The clinical behaviour of free smooth surface carious lesions monitored over 2 years in a group of Scottish children

Modern Concepts of Caries Measurement

Following the consideration of several recent systematic and other reviews, there is a growing professional and scientific consensus that caries measurement methodology in caries clinical trials (CCT) should be updated to reflect progress made elsewhere in cariology. In this paper, therefore, “modern” means accepted in contemporary dental research and dental practice on the basis of sound research evidence—not necessarily new or requiring the use of new technology. Caries measurement should be seen in the context of the objectives of modern clinical caries management and the continuum of disease states, ranging from sub-surface carious changes through to more advanced lesions. Measurement concepts can be applied to at least three levels: the tooth surface, the individual, or the group/population. All are relevant to CCTs. Modern clinical caries management can be seen as comprised of seven discrete but linked steps (Steps 2, 3, and 4 are directly concerned with measurement.): (1) ‘Caries detection’ represents a yes/no decision as to whether caries is present; (2) lesion measurement assesses defined stages of the caries process, taking into account the histopatholgical morphology and appearance of different sizes and types of lesion and the diagnostic threshold(s) being used; (3) lesion monitoring by repeated measures at a series of examinations is used when lesions are less advanced than the stage judged to require operative intervention (A comparison of serial measurements permits the efficacy of preventive care aiming either to arrest or to reverse the lesion to be assessed.); (4) caries activity measures would be very valuable, but are relatively poorly developed and tested at present; (5) diagnosis, prognosis, and clinical decision-making are the important human processes in which all the information obtained from steps 1 to 4 is synthesised; (6) interventions/treatments, both preventive and operative, are now routinely used for caries management; and (7) outcome of caries control/management assesses caries management by examining evidence on the long-term outcomes. A challenge for the future is to define a range of optimal caries measurement methods—in use or in development in recent trials, in clinical practice, and/or in caries epidemiology—that will best contribute to more efficient, modern caries clinical trials.

Reliability of the Nyvad criteria for caries assessment in primary teeth

This study assessed the interexaminer and intra-examiner reliability of the Nyvad caries classification system in primary teeth and calculated the mean examination time. The criteria were based on visual and tactile examinations to differentiate active and inactive lesions at cavitated and non-cavitated levels. Eighty children (3-7 yr of age) were examined under standardized conditions by calibrated examiners. At the tooth surface level, reliability was expressed as percentage agreement and kappa coefficient, using four diagnostic thresholds: sound vs. diseased; sound or inactive lesion vs. active lesion; intact surface vs. surface discontinuity; and sound or non-cavitated lesion vs. cavitated lesion. Interexaminer and intra-examiner kappa values were, respectively: 0.82/0.86; 0.80/0.86; 0.90/0.94; and 0.95/0.98. At the individual level, reliability of estimates of the caries prevalence and of the decayed or filled surface (dfs) counts were assessed at three diagnostic thresholds: sound vs. diseased; sound or inactive lesion vs. active lesion; and sound or non-cavitated lesion vs. cavitated lesion. For caries prevalence, interexaminer and intra-examiner kappa values were, respectively: 0.84/0.94; 0.69/0.74; and 0.95/0.97. The mean examination time was 226.5s (SD = 128.5). The use of the Nyvad caries diagnostic criteria in primary teeth showed reliable results. The examination time was acceptable.

Epidemiological assessment of predictors of caries increment in 7-10- year-olds: a 2-year cohort study

Objective

The aim of this 2-year cohort study (2003 to 2005) was to investigate how caries experience, at initial lesions (early or non-cavited lesions) and cavited stages, predicts caries increment in permanent teeth in 7-10- year-olds.

Material and Methods

The random sample of 765 children attending public schools in the city of Piracicaba, SP, Brazil, was divided into two groups: 423 children aged 7-8 years and 342 children aged 9-10 years. All subjects were examined by a calibrated examiner, using dental mirror and ball-ended probes, after tooth brushing and air-drying in an outdoor setting, based on the World Health Organization criteria. Active caries with intact surfaces were also recorded as initial lesion (IL). Univariate analysis was used for statistical analysis (Odds Ratios and Chisquare).

Results

The association between the DMFT (decayed, missing and filled teeth) increment and the presence of IL was significant only for 9-10-year-old children. The children with DMFT>0 at baseline were more prone to have DMFT increment, with the highest risk for caries increment occurring in children aged 7-8 years.

Conclusion

The predictors of caries increment were the presence (at baseline) of caries experience in permanent teeth for both age groups (7-8; 9-10-year-olds) and the presence of the IL (at baseline) for 9-10-year-olds.

Relationships between occlusal or free-smooth and approximal caries in mixed dentition

This cross-sectional study aimed to examine the relationships between free-smooth or occlusal surfaces and approximal caries in 104 schoolchildren between 6 and 8 years of age. Caries diagnosis was clinically and radiographically assessed, and white spot lesions, evident caries lesions or restorations, as well as radiolucence in enamel were considered to be caries. In the studied subjects, the correlations were analyzed in the 1st primary molars (Ds), the 2nd primary molars (Es), the 1st permanent molars (6s), and all molars. The data were statistically analyzed by chi-square test. Significant correlations between occlusal surface caries and approximal surface lesions were observed in Ds and Es teeth and in all molars, but not for 1st permanent molars. For free-smooth surface, these correlations were significant only for Es and all molars. Sensitivity and specificity for occlusal surface as an indicator of approximal caries in the same tooth type ranged from 73% to 83% and 51% to 58%, respectively. Similarly, for free-smooth surface the values varied from 22% to 60% and 57% to 90%, respectively. Sensitivity and specificity for occlusal surface caries in identifying subjects with approximal caries were 78% and 70%, respectively; for free-smooth surface, the corresponding values were 59% and 65%, respectively. The results suggest that visually detected caries lesions are indicative of approximal caries. Thus, if a certain risk limit is defined and the corresponding number of caries lesions in different surfaces is reached, the risk is above the threshold and could be a practical guideline on the need for radiography in this age group of patients with "moderate caries experience".

Visual and visuo-tactile detection of dental caries

The objective of this review is to describe and discuss the content validity of a sample of caries detection criteria reported in the literature between January 1, 1966, and May 1, 2000. Using filters to locate randomized or controlled clinical trials on dental caries, fluorides, sealants, and "restorative" care, I identified a total of 171 documents from MEDLINE and the Cochrane Collaboration's Oral Health Group (CC-OHG) special register. These articles met the following inclusion criteria: (1) Data had been collected from samples of patients or populations; and (2) dental caries was assessed clinically, and criteria were either published or described in the paper. From the selected articles, evidence tables were prepared describing each caries detection criterion. Analysis of the content validity of the criteria systems was based on evaluation of the disease process, exclusion of non-caries lesions, subjectivity, use of explorers, and drying of teeth prior to examination. This review included 29 unique criteria systems. Of those, 13 originated from the UK, 3 from the USA, 4 from Denmark, and others from the World Health Organization (WHO), Sweden, Switzerland, Norway, Netherlands, and Canada. Thirteen of the criteria systems either measured active and inactive early and cavitated lesions or defined separate criteria for smooth and occlusal tooth surfaces. Nine systems measured early as well as cavitated stages of the caries process, and 7 measured cavitation only. Eleven of the criteria systems provided explicit descriptions of the disease process measured or information on how to exclude non-caries from caries lesions. The use of explorers and drying and cleaning of teeth varied widely among the criteria. The majority of the newly developed criteria systems originated from Europe. In conclusion, this review of the content validity of the 29 criteria systems found substantial variability in disease processes measured, inclusion and exclusion criteria, and examination conditions.

Construct and predictive validity of clinical caries diagnostic criteria assessing lesion activity

Even though there is no "gold standard" for determining caries lesion activity, it is nonetheless possible to evaluate the validity of such diagnostic measures. The aim of this study was to estimate the construct and predictive validity of caries lesion activity assessments by means of their ability to reflect known effects of fluoride on caries. A three-year trial of the effect of daily supervised brushing with fluoride toothpaste was carried out among 273 12-year-old children. All children were examined clinically according to diagnostic criteria for activity assessment. The relative risk (fluoride vs. control) for caries lesion transitions among diagnostic categories was calculated. Fluoride inhibited progression of caries at all stages of lesion formation while at the same time enhancing lesion regression. The effects were most pronounced for active non-cavitated lesions. It is concluded that the clinical diagnostic criteria have construct and predictive validity for the assessment of caries lesion activity.

Impact of diagnostic criteria on the prevalence of dental caries in Norwegian children aged 5, 12 and 18 years

The study aimed to investigate caries prevalence in children using a severity grading diagnostic system, and to evaluate the influence of different diagnostic thresholds on the caries data. A group of 513 children, aged 5, 12 and 18 years, were examined clinically, and with available bitewing radiographs, by four calibrated examiners. The inter- and intra-examiner reliability, assessed by a weighted kappa, varied between 0.80 and 0.95. The mean dmft/DMFT values were 3.8, 5.8 and 11.0 for the three age groups respectively, and the corresponding dmfs/DMFS values were 5.4, 9.9 and 22.6. The d/D-component constituted the major part of the dmf/DMF index in all age groups, and enamel lesions accounted for 59%, 89% and 86% of the d/D-component in the three age groups respectively. It is concluded that enamel or initial caries lesions contributed substantially to the total caries prevalence, illustrating the importance of using diagnostic criteria that include all stages of clinical caries if a total picture of the caries situation is needed.

Diagnostic tools and measurements--impact on appropriate care

The diagnosis of primary coronal caries should be seen as a complex process, comprising both detection and measurement phases, which enables clinicians, researchers and epidemiologists to make informed decisions about the management and prognosis of the disease process. The different diagnostic thresholds employed for measurements of caries experience can be viewed as an iceberg, a metaphor which demonstrates the ambiguity of the term "caries free" and which can also represent the differing management options appropriate for the care of different types of active and inactive lesions: NAC (No Active Care). PCA (Preventive Care Advised) and OCA (Operative Care Advised). There are considerable methodological difficulties in drawing valid comparisons between studies using incompatible criteria and simulations. However, it is apparent that no caries diagnostic tool in current clinical use fulfils all of the ideal criteria for measurements needed to plan and monitor appropriate care. Systems providing reliable serial measurements with which to assess future caries risk and present caries activity are urgently required as diagnostic tasks are becoming both more difficult and more important from the standpoint of long-term oral health. Existing diagnostic tools frequently rely on subjective judgements and provide only semi-quantitative measures insensitive to smaller lesions. In the future tools are needed which are objective, quantitative and which can provide acceptable compromises between sensitivity and specificity for a wide range of applications for individual patient care as well as for research and survey use. Key problem areas with existing tools include confusion in terminology and between caries assessments made by clinicians and epidemiologists as well as the lack of valid measurements relating to the activity of primary root caries and secondary caries. Deficiencies with current tools impact on the care of individuals by allowing false negative diagnoses of hidden occlusal dentine lesions and approximal cavities on the one hand, whilst generating some false positive diagnoses on sound surfaces leading to inappropriate decisions to restore on the other. At the population level, current conventional tools significantly underestimate overall caries experience. In future the adoption of more accurate and reliable methods would facilitate more effective preventive care and promote more appropriate restorative treatment decisions. Research in this area should focus for the next five years on diagnostic technologies which: 1) inform valid prospective caries risk assessments for different age groups, 2) can help to determine present caries activity and monitor lesion behaviour over time and 3) help identify methods which can implement existing and new research knowledge about diagnostic tools into clinical and research practice.

How useful are cross-sectional data from surveys of dental caries?

Surveys are projects involving systematic data collection without a specific hypothesis to be tested and hence without a specific research design. This paper reviews their uses, and some of the issues involved with measuring dental caries in surveys. The principal benefits of surveys are in (a) monitoring trends in oral disease when the surveys are repeated periodically: and (b) giving dental health a visibility it might otherwise not get among policy-makers. On the other hand, they are of limited use in determining treatment needs for a population, evaluating treatment outcomes, and evaluating prevention programs. Some major issues in caries surveys today include difficulties with the DMF index; the use of exclusively visual versus visual-tactile criteria; "hidden" caries; and the appropriate role for early, non-cavitated carious lesions. The DMF index suffers from its mixing of disease and treatment, and more research is needed to determine the most appropriate role for exclusively visual criteria in surveys. Trade-offs, such as weighing the benefits of exclusively visual criteria against the probable greater difficulty in finding "hidden" caries, have not been determined. Inclusion of non-cavitated lesions in a survey will increase its cost. Organizers should therefore be clear before the survey on how this additional information will be used to justify the additional expense.

Clinical diagnosis of precavitated carious lesions

During the 20th century, dental caries was usually diagnosed using tactile-visual criteria that detected the presence of cavitation rather than measured the disease process as a continuum that starts from the appearance of microporosity, as a result of demineralization, to the occurrence of cavitation. With increasing understanding of the dental caries process and the role of primary and secondary prevention in arresting it, sensitive and specific diagnostic systems are needed that could enable dentists to detect signs of early demineralization and possible progression of precavitated carious lesions before the occurrence of cavitation. In this review of the literature, published validity studies of diagnosis of precavitated lesions were reviewed. Overall, the current clinical diagnostic systems have low sensitivity and moderate specificity. Good reliability of diagnosing precavitated carious lesions could be obtained for diagnosing pits and fissures but for smooth tooth surfaces the reliability is poor. As our diagnostic capability of precavitated lesions improves, there is a need for a significant change in dental education, dental insurance, and dental practice to reward dentists for promoting oral health and preserving tooth structure. In this paper, a new model for classifying carious lesions based upon the type of intervention strategies is proposed to assist in this new approach of caries management.

Assessment of single risk indicators in relation to caries increment in adolescents

Base-line data on a series of risk indicators were related to 11-month caries increment in 181 subjects with a mean age of 13 years and 3 months. A caries increment equalling or exceeding one tooth surface was recorded in 21% of the subjects. The risk indicators consisted of past caries experience, white spot lesions, visible plaque and gingivitis, and six salivary tests: secretion rate, buffer effect, sucrase, mutans streptococci, lactobacilli, and Candida. Significant associations between caries increment and past caries experience (p = 0.002), white spot lesions (p = 0.01), lactobacilli (p = 0.02), Candida (p = 0.006), and sucrase (p = 0.02) were observed. The ensuing odds ratios were thus recorded: past caries experience, 3.6; white spot lesions, 2.9; salivary sucrase activity, 2.9; lactobacilli, 2.5; and Candida, 2.8.

Incremental susceptibility of individual tooth surfaces to dental caries in Scottish adolescents

This study reports on the caries susceptibility of tooth surfaces in 4294 adolescents (mean age 12.5 yr) during a 3-yr, double-blind clinical caries trial, conducted in Lanarkshire, Scotland, between 1988 and 1992. Children were selected on the grounds of dental maturity and past caries experience. Clinical examinations with mirror, CPITN probe and fibre optic trans-illumination were carried out on the permanent dentition, with the buccal pits of mandibular molars and palatal pits of maxillary molars being recorded as separate sites. At baseline 6061 surfaces were decayed (1.0% of 601 160 surfaces examined), 20 160 (3.4%) filled, and 10 909 (1.8%) missing due to caries. The number of surfaces recorded as sound at baseline in subjects completing the study was 454 663. Of these 8176 (1.8%) new surfaces were decayed, 14 832 (3.3%) filled and 4000 (0.9%) missing at the final examination. Molar occlusal surfaces showed greatest susceptibility to attack, 35.8%) of those at risk becoming carious in the course of the study. All buccal and lingual smooth surfaces showed a low susceptibility, but 8.8% of buccal and palatal pits developed caries. At the final clinical-only examination, pit and fissure caries accounted for 48%, interproximal surfaces for 39%, and smooth surfaces for 13% of caries prevalence. However, overall the contribution of these surfaces to 3-yr increments was, 40%, 47% and 13%, respectively.

Relationships between free smooth surface and proximal caries in the young permanent dentition

Cross-sectional relationships between free smooth surface and proximal caries were assessed in 3 age groups, comprising 252 subjects aged 12 yr, 301 aged 15-16 yr and 102 aged 18-19 yr. Caries diagnosis was clinically on white spot and radiographically on enamel lesion level. Fair correlation between buccal-lingual and proximal caries observed among 12-yr-olds (r=0.47) declined in the older subjects (r=0.24). While statistically significant the variability in proximal caries, explained by buccal-lingual lesions, was low (range 6-22%). Sensitivity and specificity for buccal-lingual lesions as an indicator for proximal caries in the same tooth ranged from 0.37-0.44 and 0.84-0.91, respectively, with associated Pv+ and Pv- ranging from 0.41-0.44 and 0.84-0.91, respectively. Sensitivity and specificity for buccal-lingual caries in identifying subjects with proximal caries ranged from 0.33-0.44 and 0.67-0.98, respectively. Pv+ ranged from 0.94-0.99 and Pv- from 0.06-0.35. ROC curve analysis yielded A(z)-values of about 0.76 in the two younger age groups and 0.57 in the oldest. The results imply that information obtained from visual examination should be applied with caution when inferences about current caries status on proximal surfaces are made from the presence of buccal-lingual caries.

Preventive Care Advised (PCA)/Operative Care Advised (OCA)--categorising caries by the management option

Currently a range of systems and classifications are used by clinicians, epidemiologists and clinical research workers to sub-divide carious lesions into different grades. These systems are based on the depth of the lesion and/or the presence/absence of macroscopic cavitation. In order to improve upon the meaningfulness and comparability of such systems in the light of increasing knowledge about the disease process, lesion behaviour and caries management options, the authors propose a new system of categorisation that differentiates between lesions which normally require operative intervention and those which do not. In future, it is proposed that in addition to existing conventional criteria, diagnostic systems should also allow results to be expressed in terms of 1) lesions for which appropriate non-invasive Preventive Care Is Advised (PCA lesions) and 2) lesions for which Operative Care Is Advised (OCA lesions). Locally acceptable sub-divisions may have to be developed and agreed for certain specific applications. The adoption of this additional nomenclature and approach in the future should aid communications between the different groups involved in caries diagnosis and research. It may facilitate the dissemination of research findings, as well as helping to "drive" researchers working on caries diagnostic methods to focus on techniques which will aid in the accurate assessment of lesion activity and behaviour. Such a focus should also increase our understanding of treatment decision making and promote the development of clinical guidelines. The facility to retain existing criteria in parallel, for local and other purposes, would preserve comparability with data collected previously.

Some of the factors to be considered in the prescription and timing of bitewing radiography in the diagnosis and management of dental caries

This article describes some of the factors to be considered by the practitioner when prescribing bitewing radiographs in the diagnosis and management of dental caries and draws on the literature of a number of disciplines including restorative dentistry, cariology, epidemiology and oral radiology. It seems appropriate to re-assess current practice in the light of information on changes in the disease of dental caries, its behaviour and the way this behaviour may vary in high and low caries risk groups. The diagnostic potential of the bitewing examination appears, at present, to be unrivalled, but other diagnostic methods, such as fibreoptic transillumination and tooth separation, must also be considered. Some methods to minimize radiation doses and increase diagnostic yield are discussed. Current knowledge of prescribing patterns is reviewed and areas of ignorance are mentioned as findings from future research in these areas may influence decisions about when to use and re-use bitewing radiographs.