A new patient in her early 30s attended for a check-up. A routine radiograph revealed caries under the amalgam filling on the upper right second premolar (UR5). When advised the tooth needed treatment, the patient revealed she had been unhappy with how it looked. The filling was very visible and shiny when she smiled. The dark appearance of the tooth also made her self-conscious. The patient had thought treatment would be long and expensive, so she hadn’t bothered to ask.

The options were to have another amalgam filling or a composite restoration. The patient was advised that further composite treatment could be needed buccally to mask any remaining grey discolouration, if she was not satisfied with the outcome. As she was concerned about the appearance of the tooth, the patient did not want an amalgam filling and decided to have the composite restoration.

 

Preparation

After a local anaesthetic was given, rubber dam was placed, with a clamp on the UR6, exposing the UR 4, 5 and 6. This was secured in place with floss ties. The old amalgam and caries were removed. The final portion of discoloured dentine was left behind as it was very deep, but the pulp was not exposed and it was still firm.

A sectional matrix band was then positioned mesially on the UR5, with a wedge and separation ring (V-ring). Initially, the enamel periphery alone was etched with 37 per cent phosphoric acid for 15 seconds. Etch was applied to the rest of the cavity for a further 15 seconds, before rinsing. A cotton pledget was used to protect the dentine during the drying process, to ensure dry enamel and moist dentine.

A two-bottle adhesive, with separate primer and adhesive, was used to complete the preparation. The dentine was primed and left for 30 seconds. The adhesive was placed on both the enamel and dentine, and allowed to sit for
30 seconds before curing.

 

Restoration

In this case, Venus Pearl composite was used. This material exhibits good levels of opacity to block out discolouration and excellent handling for posteriors, making it a very easy-to-use product.

In this restoration, a small amount of Venus Flow base liner was placed and cured. This was to mask the greyness and dark discolouration from the base of the cavity. Next a thin layer of Venus Pearl A2 shade was applied to build up the mesial wall against the matrix. The height was built up to the level of the adjacent marginal ridge. The material was then manipulated with a sharp probe at a 45 degree angle. This ensured the edge of the wall was not straight and the natural curved shape of the marginal ridge was maintained. The dentine mass was built up in increments with Venus Pearl ODC shade.

Enamel A2 shade was placed over the occlusal surfaces cusp by cusp. Complete separation of the masses was achieved by creating fissures down to the dentine layer, using a sharp probe. Secondary anatomy was manipulated into the unset material before light curing.

A mix of Venus Color ‘corn’ and ‘choco’ stains was applied to the fissures using a probe, and pressed in with a long- bristle brush. The excess was wiped away with a conventional micro-brush and the stain was cured. Highlights were placed on the ridges using Venus Color ‘white’ mixed with a little ‘corn’, to give a milky colour. Final adjustments were carried out before rough, dry polishing. The restoration was then sealed with a protective clear coating, covered with glycerine and cured.

 

Outcome

In this case, the clinical outcome was good. The tooth is regularly monitored for vitality and the patient has had no problems with it. As the caries was so deep, in the long term the tooth may require root canal treatment, but it is currently sound. The patient was delighted with the result after having endured an unsightly amalgam filling for years.

FIGURE 1: A routine X-ray revealed caries under the amalgam filling in the upper right 5

 

FIGURE 2: The UR5 filling was very visible when she smiled and the dark appearance made her self-conscious

 

FIGURE 3: The old amalgam and caries were removed following rubber dam placement

 

 

FIGURE 4: Kulzer Venus Pearl A2 shade was applied to build up the mesial wall

 


FIGURE 5: Separation of the masses was achieved by creating fissures down to the dentine layer and then stain was applied

 

FIGURE 6: The patient was delighted with the result after having endured an unsightly amalgam filling for years

 


 

About the author

Dr Monik Vasant BChD MSc is a highly experienced clinician with a special interest in minimally invasive aesthetic dentistry. He has trained under many of the world’s leading clinicians and has an MSc in aesthetic and restorative dentistry.

He is the director of Freshdental,with sites in Central London and Greater Manchester.

Monik lectures globally on minimally invasive and adhesive dentistry. His highly regarded direct composite course “Totally composite” is held throughout the UK and internationally.  He also runs a year long minimally invasive aesthetic dentistry course entitled ‘Totally Aesthetics’.

Monik is a global key opinion leader for several dental companies and has co-authored several books on various aspects of general practice.

Contact monik@freshdental.co.uk or for course information and bookings, visit www.monikvasant.co.uk

Follow Monik on Instagram @drmonik

 


 

Monik is the keynote speaker at the Scottish Dental Show 2018, to be held at Braehead Arena on 27 and 28 April. He will be presenting two lectures on Friday 27 April, ‘Composite artistry’ and ‘Composites and digital dentistry’.

To find out more and to register for your FREE delegate pass that will get you access to 140 exhibition stands and more than 50 lecture and workshops sessions, with up to NINE hours of vCPD, visit www.sdshow.co.uk

 

Mrs M attends her dentist, Mr A, complaining of pain in an upper tooth. They discuss treatment options and she agrees to undergo private treatment, including root filling and the fitting of a new crown. She signs a treatment plan which shows the cost of the work will amount to around £500.

The treatment is carried out without incident and Mrs M pays part of the bill before leaving that day. The practice sends out an account detailing the remaining total but, three months later, no further payments have been made. Mr A issues another written account to Mrs M but is then contacted by Mr M who says he is assuming responsibility, with his wife’s consent, for the bill. He asks why the cost is so high but Mr A explains the treatment given and that the price was agreed in advance.

Five months after the initial appointment, still no further payment has been made. Mr A phones Mr M at home to discuss the matter. There is no answer but the phone switches to an answering machine, identified as belonging to Mr and Mrs M. He leaves a message asking Mr M to contact the practice about the unpaid bill.

One week later, Mr A receives a cheque for £150 from Mr M along with a promise that more money will follow soon. It is also accompanied by a letter of complaint from Mr M who is angry that the dentist disclosed information about the unpaid bill in the answering machine message. His daughter had dropped by while he was out and heard it, causing him considerable embarrassment.

Mr A sends a written apology to Mr M and agrees to let him pay the bill off over the next two months.

A short time later, however, Mr A is notified by the General Dental Council that a complaint has been made against him alleging a breach of confidentiality and claiming the cost of treatment was unfair and had not been
clearly discussed.

Analysis/outcome

Mr A calls MDDUS for advice. It is recommended he writes a further letter of apology to Mr M. Mr A accepts that sensitive information about the unpaid bill should not have been disclosed in the phone message and that practice procedures have been changed to avoid a repeat of this error. It is also advised that Mr A waives the outstanding sum owed to the practice in recognition of the distress caused by the confidentiality breach.

Regarding the disputed fee, Mr A is confident that this was fully discussed with the patient in advance and he has the treatment plan signed by Mrs M to support this.

The GDC case is eventually closed with no action taken against Mr A.

Key points

  • Never disclose sensitive patient information in telephone messages
  • Be aware of the potential for third parties to intercept messages, even on personal mobile phones
  • Always ensure costs are discussed and agreed upon, in writing, before treatment is carried out.

 


 

About the author

Aubrey Craig is head of dental division at MDDUS. For more information, go to www.mddus.com

Imaging is essential in endodontics. Traditionally, X-rays (radiographs) have been used and more recently cone beam computed tomography (CBCT) is used to give the clinician more detailed tooth information as part of a clinical examination.

Radiographs have been an invaluable tool in the dentist’s armamentarium in the diagnosis and management of dental problems, (Grondahl and Huumonen, 2004), since their introduction in 1865. Radiographs may be taken as single parallel images or two images applying the parallax technique. Radiographs fundamentally represent a two-dimensional representation of a three-dimensional spatial relationship. The shortcomings and limitations of radiographs are; a degree of magnification – 5 per cent or more (Voorde and Bjorndahl, 1969), superimposition, geometric distortion and lack standardization or reproducibility.

Aria et al 1999 and Mozzo et al, 1998 independently developed a new tomographic scanner known as CBCT and this was specifically for maxillofacial and dental use. CBCT (Fig 1) is a modern three-dimensional imaging system which produces high-quality images using relatively low doses of radiation (see Table 1).

TABLE 1: Comparisons of scans reproduced from Essentials of Dental Radiography and Radiology, 4th edition 2007

 

CBCT differs from ‘medical’ multi-slice CT (MSCT), as the whole volume of data is acquired in a single sweep with rotations varying between 180-360 degrees. The scanning time is reduced, typically 10-20 seconds, and radiation dose to the patient is less since the cone shaped (not fan shaped as MSCT) beam is pulsed, reducing exposure times to only 3.5 seconds. Approximately 580 images are produced and the field of view (FOV) can be as small as 40mm x 40mm, which can be useful in endodontics (SEDENTEXCT 2012) (Fig 2).

FIG 1: An Accuitomo small volume CBCT scanning machine (Image reproduced from J.Morita USA Inc)

 

Application of CBCT in endodontics

Limited volume (small FOV) CBCT scanners capture small volumes of data that can include just two or three individual teeth. CBCT allows the operator to view data in three planes: sagittal, axial and coronal (Fig 3). As all the information is obtained in a single rotation, it is very important that the patient is stationary throughout the exposure.

Spatial resolution is a drawback with CBCT since there is only approximately a tenth of the resolution that is currently available with digital and conventional radiographic films. “Increased resolution usually comes at the expense of an increased dose to the patient, as a result of longer exposure times to acquire more 2D projections to a more detailed reconstruction,” (Christiansen et al 2009).

Another limitation of CBCT scans are their vulnerability to beam hardening and streak artefact, which can reduce the image quality even further by producing dark bands or streaks in the image.

FIG 2: Basic concept of CBCT

 

FIG 3: CBCT image planes

 

Notwithstanding the above limitations, there are a number of applications for CBCT in endodontics which may overcome the limitations of conventional and digital radiographs and ultimately improve patient management. CBCT with a limited FOV may be considered in the below situations as recommended by the European Society of Endodontology (ESE) position statement 2014:

The use of CBCT in endodontics:

  1. Diagnosis of radiographic signs of periapical pathosis when there are contradictory (non-specific) signs and/
    or symptoms
  2. Confirmation of non-odontogenic causes of pathosis
  3. Assessment and/or management of complex dento-alveolar trauma, which may not be readily evaluated form conventional radiographic views
  4. Appreciation of extremely complex root canal systems prior to endodontic management
  5. Assessment of extremely complex root canal anatomy in teeth planned for non-surgical endodontic re-treatment
  6. Assessment of endodontic treatment complications (for example, [post] perforations) for treatment planning purposes when existing conventional radiographic views have yielded insufficient information
  7. Assessment and/or management of root resorption
  8. Pre-surgical assessment prior to complex peri-radicular surgery.

As stated by Rosen et al 2015: “A web-based survey emailed to 3,844 active members of the American Association of Endodontists in the United States and Canada reported a significant increase in the use of cone-beam computed tomographic (CBCT) imaging; 34.2 per cent of 1,369 respondents indicated that they were using CBCT imaging for diagnosis and treatment planning purposes,” (Dailey et al 2010).

 

Implications of CBCT in endodontics

There are a number of implications of CBCT in its application in endodontics, some of which have been discussed earlier, such as radiation dose and treatment outcome.

CBCT still uses ionising radiation and is not without risk. Radiation dose and ‘stochastic effects’ are important considerations. As discussed earlier, CBCT does expose patients to an increased radiation dosage. The principles of ‘As Low As Reasonably Achievable’ (ALARA) should always be applied to limit patient dose.

Every radiation exposure a patient has must be justified and optimised ideally with strict selection criteria as stated by the FGDP guidelines, 2013. The FOV must be reported on in its entirety since the clinician has a legal obligation to read and comment on the whole view. This highlights the training the operator must undergo before taking scans and the clinician must engage the advice of a suitably qualified radiologist if further advice/information is sought (Brown et al 2014).

The cost of CBCT scanners must not be allowed to motivate clinicians to take scans without first justifying the exposure. Ethical scanning is paramount.

Another implication may be the potential removal of metallic coronal restorations to avoid ‘beam hardening’, which would increase procedural time and patient cost.

Wu et al 2009 recommended that: “The outcome of root canal treatment should be re-evaluated in the long term using CBCT and stricter evaluation criteria”, for the reasons as discussed earlier. This has led many researchers to argue and debate a very crucial question: What constitutes endodontic success? An asymptomatic patient or a ‘healed’ scan or periapical?

“This has a huge implication on clinical decision making and selection criteria when considering (re-) placing coronal restorations on teeth which have previously been endodontically treated and appear to have successfully healed on the radiograph,” (FGDP 2013).

Some have asked for more clarification from the European Society of Endoontology (ESE), which has recently published a position statement: ‘The use of CBCT in Endodontics’, in 2014. The guidelines advise that “every image involving ionizing radiation, including CBCT, must be justified and optimised. A record of the justification process must
be maintained.”

“Clinical studies with a primary outcome measure of detecting the presence or absence of apical periodontitis and epidemiological studies assessing the prevalence of apical periodontitis in different populations may have to be re-evaluated,” (Ng 2010).

The question, therefore, may be posed as to how much relevance a CBCT has in clinical decision-making in endodontics? If a clinician has not obtained enough relevant information from a radiograph and has made the clinical judgement to expose the patient to a CBCT scan, does the information provided by the CBCT image have an effect on the clinician’s clinical management of that patient? Does the exposure of the patient to a CBCT image have a net positive benefit to the patient? Is this justified following the guidelines discussed earlier?

The scoping searches showed a number of papers important to this review in the existing literature:

  • Balasundaram et al 2012. Comparison of Cone-Beam Computed Tomography and Periapical Radiography in Predicting Treatment Decision for Periapical Lesions: A Clinical Study.
  • Cheung et al 2013. Agreement between periapical radiographs and cone-beam computed tomography for assessment of periapical status of root filled molar teeth.
  • Mota de Almeida et al 2014. The impact of CBCT on the choice of endodontic diagnosis.
  • Estrela et al 2014. Characterization of successful root canal treatment.
  • Mota de Almeida et al 2014. The effect of CBCT on therapeutic decision-making in endodontics.
  • Rosen et al 2015. The diagnostic efficacy of CBCT in endodontics: A systematic review and analysis by a Hierarchical Model of Efficacy.
  • Ee et al 2014. Comparison of endodontic diagnosis and treatment planning decisions using CBCT vs periapical rads.
  • Hashem et al 2015. Clinical and radiographic assessment of the efficacy of calcium silicate indirect pulp capping: a randomised controlled clinical trial.
  • SEDENTEXCT Project. Radiation Protection 172. Evidence-Based Guidelines on Cone Beam CT for Dental and Maxillofacial Radiology [Internet]. 2011 [cited 2012 Dec 10]. Available at: http://www.sedentexct.eu/content/guidelines-cbctdental-and-maxillofacial-radiology. Accessed August 6, 2012.

Scoping searches to formulate an idea of the current state of knowledge of the topic literature showed limited studies in this area. Studies that were found appear mainly to be in-vitro with few in vivo studies. This, of course, highlights the justification of performing in vivo studies in humans where ethical issues are paramount in the 21st century. Scoping searches were performed using the PROSPERO, PubMed and Google Scholar databases. Scoping searches also identified a number of well-published authors who appear to be leaders in the field of CBCT: S Patel, C Durack, F Abella, M Roig, H Shemesh, P Lambrechts and K Lemberg.

CBCT can overcome some of the limitations of intra-oral radiographs, which are the primary imaging method in endodontics (Lofthag-Hansen et al, 2007 and Scarfe et al, 2009).Therefore, the usefulness of CBCT imaging can no longer be disputed, since they can complement radiographs. It is an important imaging tool in contemporary endodontics and “has been shown to be superior to conventional periapical and panoramic radiography in its accuracy and sensitivity in detecting endodontic related pathology” (Stavropoulos and Wenzel, 2007, Tsai et al, 2012, Liang et al, 2014).

As scanners become more affordable and radiation dose to the patient possibly reducing, more endodontic disease may be detected in the future, which inevitably means better patient management. However, Pope et al 2014 have discussed that more sensitive technology may cause over-diagnosis, which could potentially harm
healthy patients.

Presently, academic opinion (ESE position statement, 2014) advises that “CBCT should only be considered in situations where diagnostic information from clinical examination and conventional radiographs does not yield an adequate amount of information to allow appropriate management of the patient. A case-by-case approach is recommended and a CBCT scan should have a net benefit to the management of a patient’s endodontic problem”.

 

Clinical decision-making in endodontics

Clinical decision-making in endodontics is a process which involves the clinician’s diagnostic skills and the patient’s presenting signs and symptoms. It is a conclusion reached only after assessment of signs, symptoms, examination, special tests, consideration of expected outcome and, most importantly, the patient’s wishes. Therefore, “decision-making depends on the skill and experience of the clinician and the treatment options available which is termed as evidence-based practice” (Sackett et al, 1996).

However, “the needs and preferences of the patient are what drives the treatment decision since only the patient is truly the expert as to how he/she feels about maintaining a tooth, what symptoms are tolerable, what risks are worth taking and of course what costs are acceptable” (Bergenholtz and Kvist, 2014). Therefore, a patient-centred outcome is ideal. “Diagnosis is seen as only one part of the medical decision process” (Ledley and Lusted, 1959). Once a clinical decision has been reached, only then should treatment be executed with the patient’s informed consent.

TABLE 2:  A Hierarchical Model of Efficacy: Typical Measures of Analysis (Fryback and Thornbury 1991)

 

Radiographs have been used as an imaging tool to base clinical decisions on and Strindberg developed a system in 1956. His system was based on biology and can be perceived as being dogmatic and inflexible. In the Strindberg system, a normal periradicular situation on periapical image with no patient symptoms was identified as endodontic success and a periradicular lesion apparent on a periapical radiograph was identified as endodontic failure. This has been discussed by Kvist 1994 and in a series of papers (Papers I-V, 1998, 1999 and 2000) where he proposed an alternative theory based on Praxis Concept (Jensen 1985). Praxis, which is Greek for process, is the process by which a theory or skill is enacted, embodied or realised. This theory states that personal values influence endodontic treatment and that clinicians use ‘cut-off’ points in their decision-making process.

Fryback and Thornbury (1991) have discussed the assessment of the contribution of diagnostic imaging to the patient management process in their seminal paper, The Efficacy of Diagnostic Imaging. In their study, they propose a ‘Hierarchical Model of Efficacy’, which is an organising structure for appraisal of the literature on the efficacy of imaging. There are six levels as listed in Figure 4:

  1. Technical quality of image
  2. Diagnostic accuracy, sensitivity and specificity of image interpretation
  3. Change in clinician’s diagnostic thinking?
  4. Effect on patient management
  5. Effect on patient outcomes
  6. Societal costs and benefits of a diagnostic imaging technology.

 

According to Fryback and Thornbury (1991), with level three “the imaging information may change the differential diagnosis, strengthen an existing hypothesis, or simply reassure the physician”. With level four, ‘Therapeutic Efficacy’, “an imaging examination result may influence the physician’s diagnostic thinking and yet have no impact on patient treatment”. With level five, ‘Patient Outcome Efficacy’, “is concerned with whether there is measurable effect of the image on the outcome experienced by the patient” since the ultimate goal of dental care is to improve, or return to normal, the health of the patient.

Therefore, this structured critical review will focus on levels three, four and five in the ‘Hierarchical Model’ (Table 2) since the question posed is the use of an imaging modality (CBCT) and how it influences clinical decision-making in endodontics.

So, with regards to the use of CBCT in clinical decision-making in endodontics, what does the current literature say? Evidence appears to be sparse. Mota de Almeida et al (2014) have concluded that “CBCT has a substantial impact on diagnostic thinking in endodontics when used in accordance with the European Commission guidelines”. In their clinical study, Balsundaram et al (2012) concluded that “Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2D radiographs”. Cheung et al (2013), concluded that “there were substantial disagreements between PA and CBCT for assessing the periapical status of molar teeth, especially for the maxillary arch”.

It is clear that there is not an agreement of opinion and whether there is a clear benefit to the clinician and to the patient in taking a CBCT scan. An investigation of available evidence as it relates to levels three, four and five, may clarify the role of CBCT in endodontic decision-making.

The research question for this study: Does CBCT influence clinical decision making in endodontics?, arose from the author’s interest in the imaging modalities used in endodontics. In the author’s almost 20 years clinical experience, it has been noted that many Scottish patients wish to keep their teeth and avoid extractions. People’s attitudes to dentistry, which may be media and culturally led, appear to be changing. The limitations within the National Health Service (NHS) in Scotland, may have led patients to look at private options to restore their teeth with a view to avoiding costly dental implants.

In the author’s opinion, root canal treatments are being considered more by patients, not only on the NHS but also privately. The author has found that since patient expectations are sometimes high, the diagnostic process must give the clinician and patient as much information as possible so the patient is able to make the correct informed decision. CBCT may offer more information, as discussed earlier, but does this information make a difference in the decision-making process? CBCT, being a relatively new and exciting diagnostic tool in endodontics, is used by some general dental practitioners and specialists in the UK but its use should be only when radiographs do not prove diagnostically beneficial. The question arises, when is this?

As discussed earlier, ESE guidelines are quite specific. CBCT should not be taken routinely in the diagnostic process but only when there is a net benefit to the patient. Clinically, a patient may present to a clinician with symptoms which cannot be diagnosed either upon clinical examination or with a radiograph. In this scenario is a CBCT useful?

The aim of this study is to perform a structured critical review on the current published research and to draw a conclusion as to the influence of CBCT in clinical decision making in endodontics.

The objectives of this review are based on nine basic steps, as suggested by Boland et al (2014):

  1. Performing scoping searches, identifying the review question and writing the protocol
  2. Literature searching including the search strategy
  3. Screening titles and abstracts
  4. Obtaining papers
  5. Selecting full-text papers
  6. Quality assessment
  7. Data extraction
  8. Analysis and synthesis
  9. Writing up and editing.

 


 

About the author

Arvind Sharma, BDS(Dund), MSc(Endo), MJDFRCS(Eng), MFDSRCPS(Glas), work in practice limited to endodontics and takes referrals at New Life Teeth in Edinburgh and Philip Friel Advanced Dentistry in Glasgow.

This article is based on the submitted dissertation in partial fulfilment of the requirements for the Degree of Master of Science in Endodontology, 2016. The author appreciates that much of the in-depth analysis has been omitted for the purposes of the current publication and readers are welcome to contact the author for more detail if they so wish – visit asendodontics.com for info.

References will be provided in full in the second part of the article, which will be published in the next issue of Scottish Dental.

 

This article is the first in a series that aims to introduce the modern-day dental practitioner to evidence-based dentistry (EBD). After reading this series, you will be clearer about how to keep abreast of the ever-growing evidence base and the latest guidance. You will know where to look for evidence and learn how to maximise time spent searching for evidence to inform your practice.

In our day-to-day lives, we have become accustomed to using search engines such a Bing or Google to help answer simple questions, but, when it comes to our clinical work and professional life, we need to take a more formal approach in our search. There are a number of web-based scientific databases that catalogue evidence. The databases can be thought of as massive online libraries, but like any library, if you don’t know your way around it or the cataloguing system used, then you are likely to get lost and spend hours searching for what you need. Therefore, having an awareness of the different scientific databases available and understanding how to use them is a good starting point.

An example of a well-known database, and one you may have already used is PubMed. Simply typing the word ‘dental’ into the search box on PubMed results in more than half a million hits – 516,870 to be precise. These 516,000 hits are spread over 25,844 pages, which makes for a lot of reading. Clearly, we need a more focused approach. So, what then if we pick a subject within dentistry such as fluoride varnish? This search still returns 1,293 hits spread over 65 pages.

The point we are demonstrating here is that there is a wealth of information and publications that we can make use of, but there is some skill required to negotiate databases and identify quality evidence. A busy practitioner needs access to high-quality evidence quickly and easily.

Evidence-based dentistry

The American Dental Association describe EBD as “an approach to oral healthcare that requires the judicious integration of systematic assessments of clinically relevant scientific evidence, relating to the patient’s oral and medical condition and history, with the dentist’s clinical expertise and the patient’s treatment needs and preferences.”[1]

As dentists we want to do our best for each and every patient we treat, and this is at the heart of EBD. Most dentists will be confident in their clinical skills and will listen to patients but not all will be confident in the strength of evidence behind how and what they practice. The evidence should be a constant go to for a modern-day dentist.

Developing an evidence-based approach can be thought of in five stages:

  1. Asking the right question
  2. Searching for the best available evidence
  3. Critically appraising the evidence
  4. Applying the evidence
  5. Evaluating the outcome.

In your life outside of the surgery, you will already be using this approach, whether you realise it or not. Take buying a new car, for example. Let’s say it is a used car; you may not want to rely solely on the sales person’s word that the shiny car on the forecourt really is the best one for you. You will need to think about what it is you really need from the car – is a sporty convertible with two seats and no boot space going to suit your lifestyle? Maybe it is.

Most people will search the internet comparing various cars on independent websites; they will look in magazines or speak to friends and family beforehand. So, when you arrive at the showroom you already have an idea of what you are looking for and what you need from a car. At this point, you have carried out the first stage of an evidence-based approach: Asking the right question. You have also begun the second stage: Searching for the best available evidence.

When you have identified a potential car, you will want to continue your search for evidence to support your decision to buy. You will want to know more details about the service history, you might inspect the paintwork, check how many miles it has done and ask about previous owners. You will combine this information with what you found out previously and check the quality of the evidence before you. This is stage three: Critically appraising the evidence.

Next comes the big decision; whether to go ahead with the purchase. After carefully considering all the evidence you have available, you may or may not decide to buy the car, this is stage four: Applying the evidence.

The final stage is evaluating the outcome. This will take place in the months and years to come when you will be driving the car. If the car keeps breaking down and needs multiple new parts, you might question your approach and the evidence upon which you based your decision.

In this article we will cover stages one and two of the evidence-based approach.

Figure 1: Hierarchy of evidence [2]

Asking the right question

Evidence-based dentistry starts with a clinical question. You need to be clear about what it is you are trying to find evidence for. A good technique to help develop your question is to use PICO.

What is PICO?

PICO is an acronym for Population, Intervention, Comparator and Outcome. It is used when developing a question regarding a clinical scenario. Say, for example, you are a general dental practitioner; you suggest that the five-year-old patient in your chair should have fluoride varnish applied to her teeth. The patient’s parent questions this; he asks you “what good will it do?”, and at this point, he does not provide consent.

Using the PICO approach, we can build our question and start our search for the evidence. First of all, we need to establish the key population group that we want to find evidence about. In this case, it is children.

Next, we need to think about what treatment we are proposing and what the alternative might be. Here, we are proposing fluoride varnish application and the comparison would be no fluoride varnish. You could also choose an active treatment for comparison, such as fluoride mouthwash or toothpaste. Having an alternative prevention option might help win over the parent in this scenario.

Having a clear idea about what outcome you want from the treatment is important. Here, our key outcome is the caries rate in the child.

As a result of this process, we now have a PICO question we can use in a database search:

  • Population, patient or problem: Children
  • Intervention or treatment: Fluoride varnish
  • Comparison: No treatment
  • Outcome: Caries.

Searching for the best available evidence (AQUIRE)

We now have a clear PICO question for moving forward with and have completed stage one. In the next stage, we need to think about the types of evidence there are and where we can find them.

This section will aid you in the search for the best available evidence. It has two parts. In the first part we will explore the hierarchy of evidence and the uses for each type, while the second part published in the next article, will take you through the practicalities of different databases.

Types of evidence

First let us think about the different types and levels of evidence available. The most common and easy way to think about evidence is as a pyramid or hierarchy as shown in Figure 1 on the previous page.

It is quite intuitive, with the highest levels of evidence found at the top of the pyramid. Each type of evidence has a role to play in shaping healthcare. We will work our way up the pyramid discussing each of the types of evidence in turn while exploring the pros and cons of each.

In vitro/animal research

Animal and in vitro research can be useful in the initial stages of developing treatment, for example when exploring causes behind disease or investigating an early idea or hypothesis.

The dental materials we use are initially tested in the lab. If they fail at this stage then there would be no point in testing the material in humans without overcoming the initial flaws identified.

With animal experiments there can be an issue when it comes to translating or replicating findings in humans. Some treatments may never work or they may actually be harmful to humans. The process of getting from the lab bench to chair side can take decades of refinement.

In this article, our focus is on what works best in the clinical situation and therefore this type of lab-based study is not immediately transferable into practice.

Ideas, editorials and opinions

Initially, most people think their own ideas are great but do they stand up to the scrutiny of others? As we mentioned above, ideas need testing. Personal opinions and written editorials often only provide one view point. Therefore, it would not be a good idea to change your practice based on a discussion over a cup of coffee or on a single editorial on a website, magazine or journal.

There are occasions when a combined opinion can be useful though. Sometimes professional groups come together to give an opinion or stance on a particular issue. This often involves bringing together a range of currently available evidence. The downside is that the opinion will include some of the group’s own biases.

A recent example of a professional group summarising evidence is the Scottish Consultants in Dental Public Health Group, Recommendations on the use of fluoride toothpaste and fluoride supplements in Scotland 2017[3]. The document is clearly referenced and has been produced in consultation with a renowned guideline development group. This type of opinion holds more weight and can be taken more seriously.

Case reports/Case series

A large number of articles published in dental journals tend to be case reports or case series. They are based on one or very few cases. Treatment is often provided by one practitioner with a particular special interest or expertise. It may be difficult to directly replicate the treatment situation. Also, the patient characteristics are unlikely to be exactly the same as your patient.

They are particular useful in the case of rare or serious events. A case series published in 2012 presented two cases of fatal anaphylaxis following irrigation of tooth extraction sockets with chlorhexidine[4]. Rare events such as this can change practice very rapidly.

Case-control studies

Case control studies are retrospective observational studies. They do not test an intervention but are used to help find out what might cause a disease or be associated with it. As the name suggests, they are made up of two different groups, cases and controls. Cases will have the particular disease of interest and will be compared to controls that do not have the disease of interest. Researchers will take extensive histories from both groups and compare factors such as lifestyle. They are useful for establishing risk factors that are associated with a disease.

Recently there has been a lot of interest in understanding the causes of dementia. With an ageing population, if we could find out how to prevent dementia then this could have a great impact on the health of the population. One hypothesis queries whether periodontitis has any association with dementia. A research group in Granada carried out a case control study to find out if there was such an association. They compared 180 people with cognitive impairment to 229 without any impairment. After controlling for known risk factors they found there was a statistically significant association between periodontitis and dementia[5].

As mentioned before, case control studies are useful for establishing if associations exist between risk factors and disease. A lot more evidence is required in order to prove causation and establish the sequence. In this example, one might question whether the periodontal disease came before the dementia or whether the patient developed dementia and then stopped brushing as well as before? If you want to learn more about causation, then a good starting point is to read about the work of Sir Austin Bradford Hill. Sir Bradford Hill was an epidemiologist during the 19th century, in an after dinner speech he set out a number of considerations that should be taken into account when trying to establish causation[6].

Cohort studies

Cohort studies are another form of observational study and are much more useful in establishing causes of disease. As the name suggests, they include a cohort of people with all the subjects included in the study initially free from the disease of interest. Detailed histories and in some cases examinations take place at the beginning of the study. The cohort is then followed up, often over a number of years, and observed for signs of the disease.

One of the most famous cohort studies took place in the US in a town called Framingham. The town in Massachusetts was to be the centre of a study that has now lasted 69 years. It focused on understanding the causes of cardiovascular disease as public health specialists recognised this as a major threat to the population of the US. People in the town who were free of cardiovascular disease were enrolled in the study and observed for many years. Detailed information on behaviour, lifestyle and other characteristics were recorded. Investigations including blood pressure monitoring and ECG’s were carried out as the study progressed. It took 10 years for the first key finding to emerge. The researchers were able to show that as blood pressure increased, the incidence of coronary heart disease also increased[7]. The study produced the foundations of preventative medicine and discovered many of the causes for heart disease that we aim to prevent today.

Randomised controlled trials

A randomised controlled trial is the study of choice for testing new interventions in dentistry. They are experimental in nature and use randomisation techniques to reduce risk of bias and confounding factors that may influence outcomes. Patients are selected against strict inclusion and exclusion criteria ensuring they have similar baseline characteristics. There are then randomised into two arms, treatment and control. In the treatment arm, the subjects receive the new treatment under investigation. This is compared to the subjects in the control arm who will receive either placebo or current standard therapy.

Using a randomisation process to allocate patients to the different arms of a trial reduces the risk of selection bias, which is present when there are systematic differences between baseline characteristics of the groups being compared. Randomisation is best done using a computer-generated sequence that is independent of influence from the investigators. A trial that conceals group allocation from both the patient and the investigator is described as double-blind, in that neither know if they are receiving the new treatment or the alternative be that a placebo or standard care. At the end of the trial, the outcomes from each arm are then compared for any differences and inferences drawn on whether the treatment is effective.

There have been many randomised controlled trials (RCT) in dentistry, all of varying standards. Although an RCT is high in the hierarchy of evidence, it is still important to critique how the research was carried out and to what standard. We will cover that in article two.

Systematic reviews

The highest level of evidence is a systematic review. They bring together all the existing evidence on a particular question. Systematic searches of the literature are initially broad and can result in thousands of hits on databases such as PubMed. The review team will set criteria to focus the review down to include studies that answer specific questions. They then carry out critical appraisal of the studies to assess quality. If the studies all measure similar outcomes then the results of the trials can be compared by extracting the data and using statistical techniques in a meta-analysis. This gives more weight to the studies.

Guideline development groups

Guidance documents aim to bring together the current best available evidence on a given topic and make recommendations. National Guidance Groups such as Scottish Dental Clinical Effectiveness Programme, Scottish Intercollegiate Network and the National Institute for Clinical Excellence comprise a team of expert researchers and clinicians. They have a formal methodical approach to appraising the evidence; they combine this with expert opinion to arrive at their recommendations. We will look more at guidance and the influence they have on practice in the next article, which will feature an interview with Dr Doug Stirling from SDCEP.

Conclusion

So now we have reached the top of the pyramid and it should be becoming clear that there is a wealth and variety of information out there. We should be mindful of what evidence exists for the treatment we are providing our patients. Each type of study or research has its own pros and cons. The next article will focus on the practicalities of where to find the evidence, how to get the most out of databases and, importantly, how to critique the evidence you find.

 


Get involved

General dental practitioners have opportunities to get involved in clinical trials, especially in Scotland. A number of trials have been run from the University of Dundee including the IQuad trial which is an acronym for Improving the Quality of Dentistry. This trial looked at the effectiveness of the simple scale and polish on periodontal disease with published results expected soon. Find out more here.

The FiCTION trial, again it is an acronym, which stands for Fillings in Children Teeth Indicated or Not. Find out more here.

Recruitment to the latest clinical trial called REFLECT is ongoing. The trial is focused on understanding more about the effectiveness of 5000ppmf toothpaste. Dr Carly Ross BDS (Gla) MJDF (RCSEng), clinical research fellow and honorary specialty registrar in special care dentistry at the University of Dundee Dental School, explains about the role of general dental practitioners in helping shape the evidence.

Why does evidence-based dentistry matter to a general dental practitioner?

General dental practitioners have an important role to play in evidence-based dentistry. Along with the current scientific evidence and the patient’s needs, a GDP’s own clinical expertise helps to shape the concept of evidence-based dentistry. From this, clinical guidelines can be produced which assist GDPs in providing high-quality clinical care using the best available evidence.

How can dentists get involved in trials and shaping of the evidence?

Ninety percent of dental care is provided in primary care so it is essential that research is conducted in this setting. Many clinical trials take place in primary care in Scotland so input from GDPs is important to allow high-quality research to be carried out. The REFLECT clinical trial is being carried out in general dental practices and aims to evaluate the effectiveness and cost benefit of prescribing high dose fluoride toothpaste in older adults. The trial is currently recruiting practices in Scotland to take part.

If you are interested in taking part, please email reflect@dundee.ac.uk or call 01382 381 213 for more information.

 


Editor’s view

The Cochrane Collaboration carry out systematic reviews that include evidence derived mainly from randomised controlled trials. They use strict methodology and techniques for carrying out reviews and they can be thought of as setting the standard of how reviews should be conducted.

Dr Thomas Lamont, clinical research fellow and honorary specialty registrar in restorative dentistry at Dundee Dental School, is a clinical editor with Cochrane. Below he tells us in some more detail about the methods used in a Cochrane review and what his role is.

Who is involved in a Cochrane systematic review?
What is the skill mix?

Cochrane systematic reviews will include multi-disciplinary teams including patient representatives, clinicians, clinical academics, methodologists, statisticians, health economists, editors and
copy editors.

You are a clinical editor, what is your role?

As clinical editor, I help the review groups by providing clinical and methodological advice to the teams. I also help to peer review Cochrane reviews to ensure they meet the required Cochrane standards. I also provide lectures/seminars on the Cochrane review methodology to clinicians and academics.

Why does reviewing the evidence matter?

It is important that we review and integrate the evidence to ensure that we provide the best possible care for our patients. This cannot be done in isolation and needs to be combined with our own clinical experience and the wishes/values of our patients.

What relevance do the results of a Cochrane review have to a general dental practitioner?

Cochrane reviews provide high-quality evidence for use in the field. They add to the evidence base and distil a large amount of information, therefore making it easier for clinicians to make sense of all the
available evidence.

Find out more about Cochrane here: oralhealth.cochrane.org


References

1. American Dental Association. [Online] American Dental Association, 2017.

2. SUNY Downstate Medical Center. Medical Research Library of Brooklyn. Evidence Based Medicine Course. A Guide to Research Methods: The Evidence Pyramid.

3. Scottish Consultants in Dental Public Health Group, read online 24 March 2017. Recommendations on the use of fluoride toothpaste and fluoride supplements in Scotland 2017.

4. Chlorhexidine and hypersensitivity reactions in dentistry. M.N. Pemberton, J. Gibson. s.l.: British Dental Journal, 2012, Vol. 213.

5. Is periodontitis a risk factor for cognitive impairment and dementia? A case-control study. Gil-Montoya JA, Sanchez-Lara, Carnero-Pardo C, Fornieles F, Montes J, Vilchez R et al. Granada: J Periodontaol, 2015, Vol. 86.

6. The Missed Lessons of Sir Austin Bradford Hill. Phillips CV, Goodman KJ. Texas: BioMed Central, 2004.

7. The Framingham Heart Study and the epidemiology of cardiovascular disease: a historical perspective. Syed S mahmood, Daniel Levy, Ramachandran S Vasan, Thoma J Wang. 9921, s.l.: The Lancet, 2014, Vol. 383.

 

Bibliography

• Derek Richards, Jan Clarkson, Debora Matthews, Rick Niederman. Evidence based Dentistry: Managing Information for Better Practice. London: Quintessence Publishing; 2008.

• Jan Clarkson, Jayne E harrison, Amid I Ismail, Ian Needleman, Helen Worthington. Evidence-Based Dentistry For Effective Practice. London: Martin Dunitz; 2003.

About the authors

Derek Richards BDS, FDS, MSc, DDPH,FDS(DPH), is a consultant in dental public health, editor of the Evidence-based Dentistry Journal and director of the Centre for Evidence-based Dentistry now based at the Dental Health Service Research Unit in Dundee. He holds honorary senior lectureships at Dundee and Glasgow Dental Schools and is a specialist advisor to the Scottish Dental Clinical Effectiveness Programme (SDCEP). He has been involved with a wide range of evidence-based initiatives both nationally and internationally since 1994. He is co-author of the book, Evidence-Based Dentistry: Managing Information for Better Practice (Quintessential of Dental Practice) and the chief blogger for the Dental Elf website.

Niall McGoldrick BDS, MFDS RCPS(Glasg), is a specialty registrar in dental public health and is currently studying for his masters of dental public health at the University of Dundee. He graduated from Dundee Dental School in 2013 and then went onto complete longitudinal dental foundation training and dental core training in a range of specialities in Scotland including a placement with the SDCEP. He is a co-founder of the Scottish Charity, Let’s Talk About Mouth Cancer that is focused on the early detection of mouth cancer. He has received multiple awards for his work both inside and out of the NHS. Most recently, he received a National Award, NHS Young Achiever, from NHS Scotland and Scottish Government.

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]
.

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
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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:
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4. www.cancerresearchuk.org [Internet]. 2017 Available from:
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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.

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