2017]

13. Scott S, McGurk M, Grunfeld E. Patient delay for potentially malignant oral symptoms. Eur J Oral Sci. 2008;116 2:141–147.

14. Scott SE, Grunfeld EA, McGurk M. Patient’s delay in oral cancer: a systematic review. Community Dent Oral Epidemiol. 2006;34 5:337–343.

15. Allison P, Locker D, Feine JS. The role of diagnostic delays in the prognosis of oral cancer: a review of the literature. Oral Oncol. 1998;34 3:161–170. [PubMed]

16. Carter L, Ogden GR Oral Cancer awareness of general medical and general dental practitioners Br Dent J. 2007 Sep 8;203(5):E10; discussion 248-9. Epub 2007 13 Jul.

17. Walsh T, Liu JLY, Brocklehurst P, Glenny AM, Lingen M, Kerr AR, Ogden G, Warnakulasuriya S, Scully C. Clinical assessment to screen for the detection of oral cavity cancer and potentially malignant disorders in apparently healthy adults. Cochrane Database of Systematic Reviews 2013, Issue 11.

I’ve been teaching in the area of child protection and dentistry for approximately eight years and completed a masters by research in 2013 on Oral Disease in Vulnerable Children and the Dentist’s Role in Child Protection1. I’m now doing a PhD looking at what is involved in the decision by dental team members to refer suspected cases and how serious game methodology might support this context.

What is clear to me is that often decisions in this area are difficult and uncomfortable to make, so this article looks at what is expected of us as members of the dental team (whether we are dentists, dental nurses, therapists or technicians) and what this means from a practical point of view in our daily working lives.

The General Dental Council states that all members of the dental team “must raise any concerns you may have about the possible abuse or neglect of children” and “must know who to contact for further advice and how to refer concerns to an appropriate authority”2. They also state “you must find out about local procedures for the protection of children” and “you must follow these procedures if you suspect a child or vulnerable adult might be at risk because of abuse or neglect”2.

These wide-ranging statements mainly cover child protection (defined as activities undertaken to protect specific children who are suffering, or are at risk of suffering significant harm) but also bring in elements of safeguarding (defined as measures taken to minimise the risk of harm to all children).

From a practical point of view, there is the need to identify what your concerns are. This could be anything from unexplained (or inadequately explained) injuries, concerns about dental neglect, concerns about general neglect, a general lack of engagement with dental services to witnessing a child being physically abused in your waiting room or surgery. It is the vast spectrum of these concerns which make it difficult to provide what so many people ask for – a step-by-step guide for any conceivable situation – because there are so many different situations that could present themselves.

Some health boards have produced flowcharts for dental teams to follow and there is also a summary flowchart available on the Child Protection and the Dental Team website which are very helpful3. For some of these situations, the dental team members that I have been privileged to speak to (during my research and teaching) find the decision of what to do next straightforward, but for other situations it is more difficult.

It has already been well documented that there remains a 26 per cent gap between the proportion of general dental practitioners who have suspected child abuse or neglect in one or more of their paediatric patients (37 per cent) and the proportion that have referred suspected cases (11 per cent)4. Quantitative methods have consistently shown that the gap between dentists who suspect and refer in Scotland is affected by lack of certainty of the diagnosis, fear of violence to the child, fear of consequences to the child from statutory agencies, lack of knowledge of referral procedures, fear of litigation, fear of violence to the general dental practitioner and concerns of impact on dental practices4, 5.

So, let’s explore four of the most common things I’m asked about and hopefully it will be helpful to all of the team.

1. The child with caries whose family don’t engage with services
I’m asked about this situation a lot, probably because it is a common occurrence. We know caries is still common in children and statistics say 94 per cent of children in Scotland are registered with a general dental practitioner, with 85 per cent having seen their dentist in at least the last two years6. Perhaps a dentist has referred a patient for extractions under general anaesthetic but the patient is never taken to the assessment appointment and the dentist gets a letter back from the public dental service or the hospital dental service discharging them back to their care because they’ve not managed to see them.

Or perhaps it is a family that come for their check-ups but don’t bring the children back to have their treatment completed, or ones who repeatedly cancel, or don’t book check-ups when they get their reminder letters and the dental teams only end up seeing them sporadically. Or it may be children who have required extractions under general anaesthesia for removal of all their primary teeth but then don’t come back until they are aged seven or so and now have unrestorable caries in all their permanent molars.

These situations are difficult and all of them are examples of dental neglect, which is defined by the British Society of Paediatric Dentistry as “the persistent failure to meet a child’s basic oral health needs, likely to result in the serious impairment of a child’s oral or general health or development”7. Although dental caries is still common in children, signs such as failing to complete courses of dental treatment, failing to listen and act on preventive advice given by dental teams, children returning in pain repeatedly, children requiring repeated general anaesthetics due to dental issues or children who are repeatedly not brought to their dental appointments, are all concerning patterns of behaviour which are likely to result in the impairment of a child’s oral or general health or development7,8.

Untreated dental caries may be one of the first signs of child abuse or neglect9. Neglect should be considered if parents have access to, but persistently fail to obtain treatment for their child’s tooth decay10. Research also suggests that abused/neglected children are more likely to have untreated decayed teeth, significantly more dental plaque and gingival inflammation than non-abused/non-neglected children1113.

Many practitioners whom I have spoken to then say: “Well if I have to refer every patient like that, I would be referring at least 60 per cent or more of my paediatric cohort!” This really depends on what practitioners mean by the term ‘refer’. All of these situations do require some action to be taken, but not all will necessitate an immediate referral to social work. There is very sensible advice given for this type of scenario in Child Protection and the Dental Team (CPDT) which recommends a three-level response to concerns about dental neglect, namely preventive dental team management, preventive multi-agency management, child protection referral3.

Preventive dental team management involves “raising concerns with parents, offering support, setting targets, keeping records and monitoring progress. The initial focus should be on relief of pain accompanied by preventive care. In order to overcome problems of poor attendance, dental treatment planning should be realistic and achievable and negotiated with the family”3. This is often all that is required and, in reality, is probably what most dental teams do on a day-to-day basis (although there is no evidence from research to prove this is the case).

Fully implementing a preventive dental team management strategy can have impacts on a practice and those impacts will have to be discussed as a team, for example deciding who will deal with contacting the family if agreed appointments are cancelled or missed. The CPDT website gives an example of how it might be put into practice3. The areas where research has suggested dental teams could improve upon are ‘setting targets’ and ‘monitoring progress’14. If this level of response to the concerns is not working or there is a breakdown of communication or the child/family has more complex needs then preventive multi-agency management may be more appropriate.

Preventive multi-agency management involves liaising with other professionals who might be involved with the family. Examples of other professionals could include the health visitor (for pre-school children), the general medical practitioner, the child’s social worker (if they already have one) or the child’s named person. The aim of this liaison is “to see if concerns are shared and to clarify what further steps are needed”3. There is a sample letter to a health visitor freely available on the CPDT website which can be used to assist with multi-agency working for children under five years old3.

A joint plan of action should be agreed (for example as a dental practice we will arrange appointments on these dates and the child’s social worker will facilitate attendance, or the health visitor will arrange a home visit by a dental health support worker to facilitate registration and attendance at our dental practice). A date should be specified for review of the action plan so that it can be checked that progress is being made.

If there is any point in the processes above where things begin to deteriorate, or if it is felt at any time that the child is at risk of suffering significant harm (this can include things like a child being in pain for more than a couple of days due to toothache and this is happening on more than one occasion), then any member of the dental team can make a child protection referral. Some dental team members struggle to work out when things become significant. A good rule of thumb can be that if you wouldn’t let children in your own circle of family or friends go through it, then it is probably significant.

Child protection referrals should be made according to the local procedures of where you work. In Scotland, a child protection referral is made either to the police or local children’s social work team (referrals can also be made to the Children’s Reporter but follow your local guidelines). If you do not already know your local contact numbers you can, currently, find them out by visiting www.withscotland.org/public-local-councils and typing in the postcode of the child you are concerned about. (Please note: This website address is likely to change in the future as WithScotland no longer exists, but many of their functions have been taken over by the new Centre for Child Wellbeing and Protection www.stir.ac.uk/ccwp/)

2. How do I make a child protection referral?
The majority of child protection referrals will involve a telephone call to your local social work office (Children and Families office ideally but in many areas in Scotland you will go through Social Care Direct) in the first instance explaining your concerns and stating you wish to make a child protection referral. Write down the names and job titles of everyone you speak to. The telephone referral should then be followed up in writing normally within 48 hours. This may involve completion of a shared referral form, or notification of concerns form (same form just different names), or similar, with one copy going into the child’s dental notes, one copy sent to the social work office that you spoke to on the phone, and, depending on your local procedures, another copy may be sent to your local child protection unit (CPU) or similar (or you may just have to notify your CPU by email or phone).

3. Will the family know I’ve referred them?
The short answer to this is that they might. In most situations it is best practice to tell the family what your concerns are and why you are referring them to social services but there will, of course, be some situations where the family don’t know, either because you can’t get in contact with them or you may believe that you would put the child in more danger if the family were aware of the referral.

You can refer anonymously but, bear in mind that if the concerns you have are related to non-attendance with you or concerns about something dental, then even if you refer anonymously the family will, probably, be able to work out where the referral came from so it is a much better situation if you have informed them the referral is being made.

4. I’m worried about how the family will react
Many dental professionals assume telling a family you are going to contact social work will be bad news, but for some families it will be the first time anyone has actually offered them any help. As members of the dental team, we quite often have to break bad news to our patients (e.g. “I’m sorry I can’t save the tooth, it needs to be extracted”). Being concerned is a natural human response but it is helpful to think through all the reactions that you would be worried about and how, as a team, your practice will manage them.

For example, if the family are angry and choose to de-register from your practice, you can’t always prevent that from happening but you would want to pass that information on to the other agencies involved such as the social work office you referred to. I suggest being quite clear in your practice about what your professional responsibilities are and having posters or information up in waiting areas promoting that you take the safeguarding of children and vulnerable adults seriously.

Many dental team members have told me they are worried that as they live in a small town that word will spread, or their own children will be targeted at school or they will be threatened by the families involved. My advice is that if you are threatened, inform the police and relevant social work office involved. If your own children get picked on because of rumours, approach the school as you would do about any episode of bullying your child may experience and talk to your child about the nature of your job (e.g. “You know mummy/daddy is a dentist/dental nurse/practice manager and looks after people’s teeth, but I also have a responsibility to make sure the children that I see at work are alright and are being looked after properly”). If your practice gets branded as “the ones who call social work”, take this as a good thing as it means you are actively looking out for and promoting the welfare of your paediatric patients. There are many experts out there who can give advice on how to use it as a
‘practice builder’.

Conclusion
Ultimately, it is not only our professional responsibility, but also an ethical responsibility to protect and safeguard those in society who can’t do it for themselves. Doing nothing when you have a concern is never an option – you would probably continue to worry and you cannot predict what the impact on the child would be.

Unfortunately, I have had to look at statements from dental team members when something awful has happened to one of their paediatric patients, and so often there have been warning signs (e.g. multiple missed appointments, failure to complete treatment) but the dental teams did not record or raise any concerns. Clearly I have the benefit of hindsight and experience but my hope is that as more dental teams think about and practise looking out for the wellbeing of their paediatric patients, then perhaps I’ll see fewer awful things happening. Or, if they are still happening, I’ll see real evidence that the dental teams involved did everything they could to help the child.

About the author
Christine Park is a senior clinical university teacher at Glasgow Dental Hospital and School, and honorary consultant in paediatric dentistry at NHS Greater Glasgow and Clyde.

References
1. Harris CM. Oral disease in vulnerable children and the dentist’s role in child protection [MSc Thesis] Glasgow: University of Glasgow; 2013. Available at: http://theses.gla.ac.uk/4150/1/2013harrismsc.pdf.pdf Accessed 03/08/2017

2. General Dental Council. Standards for the Dental Team. Guidance on Child Protection and Vulnerable Adults. GDC; 2013. Available at www.gdc-uk.org/professionals/standards/team Accessed 03/08/2017

3. Harris J, Sidebotham P, Welbury R et al. Child protection and the dental team. An introduction to safeguarding children in dental practice. Sheffield: Committee of Postgraduate Dental Deans and Directors, 2006. Available at: bda.org/childprotection Accessed 03/08/2017

4. Harris CM, Welbury, R, Cairns, AM. The Scottish dental practitioner’s role in managing child abuse and neglect. Br Dent J 2013; 214(E24):1–5. Available at: dx.doi.org/10.1038/sj.bdj.2013.435 Accessed 03/08/2017

5. Cairns AM, Mok JYQ, Welbury RR. The dental practitioner and child protection in Scotland. Br Dent J 2005; 199(8):517–520; discussion 512; quiz 530–531.

6. ISD Scotland. Dental Statistics – NHS Registration and Participation. A National Statistics Publication for Scotland; 2017. Available at:
www.isdscotland.org/Health-Topics/Dental-Care/Publications/2017-01-24/2017-01-24-Dental-Report.pdf?49161928893 Accessed 03/08/2017

7. Harris JC, Balmer RC, Sidebotham PD. British Society of Paediatric Dentistry: a policy document on dental neglect in children. Int J Paediatr Dent 2009. Available at: http://bspd.co.uk/Portals/0/Public/Files/PolicyStatements/Dental%20Neglect%20In%20Children.pdf Accessed 03/08/2017

8. Balmer R, Gibson E, Harris J. Understanding child neglect. Current perspectives in dentistry. Prim Dent Care 2010; 17: 105–109.

9. Blumberg ML, Kunken FR. The dentist’s involvement with child abuse.
NY State Dent J 1981; 47:65–69.

10. National Collaborating Centre for Women’s and Children’s Health (2009). When to suspect child maltreatment: full guidance. Clinical Guideline 89. National Institute for Health and Clinical Excellence. Royal College of Obstetricians and Gynaecologists: London. Available at www.nice.org.uk/guidance/cg89/evidence/cg89-when-to-suspect-child-maltreatment-full-guideline2 Accessed 03/08/2017

11. Greene PE, Chisick MC, Aaron GR. A comparison of oral health status and need for dental care between abused/neglected children and non-abused/non-neglected children. Pediatr Dent 1994;16:41-45

12. Valencia-Rojas N, Lawrence HP, Goodman D. Prevalence of early childhood caries in a population of children with history of maltreatment. J Public Health Dent 2008;68(2):94-101

13. Montecchi PP, Di Trani M, Sarzi Amadè D, et al. The dentist’s role in recognizing childhood abuses: study on the dental health of children victims of abuse and witnesses to violence. Eur J Paediatr Dent 2009; 10(4):185-187.

14. Harris JC, Elcock C, Sidebotham PD, Welbury RR. Safeguarding children in dentistry: 2. Do paediatric dentists neglect child dental neglect? Br Dent J 2009;206: 465 – 470

In 2011, the Scottish Dental Clinical Effectiveness Programme (SDCEP) published clinical guidance on the Oral Health Management of Patients Prescribed Bisphosphonates. This was in response to reports in the literature describing a rare side effect in patients treated with these drugs, bisphosphonate-related osteonecrosis of the jaw (BRONJ)1.

Bisphosphonates are prescribed to reduce bone resorption in patients with osteoporosis and other non-malignant diseases of bone and to reduce the symptoms and complications of metastatic bone cancer. The drugs persist in the body for a significant period of time; alendronate has a half-life in bone of around 10 years2. As dental extractions appeared to be a risk factor for this oral complication, there was a need for guidance providing clear and practical advice for dentists in primary care on how to provide care for patients prescribed these drugs.

Since 2011, several other drugs have been implicated in what is now referred to as medication-related osteonecrosis of the jaw (MRONJ). The condition has been observed in patients treated with the anti-resorptive drug denosumab which, like the bisphosphonates, is indicated for the prophylaxis and treatment of osteoporosis and to reduce skeletal-related events associated with metastasis. Another drug class implicated in MRONJ is the anti-angiogenics, which target the process by which new blood vessels are formed and are used in cancer treatment to restrict tumour vascularisation. At the time of writing, the Medicines and Healthcare products Regulatory Agency (MHRA) has published Drug Safety Updates warning of the risk of MRONJ for three anti-angiogenic drugs: bevacizumab, sunitinib and aflibercept3,4.

Development of the updated SDCEP guidance
In response to these developments, SDCEP convened a second guidance development group (GDG) in 2015 to update the guidance. The GDG included consultants of various dental specialities, primary care dental practitioners, medical specialists and two patient representatives, who provided feedback on patient views and perspectives.

Pre-publication research was carried out by TRiaDS (Translation Research in a Dental Setting, www.triads.org.uk), who work in partnership with SDCEP, including a national survey of users of the first edition of the guidance and interviews with dentists, pharmacists and doctors. The findings informed the updating of the guidance and have been used as the basis for an implementation questionnaire and a national research audit.

A systematic and comprehensive search of the literature was conducted to inform the recommendations in the guidance. The quality of the evidence and strength of each of the key recommendations is stated clearly in the guidance with a brief justification in the accompanying text. A more in-depth explanation of the evidence appraisal and formulation of recommendations is provided in an accompanying methodology document.

NICE has accredited the process used by SDCEP to produce Oral Health Management of Patients at Risk of Medication-related Osteonecrosis of the Jaw, which means users can have high confidence in the quality of the information provided in the guidance. Accreditation is valid for five years from 15 March 2016. More information on accreditation can be viewed at www.nice.org.uk/accreditation

Prior to publication, the guidance was scrutinised through external consultation and peer review and it is endorsed by several of the Royal Colleges, Public Health England and Department of Health (Northern Ireland).

Medication-related osteonecrosis of the jaw
MRONJ was first reported by Marx in 20031 and is defined as exposed bone, or bone that can be probed through an intraoral or extraoral fistula, in the maxillofacial region that has persisted for more than eight weeks in patients with a history of treatment with anti-resorptive or anti-angiogenic drugs, and where there has been no history of radiation therapy to the jaw or no obvious metastatic disease to the jaws5. Risk factors include the underlying medical condition for which the patient is being treated, cumulative drug dose, concurrent treatment with systemic glucocorticoids, dentoalveolar surgery and mucosal trauma. It is important to note that MRONJ is a rare side-effect of treatment with anti-resorptive and anti-angiogenic drugs and, although invasive dental treatment is a risk factor, it does not cause the disease.

At present, the pathophysiology of the disease has not been fully determined and current hypotheses for the causes of necrosis include suppression of bone turnover, inhibition of angiogenesis, toxic effects on soft tissue, inflammation or infection5. It is likely that the cause of the disease is multi-factorial, with both genetic and immunological elements.

Incidence
Estimates of incidence and prevalence vary due to the rare nature of MRONJ. It appears clear that patients treated with anti-resorptive or anti-angiogenic drugs for the management of cancer have a higher MRONJ risk than those being treated for osteoporosis or other non-malignant diseases of bone. This is likely to be due, in part, to the substantially larger doses of the drugs that cancer patients receive.

For patients being treated with anti-resorptive or anti-angiogenic drugs for the management of cancer, the risk of MRONJ approximates 1 per cent59, which suggests that each patient has a one in 100 chance of developing the disease. However, the risk appears to vary based on cancer type and incidence in patients with prostate cancer or multiple myeloma may be higher.

For patients taking anti-resorptive drugs for the prevention or management of non-malignant diseases of bone (e.g. osteoporosis, Paget’s disease), the risk of MRONJ approximates 0.1 per cent or less2,5,7, 1017, which suggests that each patient has between a one in 1,000 and one in 10,000 chance of developing the disease (Table one).

Patients who take concurrent glucocorticoid medication or those who are prescribed both anti-resorptive and anti-angiogenic drugs to manage their medical condition may be at higher risk.

The incidence of MRONJ after tooth extraction is estimated to be 2.9 per cent in patients with cancer and 0.15 per cent in patients being treated for osteoporosis18.

Risk factors
As outlined previously, the most significant risk factor for MRONJ is the underlying medical condition for which the patient is being treated. Dentoalveolar surgery, or any other procedure that impacts on bone, is also a risk factor, with tooth extraction a common precipitating event1922. However, MRONJ can occur spontaneously without the patient having undergone any recent invasive dental treatment.

The MRONJ risk in patients who are being treated with bisphosphonates is thought to increase as the cumulative dose of these drugs increases. One study found a higher prevalence of MRONJ in osteoporosis patients who had taken oral bisphosphonates for more than four years compared to those who had taken the drugs for less than four years13. There is currently no evidence to inform an assessment of MRONJ risk once a patient stops taking a bisphosphonate drug. Therefore, it is advised that patients who have taken bisphosphonate drugs in the past should continue to be allocated to the risk group they were assigned to at the time the drug treatment was stopped.

The effect of denosumab on bone turnover diminishes within nine months of treatment completion14, 23. Therefore, patients who have stopped taking denosumab should be considered to still have a risk of MRONJ until around nine months after their final dose. Anti-angiogenic drugs are not thought to remain in the body for extended periods of time.

Chronic systemic glucocorticoid use has been reported in some studies to increase the risk for MRONJ when taken in combination with anti-resorptive drugs20, 2427. The combination of bisphosphonates and anti-angiogenic agents has also been associated with increased risk of MRONJ20, 28. The risk appears to be increased if the drugs are taken concurrently or if there has been a history of bisphosphonate use.

Despite these risk factors, the majority of patients are able to receive all their dental treatment in primary care, with referral only appropriate for those with delayed healing.

Guidance recommendations
The aim of the SDCEP guidance is to assist and support primary care dental teams in providing appropriate care for patients prescribed anti-resorptive or anti-angiogenic drugs and to encourage a consistent approach to their oral health management. The guidance also aims to empower dental staff to provide routine dental care for this patient group within primary care thereby minimising the need for consultation and referral to secondary care.

Risk assessment
The guidance advises practitioners to assess and record whether a patient taking anti-resorptive or anti-angiogenic drugs is at low risk or higher risk of developing MRONJ based on their medical condition, type and duration of drug therapy and any other complicating factors. An up-to-date medical history is therefore essential in identifying those patients who are, or have been, exposed to the drugs and to identify any additional risk factors, such as chronic use of systemic glucocorticoids. Careful questioning of the patient may be required, along with communication with the patient’s doctor, to obtain more information about the patient’s medical condition and drug regimen(s).

The low-risk category includes those patients who have been treated for osteoporosis or other non-malignant diseases of bone with bisphosphonates for less than five years or with denosumab and who are not taking concurrent systemic glucocorticoids. The higher risk category includes cancer patients and also those being treated for osteoporosis or other non-malignant diseases of bone who have other modifying risk factors. Figure two illustrates how risk should be assessed for each individual patient.

The risk of MRONJ should be discussed with patients but it is important that they are not discouraged from taking their medication or from undergoing dental treatment. The guidance includes details of the points which should be covered in such a discussion and patient information leaflets are also available to facilitate this dialogue. As with all patients, the risks and benefits associated with any treatment should be discussed to ensure valid consent.

Initial care
Ideally, patients should be made as dentally fit as feasible before commencement of their anti-resorptive or anti-angiogenic drug therapy. However, it is acknowledged that this may not be possible in all cases and in these situations, the aim should be to prioritise preventive care in the early stages of drug therapy. Due to their increased MRONJ risk, it is particularly important that cancer patients undergo a thorough dental assessment, with remedial dental treatment where required, prior to commencement of drug therapy. It may also be appropriate to consider consulting an oral surgery or special care dentistry specialist for advice on clinical assessment and treatment planning for these medically complex patients.

As part of this initial management, patients should be given personalised preventive advice to help them optimise their oral health. The importance of a healthy diet, maintaining excellent oral hygiene and regular dental checks should be emphasised and patients should be encouraged to stop smoking and limit their alcohol intake where appropriate. They should also be advised to report any symptoms such as exposed bone, loose teeth, non-healing sores or lesions, pus or discharge, tingling, numbness or altered sensations, pain or swelling as soon as possible.

The guidance recommends prioritising care that will reduce mucosal trauma or may help avoid future extractions or any oral surgery or procedure that may impact on bone. Radiographs should be considered to identify possible areas of infection and pathology and any remedial dental work, such as extraction of teeth of poor prognosis or treatment of periodontal disease, should be undertaken without delay. It may also be appropriate to consider prescribing high fluoride toothpaste for these patients.

Continuing care
Recommendations for continuing care advise practitioners to carry out all routine dental treatment as normal and to continue to provide personalised preventive advice in primary care. For low-risk patients, straightforward extractions and other bone-impacting treatments can be performed in primary care. A more conservative approach is advised in higher risk patients, with greater consideration of other, less invasive alternative treatment options. However, if extraction or other bone-impacting procedure remains the most appropriate course of action, these can be carried out in primary care in this patient group. There is no benefit in referring low or higher-risk patients to a specialist or to secondary care based purely on their exposure to anti-resorptive or anti-angiogenic drugs and it is likely to be in patients’ best interests to be treated wherever possible by their own GDP in familiar surroundings.

There is currently insufficient evidence to support the use of antibiotic or topical antiseptic prophylaxis specifically to reduce the risk of MRONJ following extractions or procedures that impact on bone2932. Extraction or oral surgery sites should be reviewed, with healing expected by eight weeks. Evidence of delayed healing at eight weeks should be considered a sign of possible MRONJ. Figure three outlines the management of patients prescribed anti-resorptive or anti-angiogenic drugs.

Management of patients with suspected MRONJ
The treatment of MRONJ is beyond the scope of the guidance and patients with suspected MRONJ should be referred to a specialist in line with local protocols. Signs and symptoms of MRONJ include delayed healing following a dental extraction or other oral surgery, pain, soft tissue infection and swelling, numbness, paraesthesia or exposed bone. Patients may also complain of pain or altered sensation in the absence of exposed bone. Although the majority of cases of MRONJ occur following a dental intervention that impacts on bone, some can occur spontaneously. A history of anti-resorptive or anti-angiogenic drug use in these patients should alert practitioners to the possibility of MRONJ.

Guidance format
The main SDCEP guidance document provides practical advice and recommendations to inform the assessment of the patient’s MRONJ risk, the optimisation of their oral health during the initial phase of drug treatment and their ongoing care. A supplementary Guidance in Brief, which summarises the main recommendations, is also available.

Additional tools have been developed to support the implementation of the guidance, including patient information leaflets and information for prescribers and dispensers. The aim of the patient information leaflets is to make patients aware of the risk of MRONJ, the importance of continuing to take their medication and ways they can reduce their MRONJ risk. The leaflets provide a basis for further communication between the patient and their dentist and, ideally, should be provided to patients identified as being at risk of MRONJ at the commencement of their
drug treatment.

The guidance and the supporting documents are freely available via the SDCEP website (www.sdcep.org.uk).

Future research
MRONJ is a rare condition and consequently there is a lack of high-quality evidence on which to base guidance recommendations. High-quality research studies are required to determine the efficacy of MRONJ prevention protocols, both in the context of routine dental care and in those patents who require an extraction or procedure which impacts on bone. As an adverse drug reaction, MRONJ is monitored by the MHRA (www.mhra.gov.uk) and dental practitioners are encouraged to notify the MHRA of any suspected cases via the Yellow Card Scheme (www.yellowcard.mhra.gov.uk).
Reporting is confidential and patients should also be encouraged to report via the scheme.

It should be noted that the use of anti-angiogenic drugs in cancer is an expanding field, and it is likely that any future medications with these modes of action may also have an associated risk of MRONJ. The establishment of a national database to monitor cases of MRONJ could inform some of the research areas highlighted above and may also serve to identify other drugs which could be implicated in the disease.

As with all its guidance publications, SDCEP plans to review the recommendations in this guidance three years after publication and revise them if new evidence or experience emerges and indicates that this is appropriate.

About the author
Samantha Rutherford is a research and development manager for guidance development within the Scottish Dental Clinical Effectiveness Programme (SDCEP). She has led the development of a number of SDCEP guidance projects and was the project lead for the Oral Health Management of Patients at Risk of Medication-related Osteonecrosis of the Jaw guidance, which was published in 2017. Samantha has a PhD in medicinal chemistry and prior to her involvement in guidance development, she was a research scientist in the pharmaceutical industry.

References
1. Marx RE. Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing epidemic. Journal of Oral and Maxillofacial Surgery. 2003;61(9):1115-7.

2. Khan SA, Kanis JA, Vasikaran S, Kline WF, Matuszewski BK, McCloskey EV, et al. Elimination and biochemical responses to intravenous alendronate in postmenopausal osteoporosis. Journal of Bone and Mineral Research. 1997;12(10):1700-7.

3. MHRA. Aflibercept (Zaltrap): Minimising the risk of osteonecrosis of the jaw. Drug Safety Update. Apr 2016;9(9).

4. MHRA. Bevacizumab and sunitinib: Risk of osteonecrosis of the jaw. Drug Safety Update. Jan 2011;4(6):A1.

5. Ruggiero SL, Dodson TB, Fantasia J, Goodday R, Aghaloo T, Mehrotra B, et al. American Association of Oral and Maxillofacial Surgeons position paper on medication-related osteonecrosis of the jaw -2014 update. Journal of Oral and Maxillofacial Surgery. 2014;72(10):1938-56.

6. Khan AA, Morrison A, Hanley DA, Felsenberg D, McCauley LK, O’Ryan F, et al. Diagnosis and management of osteonecrosis of the jaw: a systematic review and international consensus. Journal of Bone and Mineral Research. 2015;30(1):3-23.

7. Kuhl S, Walter C, Acham S, Pfeffer R, Lambrecht JT. Bisphosphonate-related osteonecrosis of the jaws–a review. Oral Oncology. 2012;48(10):938-47.

8. Lee SH, Chang SS, Lee M, Chan RC, Lee CC. Risk of osteonecrosis in patients taking bisphosphonates for prevention of osteoporosis: a systematic review and meta-analysis. Osteoporosis International. 2014;25(3):1131-9.

9. Qi WX, Tang LN, He AN, Yao Y, Shen Z. Risk of osteonecrosis of the jaw in cancer patients receiving denosumab: a meta-analysis of seven randomized controlled trials. International Journal of Clinical Oncology. 2014;19(2):403-10.

10. Carmona EG, Flores AG, Santamaría EL, Olea AH, Lozano MPR. Systematic Literature Review of Biphosphonates and Osteonecrosis of the Jaw in Patients With Osteoporosis. Reumatologia Clinica. 2013;9(3):172-7.

11. Grbic JT, Black DM, Lyles KW, Reid DM, Orwoll E, McClung M, et al. The incidence of osteonecrosis of the jaw in patients receiving 5 milligrams of zoledronic acid: data from the health outcomes and reduced incidence with zoledronic acid once yearly clinical trials program. Journal of the American Dental Association. 2010;141(11):1365-70.

12. Hellstein JW, Adler RA, Edwards B, Jacobsen PL, Kalmar JR, Koka S, et al. Managing the care of patients receiving antiresorptive therapy for prevention and treatment of osteoporosis: executive summary of recommendations from the American Dental Association Council on Scientific Affairs. Journal of the American Dental Association. 2011;142(11):1243-51.

13. Lo JC, O’Ryan FS, Gordon NP, Yang J, Hui RL, Martin D, et al. Prevalence of osteonecrosis of the jaw in patients with oral bisphosphonate exposure. Journal of Oral and Maxillofacial Surgery. 2010;68(2):243-53.

14. Amgen Ltd. Prolia 60 mg solution in a pre-filled syringe: Summary of Product Characteristics 2016. Available from:
www.medicines.org.uk/emc/medicine/23127. Accessed 14/06/17.

15. Rogers SN, Palmer NO, Lowe D, Randall C. United Kingdom nationwide study of avascular necrosis of the jaws including bisphosphonate-related necrosis. The British Journal of Oral & Maxillofacial Surgery. 2015;53(2):176-82.

16. Sammut S, Malden N, Lopes V, Ralston S. Epidemiological study of alendronate-related osteonecrosis of the jaw in the southeast of Scotland. The British Journal of Oral & Maxillofacial Surgery. 2016;54(5):501-5.

17. Solomon DH, Mercer E, Woo SB, Avorn J, Schneeweiss S, Treister N. Defining the epidemiology of bisphosphonate-associated osteonecrosis of the jaw: prior work and current challenges. Osteoporosis International. 2013;24(1):237-44.

18. Gaudin E, Seidel L, Bacevic M, Rompen E, Lambert F. Occurrence and risk indicators of medication-related osteonecrosis of the jaw after dental extraction: a systematic review and meta-analysis. Journal of Clinical Periodontology. 2015;42(10):922-32.

19. Fehm T, Beck V, Banys M, Lipp HP, Hairass M, Reinert S, et al. Bisphosphonate-induced osteonecrosis of the jaw (ONJ): Incidence and risk factors in patients with breast cancer and gynecological malignancies. Gynecologic Oncology. 2009;112(3):605-9.

20. Saad F, Brown JE, Van Poznak C, Ibrahim T, Stemmer SM, Stopeck AT, et al. Incidence, risk factors, and outcomes of osteonecrosis of the jaw: integrated analysis from three blinded active-controlled phase III trials in cancer patients with bone metastases. Annals of Oncology. 2012;23(5):1341-7.

21. Vahtsevanos K, Kyrgidis A, Verrou E, Katodritou E, Triaridis S, Andreadis CG, et al. Longitudinal cohort study of risk factors in cancer patients of bisphosphonate-related osteonecrosis of the jaw. Journal of Clinical Oncology. 2009;27(32):5356-62.

22. Yazdi PM, Schiodt M. Dentoalveolar trauma and minor trauma as precipitating factors for medication-related osteonecrosis of the jaw (ONJ): a retrospective study of 149 consecutive patients from the Copenhagen ONJ Cohort. Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology. 2015;119(4):416-22.

23. Bone HG, Bolognese MA, Yuen CK, Kendler DL, Miller PD, Yang YC, et al. Effects of denosumab treatment and discontinuation on bone mineral density and bone turnover markers in postmenopausal women with low bone mass. The Journal of Clinical Endocrinology and Metabolism. 2011;96(4):972-80.

24. Nisi M, La Ferla F, Karapetsa D, Gennai S, Miccoli M, Baggiani A, et al. Risk factors influencing BRONJ staging in patients receiving intravenous bisphosphonates: a multivariate analysis. International Journal of Oral and Maxillofacial Surgery. 2015;44(5):586-91.

25. Otto S, Troltzsch M, Jambrovic V, Panya S, Probst F, Ristow O, et al. Tooth extraction in patients receiving oral or intravenous bisphosphonate administration: A trigger for BRONJ development? Journal of Cranio-maxillo-facial Surgery. 2015;43(6):847-54.

26. Taylor T, Bryant C, Popat S. A study of 225 patients on bisphosphonates presenting to the bisphosphonate clinic at King’s College Hospital. British Dental Journal. 2013;214(7):E18.

27. Tsao C, Darby I, Ebeling PR, Walsh K, O’Brien-Simpson N, Reynolds E, et al. Oral health risk factors for bisphosphonate-associated jaw osteonecrosis. Journal of Oral and Maxillofacial Surgery. 2013;71(8):1360-6.

28. Guarneri V, Miles D, Robert N, Dieras V, Glaspy J, Smith I, et al. Bevacizumab and osteonecrosis of the jaw: incidence and association with bisphosphonate therapy in three large prospective trials in advanced breast cancer. Breast Cancer Research and Treatment. 2010;122(1):181-8.

29. Ferlito S, Puzzo S, Liardo C. Preventive protocol for tooth extractions in patients treated with zoledronate: a case series. Journal of Oral and Maxillofacial Surgery. 2011;69(6):e1-4.

30. Lodi G, Sardella A, Salis A, Demarosi F, Tarozzi M, Carrassi A. Tooth extraction in patients taking intravenous bisphosphonates: a preventive protocol and case series. Journal of Oral and Maxillofacial Surgery. 2010;68(1):107-10.

31. Mozzati M, Arata V, Gallesio G. Tooth extraction in osteoporotic patients taking oral bisphosphonates. Osteoporosis International. 2013;24(5):1707-12.

32. Schubert M, Klatte I, Linek W, Muller B, Doring K, Eckelt U, et al. The saxon bisphosphonate register – therapy and prevention of bisphosphonate-related osteonecrosis of the jaws. Oral Oncology. 2012;48(4):349-54.

A visitor to the biennial International Dental Show (IDS) held in Cologne in March this year could have been mistaken for thinking that they were attending an engineering trade show rather than a dental event. The number of companies displaying milling machines, 3D printers, CAD-CAM hardware and software reflected the rapid developments in digital dentistry in recent years.

There is no area of dentistry that is not being ‘disrupted’ by the move from traditional analogue to digital practice, and implant dentistry is no exception. Planning software has been available for many years, but the recent addition of two concepts has seen a renewed interest in guided surgery. This article will examine optical scanning and desktop 3D printing in the production of drill guides, that may facilitate accurate surgical technique benefiting both the clinician and patient.

The aim of a detailed pre-surgical assessment is to ensure that the implant is placed in an optimal position so that it may be restored to achieve the desired aesthetic and functional result. Clinical and radiographic examination of the patient is required before implant placement. The assessment should consist of visual examination, palpation of superficial structures and the measurement of gap width, crest width and maxillo-mandibular relationships.

Radiographs are used during implant treatment planning and Cone beam computer tomography (CBCT) is used to view a 3D image of hard tissue. This enables the clinician to measure the height and width of the ridge and assess the quality of the planned implant site and adjacent anatomical structures. While there is still a place for conventional 2D imaging techniques, the use of a CBCT scan is now considered to be standard practice in implant dentistry1,2.

The images from CBCT scans may be imported into many software packages to allow the clinician to plan the implant placement in a virtual environment prior to surgery. Programmes such as Simplant (Dentsply Implants) have had the ability to not just plan implant placement, but to use CAD (computer aided design) output to CAM (computer aided manufacture) to produce drill guides for many years. Thus, it is important to state that neither the use of CBCT or guided surgery is new.

The use of guided surgery has previously been restricted by two factors:

  • Inability of CBCT to provide intra-oral soft tissue images
  • Cost of drill guide manufacture.

Intra-oral scanning provides detailed surface images of the dental hard and soft tissue. These images may be merged with hard-tissue images from a CBCT scan to provide a 3D view of teeth/bone and of soft issue. As with previous software, CAD planning allows the manufacture of drill guides. The availability of affordable 3D printers now allows the dentist to produce in-house accurate and cost-effective drill guides.

Both intra-oral scanning and 3D printing date back to the 1980s. Nearly 30 years later, both are changing the way we plan implant dentistry.

Optical intra-oral scanner
CEREC 1 was developed by Dr Werner H Mormann and Dr Marco Brandestini at the University of Zurich. Thanks to more powerful (and smaller) computers and the developing application of CAD/CAM systems at the time, their vision resulted in the first of the series of CEREC machines. From its early beginnings, limited to milling ceramic inlays, optical scanning and CAD/CAM manufacture are today at the focus of many developments in restorative and
surgical dentistry.

Optical scanners work by directing a light beam at an object, the light beam is bounced back to the scanner and the image is digitised. A digital image is a series of triangles joined together to make a 3D image – a meshwork of triangles – stored in digital format. 

STL (STereoLithography) is the file format of stereolithography CAD software that is widely used for rapid prototyping, 3D printing and computer-aided manufacturing. Images from dental optical scanners may output to STL files (open platform) or a scanner specific file format (closed platform). The two market-leading intra-oral scanners, Trios (3Shape, Denmark) and CEREC (Dentsply Sirona, Germany) have both recently enabled STL file output for their respective scanners. This move to STL open-platform enables dentists and dental labs to make use of the STL files in a wide range of software packages, rather than being restricted to a closed-platform programme.

In relation to implant planning software, the STL file is imported and combined with DICOM (Digital Imaging and Communication in Medicine) data from the CBCT scan (Fig 1). Many planning programmes are available – a selection is listed in Table one. A comparison of the strength and weaknesses of each is outwith the scope of this article but, as with any software, one should assess its ease of use, support, cost, open/closed platform.

The software allows the dentist to plan the implant position (Fig 2) and then design a drill guide (Fig 3). The design is outputted to an STL file, which can then be sent to a 3D printer either on-site or to a third party e.g. a dental lab.

3D printing
Early additive manufacturing equipment and materials were developed in the 1980s. 3D printing, also known as additive manufacturing or rapid prototyping, refers to processes used to create a three-dimensional object in which layers of material are formed under computer control to create an object. 3D printing builds a three-dimensional object from a CAD model by successively adding material layer by layer.

An early use of 3D printing in dentistry was shown in 1984 when a team working on sub-periosteal implants at Loma Linda University in California used 3D printing to produce a mandible from a CT scan3. The printed model of the mandible was then used to manufacture the sub-periosteal implant. The CT scan and 3D print removed the need for a surgical visit to take an impression of
the mandible.

The size and cost of 3D printers has fallen, while the range of 3D printers continues to grow at an astonishing pace. Originally aimed at industrial manufacturers, 3D printers are now available for all, from those aimed at the domestic hobbyist, to small and medium-sized business and large-scale operations.

In recent years, dental applications in desktop 3D printing have rapidly taken off. FormLabs (Massachusetts, US) products have been at the forefront of dental innovation. Aimed at the “prosumer” (production by consumer) market, dentists and dental labs now use the Form 2 (Fig 4) to create surgical guides, study models, bleaching trays, retainers, aligners, and with the imminent launch of FormLab denture resin, it will soon be possible to 3D print dentures. The Form 2 printer has a range of dental resins detailed in Table two.

The dental SG resin is an autoclavable, class 1 medical device directive registered biocompatible resin. Dental SG is used for printing surgical guides. It was launched by FormLabs in 2016 and was the first biocompatible resin for desktop 3D printing. Following 3D printing in the Form 2, dental SG is light cured in a light oven (Fig 5) (Brelux Power Unit 2, Bredent GmbH, Germany), the appropriate drill sleeve is selected and fitted for either a pilot of fully guided surgery (Fig 6). The drill guide may then be autoclaved prior to surgery.

Direct printing of surgical guides has traditionally required large-scale 3D printers that are beyond the expense of most dental laboratories and practices. The introduction of dental SG Resin and the Form 2 allows for surgical guide printing in dental practices and smaller dental labs.

Discussion
It has previously been possible to combine intra-oral detail with a CBCT scan without using an optical scanner. This was achieved using a dual scan technique, whereby a CBCT scan of a study model provided surface hard and soft tissue detail that could be merged with a CBCT scan. In edentulous cases where there is no intra oral hard tissue, it is not possible to use optical scans as intra-oral soft tissue cannot be linked to a CBCT scan. In such cases it is still necessary to use a dual scan technique with radiopaque markers in a denture. Thus, merging intra-oral and CBCT scans is restricted to dentate and partially edentulous cases.

The case for the use of drill guides is that they increase the accuracy of implant placement. Many studies have evaluated the accuracy of guided surgery4,5,6. There is a perception from the marketing of guided surgery by implant companies that this technique is easier than non-guided surgery. In many cases this may be correct, but it is essential that anyone undertaking guided surgery has a sound understanding of implant case planning and surgical protocols. The guide does not place the implant, the surgeon places the implant. The surgeon must be familiar with conventional approaches to implant placement and bone generation techniques before embarking on guided surgery.

It is important to state that guided surgery does not mean flapless surgery. 3D printed guides may be used for the following:

  • As pilot guides only with an appropriate muco-periosteal flap
  • Fully guided with an an appropriate muco-periosteal flap
  • Fully guided with a flap-less technique (Fig 7).

The surgical flap (or lack thereof) will be determined by the need for augmentation at the time of surgery. Flap-less surgery should be restricted to cases with ample bone volume and no need for either soft or hard tissue augmentation. Where there is any doubt with regard for the need for augmentation, an appropriately designed flap should be raised. Where suitable, the benefits of flap-less surgery with a drill guide include: reduced surgery time, minimal post operative complications, no sutures.

Drill sleeves for pilot guides will be determined by the diameter of the pilot drill, with a range of different sizes that are fitted to the guide following 3D printing. Drill sleeves for fully guided surgery are specific to the implant system being used. The surgeon should have additional training in the use of the guided surgical kit. This differs from the standard surgical kit in that each drill will have a stop to determine the depth of the osteotomy relative to the drill sleeve.

The drill is designed so that there is an offset between the drill sleeve and depth of the planned osteotomy (Fig 8). Inner sleeves or keys are used to match the diameter to the corresponding osteotomy drill (Fig 6). Each step of guided surgery is detailed on a drilling protocol supplied with the treatment plan.

The surgeon placing the dental implant is responsible for the implant placement, not the drill guide. The treatment plan for guided surgery must be approved by the implant dentist prior to 3D printing. When the dental surgeon is the dentist planning the guide, this is straightforward. In situations whereby the CBCT scan/implant planning is referred to a third party, then it is essential that there is effective communication between the parties and that the guided plan is approved by the referring dentist, who is ultimately responsible for the implant placement.

Clinical records including intra-oral images from an optical scanner, CBCT scan, treatment plan and drill guide demonstrate a high standard of planning and record keeping. Such documentation may be of benefit for medico-legal purposes. As with CBCT scans, it may be that this approach will become the gold standard of implant treatment planning and record keeping.

Conclusion
It seems that all of the pieces of the guided surgery jigsaw puzzle have now fallen into place: CBCT, optical scanning, CAD/CAM software and desktop 3D printing. Digital techniques, both hardware and software, are changing the way that dentistry is practised with benefits for both dentists and our patients. Implant companies are promoting guided surgery and it is essential that dentists are trained in such techniques and have a full understanding of the benefits and limitations of guided surgery. At the end of the day, computers and robots don’t place the implants… not yet, at least.

About the authors
Michael Dhesi is a GDP at Clyde Dental Centre. He qualified in 2012 with BDS(Hons) from the University of Glasgow and has subsequently completed MFDS RCPS(Glasg) and an MSc in Advanced General Dental Practice at the University of Birmingham. Michael’s focus is in minimally invasive and adhesive restorative dentistry.

He also has interests in the management of dental anxiety and oral surgery and welcomes referrals in these areas.

Clive Schmulian qualified from Glasgow University in 1993. Throughout his time in general dental practice, he has developed his clinical skills by obtaining a range of postgraduate qualifications, which in turn led him to develop an interest in digital imaging in both surgical and restorative dentistry. He is a director of Clyde Munro.

References
1. Bornstein MM, Scarfe WC, Vaughn VM, Jacobs R. Cone beam computed tomography in implant dentistry: a systematic review focusing on guidelines, indications, and radiation dose risks. Int J Oral Maxillofac Implants. 2014;29 Suppl:55-77.

2. Jacobs R, Quirynen M. Dental cone beam computed tomography: justification for use in planning oral implant placement. Periodontol 2000. 2014 Oct;66(1):203-13.

3. Truitt HP1, James R, Altman A, Boyne P. Use of computer tomography in subperiosteal implant therapy. J Prosthet Dent. 1988 Apr;59(4):474-7.

4. Raico Gallardo, da Silva-Olivio, Mukai, Morimoto, Sesma, Cordaro L. Accuracy comparison of guided surgery for dental implants according to the tissue of support: a systematic review and meta-analysis. Clin Oral Implants Res. 2017 May;28(5):602-612.

5. Ángeles Fernández-Gil, MD/Herminia Serrano Gil, MD/Miguel González Velasco, PhD/José C. Moreno Vázquez, MD, PhD. An In Vitro Model to Evaluate the Accuracy of Guided Implant Placement Based on the Surgeon’s Experience. JOMI. Volume 32, Issue 3 May/June 2017 Pages 515–524.

6. Corina Marilena Cristache, Silviu Gurbanescu. Accuracy Evaluation of a Stereolithographic Surgical Template for Dental Implant Insertion Using 3D Superimposition Protocol. Int J Dent. 2017; 2017.

The anatomy of the apical foramen changes with age as root formation has yet to be completed when teeth erupt. The completion of root development and closure of the apex occurs up to three years after eruption1.

Patients who present with immature apical formation (see Fig 1) pose a challenge due to the presence of large open apices along with divergent and thin dentinal walls that are susceptible to fracture. Historically, we have tried to generate formation of an apical barrier by repeated placement of calcium hydroxide over many months, or more recently by immediate barrier formation with a Mineral Trioxide Aggregate (MTA) plug.

Ideal management would involve regeneration of new pulpal tissue and continued root formation. Novel techniques for dealing with immature apices such as apexogenesis sometimes claim to be regenerative techniques. However, assessment of the composition of this regenerated tissue has proven to be difficult and it seems that it is made up of periodontal and bone tissue rather than tissue of pulpal origin2. As clinicians we need to consider whether this is better than formation of an apical barrier and obturation by conventional means?

Root development (see Table 1)
Classically, there are two types of open apices; blunderbuss and non-blunderbuss. In the former, the walls of the canal are divergent and flaring, the apex is funnel shaped and typically wider than the coronal aspect of the canal. In a non-blunderbuss apex, the walls of the canal may be parallel to slightly convergent. The apex, therefore can be broad shaped or convergent.

What are the causes of open apices?
Incomplete root development often arises secondary to pulpal necrosis arising as a result of caries or trauma. Both foraminal and peri-foraminal resorption of the root end may also arise in the presence of a periapical lesion4. This may alter the anatomy of a pre-existing open apex further. Iatrogenic enlargement of the root end may also arise due to poor control of working length and subsequent enlargement with both hand and rotary files.

What problems are faced clinically?
Teeth with open apices often tend to have thin dentinal walls that are susceptible to fracture before, during or after endodontic treatment. Frequently, they present with periapical lesions, which may or may not be associated with apical resorption. Short roots compromise the crown-root ratio, often affecting long-term prognosis.

Fractures of the crown are common following trauma. This can compromise aesthetics, especially in the anterior region, and there may be a lack of tooth tissue present. In long-standing cases these teeth may also undergo discolouration. Large open apices pose a challenge in determining the working length, decision on the necessity of root canal preparation, and achieving control
during obturation.

How is the working length determined?
There is relatively little data regarding the value of radiography and electronic apex locator (EAL) use when root formation is incomplete, and supplementary measurement techniques may be helpful. When using an EAL to measure working length in such cases, it is essential to use a file which is well matched to the apical size (see Fig 2) where possible. The paper point technique described by Rosenberg to supplement initial apex locator readings could be considered for the working length determination of open apices in relatively straight canals5.

Marcos-Arenal et al.6 in an in vivo study, demonstrated an 87 per cent accuracy of this technique in establishing working length to within 0.5mm of the apical foramen. While El Ayouti et al.7 proposed a tactile method involving the use of a size 25 K-file bent at the tip, with its orientation marked with a silicone ring. The file was bent to facilitate ease of use. In this study, 95 per cent of cases were accurate to within 0.5mm of the apical foramen.

Do I need to instrument the canal?
During conventional root canal treatment, the role of instrumentation is to achieve removal of vital and necrotic tissues from the root canal system, along with infected root dentine8. It aims to prepare the canal space to facilitate attempts at disinfection using irrigants and medicaments. As a result, minimal instrumentation of teeth with open apices (and thin dentinal walls) is needed due to the ease in placement of irrigation devices close to the working length.

How do I obturate the canal?
The options for obturation are dependent on whether or not we aim to create an apical barrier. Figure 3 highlights the different options. Apexification and apexogenesis are two endodontic procedures which attempt to either induce apical repair by initiating a hard tissue barrier across an open apex or to promote the continued formation of the apical portion of the root9.

Apexification
Calcium Hydroxide has been the first choice material for apexification. Placement and repeated changes over the course of five to 20 months induces the formation of a calcific barrier. The unpredictable and lengthy course of treatment presented challenges, particularly as it required a high level of patient compliance. For this reason, one visit apexification has been suggested.

MTA has been proposed as a material suitable for one visit apexification as it combines a bacteriostatic action, biocompatibility and a favourable sealing ability. Placement of a 3mm thickness of MTA in the apical portion of an ‘open apex’ permits the vertical condensation of warm gutta percha into the remainder of the canal (See Fig 4).

Apexogenesis
Case reports in the literature over the past 10 years have demonstrated successful revascularisation and regeneration of immature permanent teeth with apical periodontitis. Banchs and Trope10 irrigated necrotic teeth with sodium hypochlorite, and placed an antibiotic tri-paste dressing consisting of metronidazole, minocycline and ciprofloxacin. Four weeks later, the tooth was re-accessed and bleeding encouraged at the apex, allowing a clot to form 3mm below the CEJ. MTA was placed on the blood clot and the tooth restored with composite. Follow-up radiographs demonstrated complete apical healing and continued root formation.

Shin et al.11 treated a non-vital mandibular second premolar tooth using irrigation with 6 per cent sodium hypochlorite and 2 per cent chlorhexidine without instrumentation in a single visit. The successful outcome of this case report suggests that this conservative revascularisation treatment approach can create a suitable environment for pulpal repair, resulting in the completion of root maturation.

McCabe12 recently published a case report showing disinfection with 5 per cent sodium hypochlorite followed by the induction of a blood clot into the root canal space may be sufficient to promote revascularisation in certain circumstances using a single visit protocol.

Most of the case reports regarding apexogenesis as a treatment modality have shown an increase in dentinal wall thickening and root length, with a reduction in the volume of the pulp canal space visible radiographically. Histological analysis of teeth which had undergone revascularisation treatment demonstrated that the mineralised layer on the walls which was present appeared to be of periodontal origin rather than pulpal origin12.

What does the future hold?
It appears that current treatment approaches tend to stimulate reparative rather than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp complex. Although patients requiring treatment undoubtedly make up a small proportion of our patients, and despite the biological limitations, such techniques appear to offer significant promise for improved treatment outcomes2.

The main question is whether our patients are better served by apexification and formation of an apical barrier via an MTA plug, or whether apexogenesis and generation of reparative tissue within the canal space, even if it is periodontal in origin, is better? It could be argued that apexogenesis will make the tooth more suitable for restoration, as teeth which have undergone apexification tend to be more fragile and prone to cervical fractures.

Any attempt to undergo biological healing should prove to be more beneficial in the long term. Further research is required into this novel approach to apexogenesis to assess the long-term prognosis of these teeth. Current research on pulp regeneration is growing and provides exciting possibilities for greater biological approaches to endodontics in the future13.

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A rapidly growing intraoral lesion