Impact of stress on dentists' clinical performance. A systematic review.

INTRODUCTION: Dentistry is recognised as a stressful profession and dentists perceive their profession to be more stressful than other healthcare professions. While earlier studies have shown a link between stress and well-being among dentists, whether stress negatively impacts their clinical performance is an important and open question. We do know, however, that stress is associated with reduced performance in other health (and non-health) related professions. OBJECTIVES: This systematic review aimed to answer the question: how does stress impact on dentists' clinical performance? METHODS: This systematic review was registered in PROSPERO (CRD42016045756). The CINHAL, Embase, Medline, PsycINFO, EThOS and OpenGrey electronic databases were searched according to PRISMA guidelines. Two reviewers independently screened the citations for relevance. The citation list of potentially eligible papers was also searched. Prospective empirical studies were considered for inclusion. The inclusion criteria were applied at the full-text stage by the two same reviewers independently. RESULTS: The search yielded 3535 titles and abstracts. Twelve publications were considered potentially eligible, eleven of which were excluded as they did not meet the predefined inclusion criteria. CONCLUSIONS: This systematic review identified a gap in the literature as it found no empirical evidence quantifying the impact of stress on dentists' clinical performance. Prospective well-designed experimental simulation studies, comparing stress with non-stress situations on clinical performance and decision making, as well studies evaluating prospectively real-life dentists' performance under stress are warranted.

Student perceptions of a spiral curriculum.

AIM: The aim of this study was evaluation of constructive alignment of student perceptions to a spiral curriculum, as a pre-requisite to successful learning. METHOD: A survey was undertaken to evaluate student thoughts and experiences of a spiral curriculum, by participation in an anonymous voluntary questionnaire. Students were asked to rate their thoughts on their understanding, perceived benefit of and confusion with their spiral curriculum at the current time and retrospectively during previous years, and to answer free-text questions on the impact, effects on learning and future suggestions for their spiral curriculum. RESULTS: Sixty (86%) students completed the questionnaire. Understanding the spiral curriculum worked enhanced with time, with the benefit of the spiral curriculum being felt more conclusively in the latter years, and the majority of students not being confused by the spiral curriculum. Those students who were most confused by the spiral curriculum were the ones who were least likely to appreciate its benefits. The opportunity for consolidation of previously visited knowledge was a perceived predominant advantage, with re-visitation of topics helping to deepen understanding and learning. Clarity on the depth of knowledge at each stage prevents information overload. A spiral curriculum must spiral and not be a repetition of previously delivered topics. CONCLUSIONS: This study provided insights into students' perceptions of an integrated spiral curriculum, and whilst predominantly positive, there are challenges to enhance the student experience. The spiral curriculum provides an opportunity to revisit and consolidate learning to the apparent benefit of the student.

Identifying dentists' attitudes towards prevention guidance using Q-sort methodology.

OBJECTIVE: To gain insight into the attitudes and motivating factors of dentists working in the English National Health Service (NHS) towards prevention guidance. DESIGN: Q-methodology: an established hybrid quantitative/qualitative technique used in the social sciences to categorise subjects based on their views by considering factors as part of their overall decision-making profile. SETTING: General Dental Practices offering care under an NHS contract. SUBJECTS AND METHODS: NHS dentists (n = 26) placed 36 statements about prevention guidance derived from an earlier study into a distribution grid that ranked the statements from "most agree" to "most disagree". Principal components factor analysis was applied to determine the principal patterns in the rankings of statements. RESULTS: Analysis indicated a total of six distinct profiles within the responses, of which three profiles had at least six dentists loading onto them. The first profile was strongly characterised by dentists who appear motivated to provide prevention but financial and time constraints prevent them from doing so. The second was characterised by dentists using prevention guidance but restricting its use to only certain patients. The third was characterised by dentists who appeared "health-focused". They placed importance on working to prevention guidance, but were keen to have greater patient and professional support in achieving this. CONCLUSION: In this group of dentists Q-methodology identified three main profiles to the delivery of prevention guidance.

Barriers and facilitators that influence the delivery of prevention guidance in health service dental practice: a questionnaire study of practising dentists in Southwest England.

UNLABELLED: Objective: OBJECTIVE: To investigate the barriers and facilitators influencing the delivery of prevention in accordance with a national guideline (Delivering Better Oral Health, Department of Health England) in health service dental practice. DESIGN: Self-completion questionnaire. SETTING: Health service general dental practices. SUBJECTS AND METHODS: Questionnaires were sent via two mailings to all 508 dentists registered to work in health service general dental practice in Devon, South West England. RESULTS: In total 266 questionnaires were returned (52% response rate). Examples of barriers and facilitators were evident at various organisational levels of dentistry. These were principally the healthcare system, practice (dental office) arrangements and professional factors. Respondents gave positive responses to questions concerning the flexibility (53%) and benefit of the guideline (63%) and they tended to indicate that they didn't perceive problems in changing their old routines (58%). Opinion was divided among respondents on whether they felt patients followed their advice (49%). There was overall agreement that delivering prevention in practice is problematic if there are insufficient staff (68%), facilities (53%) and time (60%). Encouragingly most respondents felt adequately trained to deliver the evidence based prevention guidance (59%). CONCLUSIONS: This study has identified some barriers and facilitators to the delivery of prevention guidance in this group of health service dentists with no single factor viewed consistently as more important than any others. A further qualitative study is planned to investigate in more depth the reasons underpinning the responses given in this study.

The prevalence of opportunistic pathogens associated with intraoral implants.

AIMS: The aim of this study was to determine the prevalence and proportions of opportunistic pathogens harboured on orthodontic retainers. METHODS AND RESULTS: First, Staphylococcus spp. and Candida spp. were isolated from the retainer's inner surface and from other mucosal surfaces of the subject's mouth by routine bacterial culture. The prevalence and proportions of these micro-organisms on retainers was compared in different areas of the mouth within a group of retainer wearers, and mucosal carriage was compared to a group of nonretainer wearers. Staphylococcus spp. were isolated from 50% of the retainers and comprised on average 8·4% of the viable microbiota. Candida spp. comprised 0·13% of the viable microbiota and were recovered from 66·7% of the retainers. Neither genus was isolated from nonretainer wearers. Second, the two most commonly worn retainers manufactured from different materials were sampled; again Staphylococcus spp. and Candida spp. were recovered; however, no statistical differences were observed between the devices. CONCLUSIONS: Opportunistic, nonoral, pathogenic micro-organisms were recovered from orthodontic retainers. SIGNIFICANCE AND IMPACT OF THE STUDY: It is possible that an orthodontic retainer could be a reservoir for opportunistic pathogens and act as a source of cross-, self- and re-infection.

Potential oral manifestations of cardiovascular drugs.

OBJECTIVE: The aim of this work was to determine the frequency and nature of oral manifestations secondary to use of cardiovascular drugs. METHODS: Five hundred and thirty one patients attending an adult cardiology clinic in Saudi Arabia were questioned about the occurrence of oral dryness, dysgeusia, or burning sensation and were clinically evaluated for the presence of oral mucosal or gingival disease. Data were statistically analyzed with chi-squared tests, odds ratios and Student's t-test. RESULTS: Oral symptoms and/or signs were recorded in 75 (14.1%) patients with xerostomia being the most common (7.5%), followed by lichenoid (lichen planus-like) lesions (3.6%) and dysgeusia (1.9%). Xerostomia was significantly more frequent in patients with a history of diabetes mellitus and in female patients (P < 0.05). There were no statistically significant differences (P > 0.05) between patients with or without oral manifestations when age, gender, cardiovascular risk factor, cardiac disease, type of cardiac drug used or the number of medications were assessed. There was a trend for xerostomia to be less frequent in patients receiving therapy with angiotensin converting enzyme inhibitors and a slight trend of xerostomia to be more likely with increased number of non-cardiac and total number of agents per subject. The number of non-cardiac and total medications taken by patients with potential oral manifestations tended to be greater than that of patients without oral manifestations. CONCLUSIONS: The frequency of potential oral manifestations in patients receiving cardiovascular agents was 14.1%. The occurrence and character of the oral manifestations had no significant relation with individual cardiac drugs, although there was a trend for oral manifestations to be likely with increasing number of drugs.

Randomised controlled trial of the efficacy of HybenX in the symptomatic treatment of recurrent aphthous stomatitis.

BACKGROUND: The treatment of recurrent aphthous stomatitis (RAS) is principally directed towards reducing the pain and duration of each episode of ulceration; however, there remain few agents for which there is definitive evidence of benefit. AIMS: The aims of the present study were to determine the efficacy of HybenX (Epien Medical Inc., Minneapolis, MN, USA), vs another device used for the treatment of RAS (Salicept; Carrington Laboratories Inc., lrving, TX, USA) to reduce the symptoms and duration of RAS and determine the safety of HybenX for this clinical application. MATERIAL AND METHODS: Sixty-three individuals (36 male, 27 female, group median age 25 years, range 17.8-57.9 years) were entered into a prospective randomised controlled trial of HybenX vs an occlusive covering device (Salicept oral patches; Carrington Laboratories). RESULTS: Painful symptoms over a 5-day posttreatment period were reduced by both agents although HybenX was statistically more effective at day 2 than Salicept, and there was a trend for HybenX to cause greater pain reduction than Salicept over this 5-day period. Both agents gave rise to few adverse side effects--a total of nine adverse events in eight patients were recorded. All were unlikely to be related to the treatment devices. HybenX was only applied on one occasion to the HybenX group, while individuals in the Salicept group were able to self medicate as required. The mean number of Salicept patches used per day per subject was three (s.d. 3.3) on day 1 posttreatment, 3.4 (s.d. 3.1) on day 2 and 2.7 (s.d. 1.9) on day 3. Thereafter, the number of applications fell to a mean of 0.8 on day 7. CONCLUSION: It is concluded that HybenX safely and effectively reduces the painful symptoms of RAS.

Onset and progression of clinical manifestations of orofacial granulomatosis.

BACKGROUND: There remain few studies describing in detail the early occurrence and long-term progression of clinical manifestations of orofacial granulomatosis (OFG) in a substantial number of patients. OBJECTIVES: The aim of this study was to determine the early and late clinical manifestations of a large case series of patients with OFG. PATIENTS/METHODS: Clinically relevant data of 49 patients with OFG who attended an Oral Medicine unit in the UK were examined retrospectively. The analyzed parameters included occurrence and typology of initial manifestations at onset and with respect to long-term follow-up. RESULTS: Five major patterns of disease onset were observed. Recurrent facial swelling with/without intra-oral manifestations was the single most common presentation at onset followed by intra-oral ulcers, and other intra-oral and neurological manifestations. The majority of patients later developed a spectrum of additional features. CONCLUSIONS: OFG results in multiple manifestations at different time points. The disease onset is characterized by manifestations other than facial swelling in about half of affected individuals. However, patients can develop cosmetically unacceptable lip/facial swelling at a later stage. Nearly all affected individuals ultimately develop lip/facial swelling while about half of all patients develop oral ulceration.

Investigation of the effect of a proprietary dental waterline disinfectant on shear bond strengths of Panavia 21 to enamel and dentine.

This study investigated the effect of 'Alpron mint', a dental unit waterline disinfectant, on shear bond strengths between 'Panavia 21' resin based cement and tooth tissue. Eighty-eight human premolar tooth specimens were prepared in either enamel (N=44) or dentine (N=44). Half the specimens within each group were irrigated with an Alpron mint solution and the other half with distilled water (control) prior to application of Panavia 21 resin luting cement. There was no significant difference in shear bond strengths for both enamel and dentine with Alpron mint irrigation compared with distilled water (P = 0.245).

Cortical vascular canals in human mandible and other bones.

The human mandible is highly mineralized. We hypothesized that this is related to the local vascularity of the bone. This could not be examined directly, but, as a surrogate, intracortical vascular canal spaces of the human mandible were studied so that we could determine possible relationships with age, gender, location, dental status, and tissue mineralization. Canal numbers, area, and volume fraction were calculated from quantitative backscattered electron images of human mandibles aged 16-96 years. Data were compared with calvaria, maxilla, lumbar vertebra, femoral neck, and iliac crest. In the mandible, the buccal aspect of the midline was the most porous, the canals being larger and more numerous. The cortical porosity in the posterior of partially dentate mandibles was significantly greater than that of either dentate or edentate mandibles, and there was a significant increase in the size of canals in the mandible with increasing age. Female mandibles had more porous cortices. No relationship was found between cortical porosity and the degree of bone mineralization.

The cost-effectiveness of screening for oral cancer in primary care.

OBJECTIVES: To use a decision-analytic model to determine the incremental costs and outcomes of alternative oral cancer screening programmes conducted in a primary care environment. DESIGN: The cost-effectiveness of oral cancer screening programmes in a number of primary care environments was simulated using a decision analysis model. Primary data on actual resource use and costs were collected by case note review in two hospitals. Additional data needed to inform the model were obtained from published costs, from systematic reviews and by expert opinion using the Trial Roulette approach. The value of future research was determined using expected value of perfect information (EVPI) for the decision to screen and for each of the model inputs. SETTING: Hypothetical screening programmes conducted in a number of primary care settings. Eight strategies were compared: (A) no screen; (B) invitational screen--general medical practice; (C) invitational screen--general dental practice; (D) opportunistic screen--general medical practice; (E) opportunistic screen--general dental practice; (F) opportunistic high-risk screen--general medical practice; (G) opportunistic high-risk screen--general dental practice; and (H) invitational screen--specialist. PARTICIPANTS: A hypothetical population over the age of 40 years was studied. MAIN OUTCOME MEASURES: The main measures were mean lifetime costs and quality-adjusted life-years (QALYs) of each alternative screening scenario and incremental cost-effectiveness ratios (ICERs) to determine the additional costs and benefits of each strategy over another. RESULTS: No screening (strategy A) was always the cheapest option. Strategies B, C, E and H were never cost-effective and were ruled out by dominance or extended dominance. Of the remaining strategies, the ICER for the whole population (age 49-79 years) ranged from pound 15,790 to pound 25,961 per QALY. Modelling a 20% reduction in disease progression always gave the lowest ICERs. Cost-effectiveness acceptability curves showed that there is considerable uncertainty in the optimal decision identified by the ICER, depending on both the maximum amount that the NHS may be prepared to pay and the impact that treatment has on the annual malignancy transformation rate. Overall, however, high-risk opportunistic screening by a general dental or medical practitioner (strategies F and G) may be cost-effective. EVPIs were high for all parameters with population values ranging from pound 8 million to pound 462 million. However, the values were significantly higher in males than females but also varied depending on malignant transformation rate, effects of treatment and willingness to pay. Partial EVPIs showed the highest values for malignant transformation rate, disease progression, self-referral and costs of cancer treatment. CONCLUSIONS: Opportunistic high-risk screening, particularly in general dental practice, may be cost-effective. This screening may more effectively be targeted to younger age groups, particularly 40-60 year olds. However, there is considerable uncertainty in the parameters used in the model, particularly malignant transformation rate, disease progression, patterns of self-referral and costs. Further study is needed on malignant transformation rates of oral potentially malignant lesions and to determine the outcome of treatment of oral potentially malignant lesions. Evidence has been published to suggest that intervention has no greater benefit than 'watch and wait'. Hence a properly planned randomised controlled trial may be justified. Research is also needed into the rates of progression of oral cancer and on referral pathways from primary to secondary care and their effects on delay and stage of presentation.

What's in a bin: A case study of dental clinical waste composition and potential greenhouse gas emission savings.

BACKGROUND: Dental practices have a unique position as dental staff use a high number of dental materials and instruments on a daily basis. It is unclear how dentists' and dental care professionals' choices and behaviours around selecting and using materials impact on the amount of unnecessary waste production. Although there are a number of articles exploring the quality and quantity of waste in dental practices, there are no studies on organisational strategies to decrease unnecessary waste. There is no clear economic analysis of the impact on associated cost to dental practices which consequently can affect the access of dental care for disadvantaged groups. METHODS: This study used an audit approach to explore the potential for sustainability in dental practice by measuring the nature and quantity of dental clinical waste, and assessing the feasibility of measuring the financial costs and potential carbon savings in the management of dental clinical waste. CONCLUSIONS: The data from our study would appear to support the view that it is possible to reduce carbon emissions and increase profitability. Successful implementation of an environmentally sustainable approach to waste management will be dependent on the practicalities involved and the financial incentives for adopting such practices.

Social anxiety in orthognathic patients.

There is evidence that patients seeking orthognathic treatment may be motivated by social anxiety disorder (SAD). The aim of this study was to investigate SAD in orthognathic patients using the Brief Fear of Negative Evaluation Scale (BFNES) and to compare these findings with those of the general population. This was a cross-sectional, questionnaire study conducted in two parts. Firstly, a national survey was conducted to yield data for the BFNES from a large, random sample of the UK general population. Secondly, orthognathic patients completed the BFNES. The BFNES scores are reported in two formats: the original 12-item scale (O-BFNES) and a shorter eight-item version (S-BFNES). With regards to the national survey, 1196 individuals participated. The mean O-BFNES score was 29.72 (standard deviation (SD) 9.39) and S-BFNES score was 15.59 (SD 7.67). With regards to the orthognathic sample, 61 patients participated. The mean O-BFNES score was 39.56 (SD 10.35) and the mean S-BFNES score was 24.21 (SD 8.41). Orthognathic patients had significantly higher scores than the general UK population (P<0.001), and multiple linear regression revealed that age, gender, and patient status were all independent predictors of BFNES scores. From the results of this study, orthognathic patients experience significantly higher levels of social anxiety than the general population.

Introduction to cumulative meta-analysis in dentistry: lessons learned from undertaking a cumulative meta-analysis in periodontology.

Improving health and well-being from the consideration of isolated studies is problematic. Systematic reviews have been developed to address this problem and may include a quantitative data synthesis in the form of a meta-analysis, or a cumulative meta-analysis. The value of systematic reviews depends greatly on the availability and quality of the results of primary research. The objective of the current project was to demonstrate the technique of cumulative meta-analysis in dentistry using data from a previously published systematic review. The process highlights an issue that some trials could not be synthesized due to the lack of reporting of measures of variation. This represents a potential source of bias. Investigators are encouraged to consider their trials as part of an information continuum and to report sufficient detail to permit the trials' incorporation into subsequent syntheses.

British Dental Journal based Continuing Professional Development: a survey of participating dentists and their views.

OBJECTIVE: There is little information available on journal based verifiable continuing professional development (CPD). The aim of this study was to survey those dentists who have undertaken this form of CPD and elicit their views. DESIGN: A questionnaire survey. METHOD: Four hundred dentists who had registered to undertake CPD with the British Dental Journal (BDJ) were randomly selected and sent a questionnaire. RESULTS: Three hundred and twelve questionnaires were returned (78%) of these 181 (58%) were male and 131 (42%) were female. Of the 312, 307 had undertaken the BDJ CPD initiative. Two hundred and sixty eight respondents (87.3%) agreed/strongly agreed that the BDJ CPD satisfied their personal CPD needs. Two hundred and eighty three (92.2%) agreed/strongly agreed that their knowledge has been increased as a result of undertaking the BDJ CPD initiative. Two hundred and twenty agreed/strongly agreed (71.7%) that an element of their clinical practice had changed as a result of undertaking the BDJ CPD initiative. CONCLUSION: Journal based learning appears to be an effective way of undertaking verifiable CPD.

Person-centred care in dentistry--the patients' perspective.

OBJECTIVES: To develop an understanding of the key features of person-centred care (PCC) in relation to general dental practice from a patient's perspective. BACKGROUND: PCC is acknowledged as an important dimension of quality with 'patient experience' increasingly used as a marker of quality within the NHS. A Dental Quality and Outcomes Framework (DQOF) is currently being piloted in the UK, which includes patient experience as one of the three domains. It is recognised that there is limited understanding of PCC within dentistry, with little evidence published on the subject. METHODS: This study uses qualitative methods to explore the views of 16 purposively sampled patients living in Southwest England. In-depth semi-structured interviews were recorded, transcribed, coded and analysed thematically. RESULTS: PCC was viewed as key in the delivery of high-quality care. Dimensions of PCC were identified and categorised as relational or functional aspects of care. Relational aspects of care were viewed as being central to the delivery of PCC with five components identified and named: connection, attitude, communication, empowerment and feeling valued. Functional aspects of care were identified as healthcare system and physical environment and were noted to influence PCC to a variable degree. CONCLUSION: A model of PCC in dentistry is proposed which has been generated from empirical evidence that represents the views of patients. It is hoped that this may inform and influence development of a tool to measure PCC within any future version of the DQOF.

Is alcohol responsible for more intra-oral cancer?

The role of the major risk factors, tobacco smoking and alcohol consumption, on trends in intra-oral cancer mortality in England and Wales between 1911 and 1990 was investigated, using lung cancer and liver cirrhosis as surrogate markers for smoking and drinking. Standardised mortality data on lung cancer and liver cirrhosis from the Office of Population Censuses and Surveys, aggregated into 5-year time periods for ages 35-64 and 65+ years, were regressed on corresponding data for intra-oral cancer. The strongest associations were in males aged 35-64 with a high negative correlation between lung and intra-oral cancer (rho=-0.98, 95% CI -0.99 to -0.96, P<0. 01) and, conversely, a positive correlation between liver cirrhosis and intra-oral cancer (rho=0.71, 95% CI 0.34 to 0.89, P<0.01). The findings suggest that rising alcohol consumption since the 1950s is more closely related to increasing intra-oral cancer incidence and mortality than smoking, most notably among younger males since the early 1970s.

An audit of the efficacy of the oral brush biopsy technique in a specialist Oral Medicine unit.

The diagnosis of oral epithelial dysplasia has traditionally been based upon histopathological evaluation of a full thickness biopsy specimen from lesional tissue. It has recently been proposed that cytological examination of "brush biopsy" samples is a non-invasive method of determining the presence of cellular atypia, and hence the likelihood of oral epithelial dysplasia. The present audit determined, retrospectively the sensitivity, specificity and positive and negative predictive values of the oral brush biopsy technique in the diagnosis of potentially malignant disease in a group of 112 patients attending a specialist Oral Medicine unit. The sensitivity of detection of oral epithelial dysplasia or squamous cell carcinoma of the oral brush biopsy system was 71.4% while the specificity was 32%. The positive predictive value of an abnormal brush biopsy result (positive or atypical) was 44.1%, while the negative predictive value was 60%. It is concluded that not all potentially malignant disease is detected with this non-invasive investigative procedure.

Optimum bitewing examination recall intervals assessed by computer simulation.

OBJECTIVE: To assess the effect of altering bitewing examination recall intervals on health gain from dental restorative treatment and to determine optimum recall intervals under varying clinical conditions. DESIGN: A computer simulation of the caries process in posterior approximal tooth surfaces. The effect of superimposing restorative treatment, based on diagnoses from bitewing radiological examinations carried out at differing time intervals, was incorporated. Input data included caries attack rates, median survival times of restorations, and sensitivity (Sn) and specificity (Sp) of treatment decision making by a high (A) and a low (B) performing dentist. PARTICIPANTS: A hypothetical population, initially 14-15 years old. INTERVENTIONS: Class II amalgam restorations. OUTCOME: Health gain in utility based units (UBUs) was assessed relative to interim end point UBUs pertaining under 'do nothing scenarios'. RESULTS: One thousand approximal surfaces, designated initially as 920 sound, 51 carious and 29 filled were followed in the model over 10 years. The greatest health gain (39.33 UBUs) was from dentist A (Sn = 0.23, Sp = 0.99, restoration median survival time = 20 years, caries rate = 4.4% per annum, optimal recall interval between bitewing radiological examinations = 7 months). The least was from dentist B (Sn = 0.52, Sp = 0.88, median survival time = 5 years. caries rate = 0.0% per annum, optimal recall interval between bitewing radiological examinations > 120 months) representing a loss of 16.79 UBUs compared with 'do nothing'. CONCLUSIONS: In the best interests of their patients, it would seem that dentists need to exercise considerable caution in making positive decisions to restore approximal tooth surfaces on the basis of bitewing radiographic evidence and that for some dentists current guidelines for bitewing examination intervals would appear to be too permissive.

Health gain from restorative dental treatment evaluated by computer simulation.

OBJECTIVE: To simulate the influence over time of relevant factors on health gain from restorative dental treatment under varying assumptions and to compare outcomes with those resulting under a 'do nothing' scenario. DESIGN: A decision model was used in a computer simulation of the caries process in posterior approximal tooth surfaces. The effect of superimposing restorative treatment, based on bitewing radiology, was incorporated. Input data came from current observational studies and included caries progression rates, notional survival times of restorations, and sensitivity (Sn) and specificity (Sp) of treatment decision making by a high (A) and a low (B) performing dentist. Utility values, on a scale 0-1, for different tooth health states were obtained from questioning 92 adults of appropriate age. SETTING: By assumption, the primary dental care sector. PARTICIPANTS: A hypothetical population, initially 14-15 years old. INTERVENTIONS: Class II amalgam restorations. OUTCOME: Computed in utility based units (UBUs) as sums of the product of numbers of sound, carious and restored surfaces and their utility values. Health gain (in UBUs) was assessed relative to interim end point UBUs pertaining under 'do nothing'. RESULTS: One thousand approximal surfaces, designated initially as 920 sound, 51 carious and 29 filled were followed in the model over 10 years. The greatest health gain (33.16 UBUs) was from dentist A (Sn = 0.23, Sp = 0.99, 50 per cent restoration survival rate = 10 years, caries rate = 4.4% per annum). The least was from dentist B (Sn = 0.52, Sp = 0.88, 50% survival = 5 years, caries rate = 0.0% per annum) representing a loss of 17.07 UBUs compared with 'do nothing'. CONCLUSIONS: Results suggest that caution is advisable when making positive decisions to restore on the basis of bitewing radiographs.