Electrospray ionization and collision-induced dissociation of antibiotic polyether ionophores

The hypothesis of the present study was that previous experience of caries may serve as an indicator for individualised bitewing examinations in 15-19-old adolescents. One hundred adolescents, all 19 years old, were randomly selected from the files of public dental clinics in the County of Orebro. For 93 adolescents the total number of radiographs were summed for every patient from the age of 3 to 19 by assessing the files of public dental clinics and by assessing the files of the dental radiology department. All sets of bitewing radiographs from 14 up to and including the age of 19 were assessed with respect to approximal caries. The average number of intraoral radiographs exposed in a patient from the age of 3 through 19 was 24.4. It was shown that 70 to 80% of 14-19-year-old-adolescents had had a bitewing examination every year. The decision to perform a bite-wing examination in a 15-year-old was significantly correlated to the number of surfaces with initial caries at the age of 14. In the other age groups, none of the investigated variables was found to be significantly correlated to the performance of radiographic examinations.     

Peer approaches for increasing HIV awareness on a college campus

PURPOSE: To compare the accuracy of clinical examination performed with bitewing radiographs or clinical examination using tooth separation to identify carious lesion activity. MATERIALS AND METHODS: 320 surfaces from 40 bitewing radiographs were examined for approximal caries on the maxillary and mandibular primary molars of 20 patients 3-10 years old. The patients were divided into three groups: (1) Absence of the permanent first molar; (2) Partial eruption of the permanent first molar; and (3) Full eruption of the permanent first molar. Two examiners evaluated the radiographs using a megascope, a magnifying glass (x2), and an amplifying image screen. Approximal radiolucencies were identified on 72 surfaces. Following the radiographic examinations, the two examiners performed conventional clinical inspection using a No. 4 dental mirror, a No. 5 dental explorer, and an air-water syringe, with artificial light and relative isolation. The separation method was performed with elastic bands, which were removed after 24 hours, and the clinical examination conducted as in the non-separation group. RESULTS: The correlation between the extension of interproximal radiolucent lesions in primary dentition and their clinical diagnoses following separation of the teeth, was similar to findings on literature evaluating the permanent dentition. On radiographic findings for enamel lesions, white spots predominated both in the inner (100%) and in the outer (94%) half of enamel upon clinical examination with separation of teeth. For radiolucent lesions in dentin, on the other hand, cavities predominated over white spot lesions (84%). In Groups 1 and 2 (young primary), white spots occurred in cases where the radiolucent lesions reached the dentin (15% and 25%), similar to findings for young permanent teeth. Clinical diagnosis performed with the mechanical separation of teeth cannot be considered conclusive for the primary dentition.     

The use of bitewing radiographs in the management of dental caries: scientific and practical considerations

The objective of this paper is to synthesize published research on the use of radiographs in caries diagnosis in order to produce recommendations for guidelines that are clinically oriented but scientifically based. The options available include the use of various types of radiographic examination alone or in conjunction with other diagnostic aids. The outcomes should facilitate the optimal management of lesions as either preventive care advised (PCA) or operative care advised (OCA). Small initial lesions (PCA) require prompt detection, the application of appropriate preventive care and subsequent monitoring to maintain the most favourable tooth state achievable in the long term. Larger dentinal lesions (OCA) also require prompt detection so that appropriate high-quality operative care can be provided before further loss of tooth substance. Evidence was collected from the literature by updating several recent reviews by the author. The values employed were broadly analogous to those of the Canadian Task Force on the Periodic Health Examination. The use of ionizing radiation is always associated with a degree of risk: therefore all exposures must be kept as low as is reasonably achievable. Present evidence on the balance of risk and benefit indicates that the diagnostic yield for caries diagnosis is high enough to justify individualized examinations, particularly as changes in the morphology of caries have rendered clinical diagnosis of dentinal lesions less sensitive. This issue must be kept under review as alternative diagnostic technologies develop. There is good evidence that initial posterior bitewing radiographs are required for all new dentate patients over five years of age with posterior teeth. This procedure is required as an adjunct to clinical examination for the detection of caries on both the approximal and occlusal surfaces of the teeth. Although a 'blanket' regimen of routine radiographic examination at fixed intervals cannot be advocated, individualized bitewing examinations at varying frequencies determined on the basis of caries risk are supported. At the initial visit, an assessment of caries risk of the individual patient should be made. Varying intervals of first radiographic recall can then be suggested on the basis of differing degrees of risk. At present, risk assessment is imprecise, and risk status may change over time. Therefore, intervals between subsequent radiographic examinations must be re-assessed for each period. The purpose of detecting individual lesions should be to facilitate the planning of appropriate preventive treatment decisions based on lesion severity, caries risk and the patient. Different treatment should be employed for lesions in the PCA and OCA categories. Further rigorous studies are required to evaluate diagnostic methods appropriate for use in individual patient care, epidemiology and clinical research, and to increase the understanding of how findings from these applications inter-relate. Development and validation of reliable methods of caries risk assessment which are usable in general practice is a priority. Investigations of the processes involved in, and the outcomes of, dental decision-making are required to ensure that existing and new methods are used appropriately. Further work should develop and evaluate effective mechanisms of disseminating and implementing research findings by information transfer to dental educators and clinicians.     

A survey of general dentists in Ontario, Part II: Knowledge and use of topical fluoride and dental prophylaxis practices

A mail questionnaire was used to assess variations in the knowledge and practices of Ontario dentists with respect to topical fluoride and prophylaxis procedures. The questionnaire was answered by 1,276 general dentists. A high percentage (72 to 83 per cent) of respondents identified six months as the optimal time interval at which both procedures should be repeated for all patients under 19 years of age. Relatively few dentists (< 10 per cent) indicated that there should be no specific time interval for re-treatment (i.e. that it should be individually selected). The respondents' preventive knowledge was found to be deficient in two areas: few dentists (16 per cent) knew that it is not necessary to provide a prophylaxis prior to topical fluoride application to achieve maximum caries protection; and most dentists overestimated the speed of caries progress from outer enamel to the dentinoenamel junction (DEJ) in both primary (83 per cent) and permanent (82 per cent) approximal tooth surfaces. In bivariate analysis, three variables were found to be consistently and significantly related to optimal time intervals selected for both topical fluoride application and prophylaxis procedures: year of graduation from dental school; level of hygienist employment; and percentage of patients with private insurance. Multivariate analysis also identified three significant variables: year of graduation from dental school; level of dental hygienist employment; and practice business. Continuing education courses are suggested as a means of updating dentists' knowledge regarding preventive services. Studies are needed to determine the extent to which recent recommendations regarding the professional application of topical fluorides have been followed.     

Comparative study of antifungal activity of sertaconazole, terbinafine, and bifonazole against clinical isolates of Candida spp., Cryptococcus neoformans and dermatophytes

The aim of this study was to investigate the visibility of secondary caries in the gingivobuccal and gingivolingual corners of teeth restored with amalgam restorations. Standard Class II cavities were created in 15 orthodontically extracted mandibular premolar teeth, and the teeth were randomly divided into five groups of three teeth each. In four of the groups, a 1.0- or 1.5-mm cavity was prepared in the gingivolingual or gingivobuccal corner of the restoration. No lesions were created in group 5, the control group. The teeth were restored with amalgam. The teeth were adapted in the actual tooth space of 15 volunteers with one mandibular premolar missing. Radiographs of each patient were taken with the bisecting-angle technique and the bite wing technique. The radiographs were sorted at random and given to 15 members of the professoriate who were often involved in detecting caries and to 17 members who were not normally involved in detecting caries. The bitewing technique was found to be more reliable than the bisecting-angle technique in detecting secondary caries in gingivobuccal approximal corners (P < .05). It was also found that, in group 1, the bisecting-angle technique was more reliable than the bitewing technique in detecting caries in gingivolingual corners (P < .05). No significant differences were found in the correct evaluation of radiographs between the faculty who were normally involved in the detection of caries and those who were not.     

The reasons for tooth extractions in adults and their validation

OBJECTIVES: To investigate the primary reasons for the extraction of permanent teeth in adults and to validate the dentists' reasons for extraction. METHODS: Twenty-one dentists in the Greater Manchester area took part in the study. These dentists provided extracted teeth stored in 10% buffered formal saline together with details of the patient's age, sex, dental attendance pattern and the reason for extraction. In order to validate the reasons for extraction, teeth were examined for the presence or absence of coronal and root caries. A subgroup of 80 teeth, half of which were extracted primarily for caries and half for periodontal reasons were selected, stained and attachment loss measured at six sites per tooth to validate periodontal reasons for extraction. RESULTS: Three hundred and eighty-nine teeth were collected of which 37% were extracted primarily due to caries and 29% due to periodontal disease. Caries was the main reason for extraction in patients under 50 years, whereas periodontal disease was the commonest reason in the over-50 age group. Irregular attenders had more extractions for caries than regular attenders but attendance pattern did not affect the proportion of teeth extracted for periodontal reasons. The mean greatest loss of attachment on teeth extracted for periodontal reasons was 12 mm compared with 6.5 mm for caries. CONCLUSION: In this group of patients caries was the most common reason for extraction of teeth but periodontal disease became a more important reason for extraction after 50 years of age. The study validated the dentists' given reason for extraction.     

Dental practitioners' experiences on the usefulness of restorative materials in Finland 1992-1996

OBJECTIVE: To analyse general dentists' choice of restorative materials in Finland, where the use of amalgam has significantly decreased and the use of composites increased during the past 10 years. DESIGN AND SETTING: Postal survey in 1997 to a random sample of general dental practitioners mainly working with adult patients. MAIN OUTCOME MEASURES: Percentage distribution of dentists' opinions. RESULTS: The response rate was 82%. Tooth-coloured restorations were considered to be more time consuming, technically complicated and to have shorter life spans. Most dentists were not willing to return to the wide-scale use of amalgam restorations. CONCLUSIONS: The rapid changes in the restorative material selection have not resulted in serious problems in restorative therapy.     

Insulin effects on ouabain binding in A6 renal cells

OBJECTIVES: This study sought to identify risk markers associated with the provision of new restorations in children and to investigate whether the carious status of a tooth surface is associated with the restorative decisions of dentists. METHODS: A total of 911 schoolchildren in grades one, two, and three were randomly selected from the island of Montreal, Quebec, Canada. Dental examinations were carried out in 1990, 1991, and 1992. Tooth surfaces of first permanent molars were classified as sound, noncavitated, and cavitated. The carious status of a tooth was matched with restorative decisions reported to the insurance board. RESULTS: The presence of a carious cavity was a strong risk marker for placement of new restorations (odds rations > or = 4.11). After one year, less than 2 percent of sound tooth surfaces of first permanent molars were restored and about 21 percent of noncavitated tooth surfaces were restored. When new class I restorations placed in maxillary first permanent molars within 3-6 months after the baseline examination were evaluated, we found that between 73 percent and 86 percent of these new restorations were placed in sound or noncavitated tooth surfaces. A similar trend also was observed in mandibular first permanent molars. Poor agreement between epidemiologic diagnosis and restorative decisions was found. The restorative profile of dentists was a significant risk marker for placement of new restorations. CONCLUSION: The majority of new restorations in first permanent molars were placed in sound and noncavitated tooth surfaces because of the ubiquitous prevalence of these tooth surfaces and the validity problems of current caries diagnosis methods.     

Developmental eye disease--a genome era paradigm

Usually, the French dental insurance system covers the cost of restorative treatment but does not reimburse the cost of preventive therapies. A French sick-fund covering self-employed persons tested a new dental benefit plan for children intended to provide an incentive to develop office-based preventive activities. The programme, which started in 1992, concerns all 4-year-old children of self-employed workers in a single French region (Auvergne). Participants undergo an annual examination by the dentist of their choice until their 15th birthday. If the child is seen every year, all services related to dental caries (preventive and restorative) are provided free of charge. An ongoing evaluation of the programme was necessary to determine its influence on the development of office-based preventive activities and the dental health of the participants. A cohort of children enrolled in the programme in 1992 was followed over 4 years to examine the patterns of service use. In addition, a cross-sectional study comparing the caries experience of all 8-year-old children participating continuously in the programme (test sample) with that of a sample of control children (n=90) was conducted in 1996. Data from the longitudinal follow-up indicate that 43.37% of the 551 children to whom the programme was offered in 1992 underwent an annual examination in the first year. Of the children enrolled in 1992, 55.2% were still participating in the programme in 1996. Results showed that independent practitioners continued to focus on restorative treatment rather than preventive therapy. Results from the cross-sectional study are in accordance with this trend. The number of caries-free children was identical in test and control samples and the mean dft, DMFT, DT and dt did not vary between the two groups (Student's t-test, P>0.05). However the mean number of filled teeth was significantly higher in the test children than in the controls (P<0.01). For children with caries, the mean dft was 23.5% greater in the test group than in the control group (P<0.05). In Auvergne, a large number of families were not ready to participate in a plan that required them to take their child to the dentist every year. There was not a perceived need for regular preventive dental care, an attitude probably reinforced by the interventionist approach undertaken by the dentists over the survey period. Moreover, the plan did not provide an incentive for dentists to develop office-based preventive activities.     

Substrate specificity of rat liver aldehyde dehydrogenase with chloroacetaldehydes

The aim of the present study was to validate dentists' periodontal reasons for extraction by comparison with the in vitro periodontal status of extracted teeth. A national systematic random sample of Norwegian dentists (n = 500) was requested to record primary, secondary and tertiary reasons for tooth extraction for a period of 2 weeks in 1988. The response rate was 70%. The extracted permanent teeth from the first 2 patients of each dentist were collected. Of the 365 teeth, 329 satisfied the criteria for assessment of periodontal attachment after staining. Using a dissecting microscope (10x), 4 to 8 linear measurements were recorded per tooth. 159 of the 329 teeth had loss of periodontal support. Of the 93 teeth for which the dentists' reason for extraction included periodontal considerations, 1% had 1-10% loss of attachment, 59% had 11-50% loss and 40% had 51-76% loss of periodontal support. There was a significant correlation between in vitro measurements of attachment loss and a ranking of teeth on a scale from 1 to 3 based on the dentists' emphasis on periodontal reasons for extraction (The Spearman Rs = 0.29, p < 0.01). The results suggest that the forceps level for removal of teeth for periodontal reasons was set at a relatively early stage of the disease process by Norwegian dentists, and that there was a weak association between attachment loss and the dentists' emphasis on periodontal reasons for extraction.     

A randomized, controlled trial of a behavioral intervention to prevent sexually transmitted disease among minority women

Using annual bite-wing radiographs, the incidence and progression of approximal caries (4d-7m) were assessed longitudinally in teenagers and adolescents whose treatment had been based on remineralizing rather than restorative strategies. A closed cohort of 536 children initially was followed from 11 to 22 years of age. The scoring system was: 0 = no visible radiolucency; 1-2 = radiolucency in the enamel up to the enamel-dentin border; 3 = radiolucency with a broken enamel-dentin border but with no obvious progression in the dentin; 4 = radiolucency with obvious spread in the outer half of the dentin, and 5 = radiolucency in the inner half of the dentin. Caries rates were estimated as the number of new lesions/100 tooth surface-years, and the Kaplan-Meier estimate was used to calculate the cumulative survival time of each approximal surface. Three events were used: the transitions from states 0 to 2, 2 to 4 and 3 to 4. The results showed a considerable variation between the surfaces in both caries rates and survival time. For all surfaces combined, the median caries rate from state 0 to 2 was 3.9 new lesions/100 tooth surface-years; from state 2 to 4, the rate was 5.4, and from state 3 to 4 it was 20.3. Of the sound surfaces (state 0), 75% survived 6.3 years without reaching state 2. Given state 2, 75% survived 4.8 years without reaching the outer half of the dentin (state 4), while given a lesion at the enamel-dentin border (state 3), 75% survived 1.3 years without doing the same. The median survival time of lesions from state 3 to 4 was 3.1 years. The group with DMFSappr>1 at the age of 11-12 years had a risk of new approximal enamel lesions (state 0-2) that was 2.5 times greater than that of the group with DMFSappr = 0-1.     

Diagnosis and treatment planning for implant dentistry

Dental implants are well-established in dentistry and allow the restorative dentist to offer patients the best that dentistry has to offer. Through examination, radiographs, and study models, the restorative dentist and implant surgeon can develop a treatment plan. Comprehensive diagnosis and treatment planning involve much more than a clinical exam--they require an investigation involving past, present and future dental therapy.     

Dental hygiene self-regulation: an educational perspective

Dental hygiene's pursuit of self-regulation has been impeded from its beginning by conceptual discrepancies. It is often confused with independent practice and/or other scope of practice issues, all of which cloud the real impetus: true professional status. The authors suggest this confusion could be addressed by the educational system. Students in schools offering education to future professionals must have an opportunity to gain insight into the political environment of their respective fields in addition to acquiring the theory and skills designed to make them clinically proficient. Through increased awareness of issues related to governance, they will be able to make informed decisions about matters affecting their chosen profession. From the outset, the objective of this investigation was to unveil some of the common misconceptions about self-regulation held by students of dental hygiene and dentistry. Following a review of the literature, 11 of the most recurrent points of confusion were incorporated into a true/false survey. The survey addressed the following issues as they relate to dental hygiene self-regulation: ability to practice independent of dentists' supervision, ability to diagnose dental caries, scope of practice expansion, dissolution of the "dental team", compromised client safety and increased income-generating potential. The survey was distributed to dental hygiene and dentistry students across Canada. The results indicate a general lack of understanding of the concept of self-regulation among the Canadian dental hygiene and dentistry student population.     

Access to dental care--experiences of men with HIV infection in the United Kingdom

A piloted self-complete questionnaire enquiring about dental experiences was administered to a consecutive sample of men with asymptomatic HIV infection attending a dedicated clinic in London. Forty-seven men completed questionnaires. Despite a high level of dental attendance before diagnosis of HIV infection, 60% of the men had not visited a general dental practitioner since diagnosis. Nineteen men had visited a dentist since diagnosis; 15 had been refused or deterred by members of the dental team and 5 had attended without disclosing their HIV status. These data indicate that despite professional guidance to dentists, the perceptions of dentists held by people with HIV and the behaviours of dentists acts as barriers to care. Dedicated dental clinics act as an important safety-net for people with HIV infection.     

Research with families in palliative care: conceptual and methodological challenges

The aims of the present study were to investigate the ability of 3 experienced clinicians to detect occlusal carious lesions, assess their depth, diagnose their activity and define a logical management for each lesion. The material consisted of 35 third molars scheduled for extraction or surgical removal making it possible to validate the accuracy of the clinical recordings histologically. Examinations were carried out at baseline and after 4 months in order to monitor lesion progression. At the first visit a radiograph was taken; the number of filled surfaces was counted and the oral hygiene assessed generally and by disclosing occlusal plaque of the tooth under examination. After cleaning the occlusal surface caries was recorded in a selected investigation site using a visual ranked caries scoring system, as well as an electrical conductance recording (ECM). Apart from counting fillings and taking new radiographs the same procedure was performed at the second visit, which then was followed by extraction of the tooth. After sectioning the tooth lesion depth was recorded, and lesion activity, based on acid production, was assessed using methyl red dye. Lesion activity was also judged by means of polarized light microscopic examinations of the sections. Results showed strong relationships between the visual, ECM and radiographic assessments and both lesion depth and lesion activity. In contrast, all other parameters were poorly related to lesion activity. Changes in visual assessments and in conductance readings from first to second examination were poorly associated with lesion activity. In conclusion, clinicians are able to detect lesions, predict activity and severity and define a logical management of occlusal caries on the basis of a single examination.     

Networking with Internet

In forensic odontology, registration of dental characteristics is crucial in the identification procedure. It has been found that the most common errors made are incorrect registration of restorations and confusion about premolars and molars in both jaws. In an earlier study, dental students were observers and the charting was made without radiographs. However, in practical forensic work dentists make the registrations and radiographs are usually available. In this investigation eight dental students and eight dentists made registrations on ten excised macerated jaws with the aid of radiographs. The mean number of errors for each jaw for the students and the dentist was 4 and 3 respectively. The most common error among the dentists was incorrect registration of restorations, while errors on registrations of missing teeth were most common among the students. Even though the material in this study was limited, the results indicate the importance of re-examining of postmortem findings before the comparison with the antemortem data is done. Additionally, the forensic work should be performed by specialists.     

Epinephrine in digital blocks: revisited

STATEMENT OF PROBLEM: Implant treatment in the United Kingdom has been provided mainly in specialist, regional dental hospitals. However, increasingly, general dentists are providing implant-supported prostheses in a private office setting. PURPOSE: This study investigated the nature, timing, and frequency of complications associated with single tooth implant therapy in a dental hospital and two dental offices. METHODS: The dental records of 58 patients provided with 76 implants during the period of 1989-95 were reviewed retrospectively. Fifty-three single tooth crowns on implants were placed by general dentists and 23 by specialists in the dental hospital. RESULTS: Implant survival rate was 96%. Twenty-eight guided bone regeneration procedures were required, including 13 unplanned ones. Prosthodontic complications included the need for recontouring of three crowns and the recementation of three crowns. Only two abutment screws required retightening. Peri-implant soft tissue inflammation occurred around six crowns and recession around two. CONCLUSION: The single tooth implant-supported crown appears to be an effective and durable restorative treatment with a relatively low prevalence of postoperative complications.     

Radiographic and histological methodologies in estimating the chronology of crown development in modern humans and great apes: a review, with some applications for studies on juvenile hominids

There has been a burgeoning of interest in the last decade on growth studies in hominids. These studies have relied heavily on dental development, and have compared juvenile hominids to modern human and ape standards, which are usually established using radiographic data. There has been considerable discussion on the most appropriate methods of deriving population standards from radiographs, but very little on the accuracy of the radiographic image itself. Previous histological and dissection studies have shown that age at onset of mineralization is overestimated, and age at crown completion is underestimated using radiographs. This study considers the process of X-ray absorbence by mineralized tissues and the formation of radiographic images of developing teeth. Following tooth initiation a critical mass of mineral is required for the tooth to register superimposed on the absorbence of alveolar crypt bone, which accounts for the late identification of tooth initiation. Determination of completion of crown growth depends upon the identification of the last formed enamel at the cervix. Recognition of this key stage is difficult as crown growth slows towards the cervix, and the last secreted enamel may take months to attain full mineralization levels due to the prolonged maturation process. Morphological and geometric factors have a significant influence on the imaging of the completed crown. The last formed enamel is located on the buccal face, where enamel thins progressively to nothing. X-ray absorption by enamel at the cervix becomes insignificant, and may be counterbalanced by increased dentine absorption. Approximal enamel in contrast is clearly visualized once maturation is complete. However, developmentally this enamel face initiates later, and is completed much earlier than buccal enamel. All of the radiographic estimates of crown completion times are based upon interpretations of approximal enamel completion. These considerations suggest that the human population standards in current usage may not represent true anatomical and chronological stages of crown development, and care should be taken in referring juvenile hominids to these radiological standards.     

Practice characteristics of dental hygienists operating independently of dentist supervision

PURPOSE: This paper presents business characteristics of ten experimental independent dental hygiene practices operating in California between 1987 and 1990. Sixteen dental hygienists participated in the experiment, the Health Manpower Pilot Project 139 (HMPP 139). HMPP 139 dental hygienists wanted to work independently in traditional office-based settings, institutional settings, and other arrangements. They worked in group and solo practices, on a full- or part-time basis. METHODS: Data were collected from the HMPP 139 practices on services provided, patient visits, fees charged, referrals to dentists, acceptance of Medicaid patients, and services to organizational clients. Data collection methods varied, depending on the question addressed. Surveys of dentists' offices provided data on fees and Medicaid policies for comparison with the independent dental hygiene practices. RESULTS: All experimental practices attracted new patients for each quarter in operation. These practices mostly provided prophylaxis treatments; however, a wide variety of services was provided. Fees charged in HMPP 139 office-based practices were less than comparable fees charged in dentists' offices. At least one-third of patients in the HMPP 139 office-based settings received a referral to or an opinion about a dentist from the dental hygienist. HMPP 139 practices were more available to Medicaid patients than were California dentists offices. Each experimental independent practice provided care to at least one client in a nontraditional setting. CONCLUSIONS: The HMPP 139 practices consistently attracted new patients. This suggests independent practice for dental hygienists may be a viable and flexible alternative if the practices can stabilize total patients at a sufficiently high level. An independent practice alternative might increase access to care, contain fees, and direct the flow of patients to dentists. Further study is needed to test these findings.     

Factors related to mortality of aged patients hospitalized with community-acquired pneumonia

OBJECTIVE: To investigate the proportion of a sample of approximal carious lesions extending up to 1 mm into dentine which progressed over a 3-year period and to examine factors which influenced that progression. DESIGN: Prospective, single centre, clinical study. SETTING: Restorative Clinic at Bristol Dental School, UK. SUBJECTS AND METHODS: Sixty-five adult patients were identified who each had an approximal carious lesion which extended up to 1 mm into the dentine and which were assessed at intervals of up to 36 months. All patients were given appropriate preventive advice. MAIN OUTCOME MEASURES: Progression of the lesions was determined by assessment of sequential bitewing radiographs. RESULTS: 29% of the lesions progressed within 8 months, 56% by 20 months and 69% by 36 months. After 36 months, lesions which extended over 0.5 mm and up to 1 mm into the dentine were significantly more likely to have progressed (92%) compared with shallower lesions which extended up to only 0.5 mm into dentine (50%). CONCLUSIONS: The depth of an approximal dentine lesion was the main clinical marker which related to its progression. It is recommended that operative intervention is considered for approximal lesions which extend deeper than 0.5 mm into the dentine, while preventive treatment and re-assessment may be considered for shallower lesions.