Diagnosis of Carious Lesions

The key question was, "What are the validities of the available diagnostic methods for detecting carious lesions in primary and permanent teeth?" The team evaluated the evidence for six diagnostic methods, radiographic, visual/tactile, visual, EC, FOTI, and laser fluorescence. We found a total of 39 studies describing 126 assessments of these methods. The vast majority of these assessments involved posterior occlusal and proximal surfaces of permanent teeth. Too few assessments addressed diagnosis on primary teeth and anterior teeth to permit any conclusions to be drawn. No assessments addressed diagnosis on root surfaces. The evidence was unevenly distributed among methods, with assessments of radiographic methods accounting for over one-half of all assessments. The assessments were also unevenly distributed with respect to the type of lesion to be identified, with just under one-half diagnosing lesions penetrating into dentin and only 11 examining diagnosis of enamel lesions. The small number of assessments for most applications and the extent of the variation among assessments when several are available precluded any definitive conclusions about expected sensitivity and specificity levels. Thus, the strength of the evidence describing the validities of diagnostic methods for carious lesions was rated as poor for all applications of all diagnostic methods.

Some general observations about relative sensitivity and specificity values are possible for some diagnostic methods. For all but one diagnostic method, the specificity of a given method for the diagnosis of any type of lesion on either proximal or occlusal surfaces typically will be greater than its sensitivity. Thus, the diagnostic criteria employed in conjunction with these methods favor making more false negative diagnoses in the presence of disease rather than false positive diagnoses in the absence of disease in almost all instances. The exception to this observation was EC diagnoses of caries penetrating into dentin, where some studies indicated higher sensitivity than specificity.

For radiographic methods on occlusal surfaces for the diagnosis of any lesions, lesions into dentin, and lesions confined to enamel, reported sensitivities tended to fall into two ranges, a low range between 0.15 and 0.35 and a higher range between 0.50 and 0.70, whereas specificity was generally above 0.75. To a lesser extent, this same pattern occurred for visual and visual/tactile methods on these surfaces, with slightly more variation in specificity values than for radiographic methods. On proximal surfaces, this pattern was evident only when the presence of any type of lesion is the diagnostic challenge and then only for radiographic diagnoses.

The assessments reviewed did not offer evidence for the superiority of either visual/tactile or visual methods. However, the number of assessments available for this comparison was small. Similarly, assessments of radiographic methods did not contain clear evidence for the superiority of digital techniques, although here the weight of the available evidence suggested that use of some digital methods offers small gains in sensitivity without reduction in specificity and that image analysis techniques may offer more substantial gains. There were too few assessments of FOTI and laser fluorescence methods to permit even general observations. Finally, the results of assessments of EC were suggestive of heightened sensitivity compared with other methods, but at the cost of reduced sensitivity, which would result in more false positive diagnoses. Further, the evidence base for EC displayed the greatest number of threats to internal and external validity.

In addition to the limitations in scope noted above, we found the diagnostic literature problematic with respect to several design and reporting issues. A majority of studies reviewed provided incomplete information describing methods and criteria for histologic validation, criteria for selection of samples, and examiner reliability. The absence of this information limited the ability to generalize results or compare them across studies. The preponderance of in vitro studies, the high prevalence of lesions in most in vitro samples, the limited variety of posterior teeth on which performance was assessed, and the small number of examiners in one-half of the assessments all raised concerns about external validity. Differences in histologic criteria for carious lesions raised concerns about internal validity, as did the practice in some studies of identifying the optimal diagnostic criteria post hoc. Internal validity may also be threatened in the studies that relied on one examiner, especially when several assessments were performed by the individual on the same sample of teeth.

Management of Noncavitated Carious Lesions

The key question was, "What are the efficacies of the nonsurgical methods available for stopping or reversing the progression of a noncavitated coronal carious lesion in a primary or a permanent tooth?" The team evaluated the evidence for fluoride rinses, fluoride topicals, fluoride varnishes, silver nitrate, and occlusal sealants. With the exception of the fluoride topical applications, each method was represented by a single study. The evidence for each of the methods is rated as incomplete.

The team found this literature to be seriously limited in scope, with only five studies included in the review. Within this small number of studies, the team identified limitations caused by the variety of methods used for identification of noncavitated lesions at baseline and by study design issues including identification and control of other preventive dental exposures and high losses to followup at least partially a result of including only full participants in the analyses.

Management of Caries-Active Individuals

The key question was, "What are the efficacies of the methods available for reducing the incidence of new coronal carious lesions in primary and permanent teeth in individuals who are deemed to be "caries active" or at "high caries risk?" The team evaluated the evidence for nine methods: fluoride varnishes, fluoride topical solutions, fluoride rinses, CHX varnishes, CHX topical solutions, CHX rinses, combined CHX-fluoride applications, sealants, and other approaches. The evidence for the efficacy of fluoride varnishes is rated as fair and the evidence for all other methods as incomplete. Although the team felt that the evidence was suggestive of efficacy for CHX varnishes, CHX gels, and combination treatments including CHX agents, the available studies were too few and too small to support any other conclusion. Similarly, the evidence for the efficacy of sucrose-free gum was found to be suggestive, but again the small number of studies necessitated an incomplete rating.

The team also examined studies of subjects from two special populations known to be at elevated risk of dental caries to examine the evidence for efficacy in these groups. In subjects undergoing orthodontic treatment with attached bands or brackets, the evidence for efficacy of fluoride interventions was found to be suggestive, but incomplete. In individuals receiving head and neck radiotherapy, the literature offered fair evidence for the efficacy of fluoride-based interventions. In both populations, the evidence for any other intervention was also incomplete.

Because the evidence for efficacy is incomplete for nearly all of the interventions described, the team was not able to evaluate the relative efficacy of these interventions. Only three reports of harms associated with any of the interventions were found, each involving CHX. In two instances, some mild staining was noted and in the third, four adult experimental subjects discontinued participation amidst complaints about taste and burning sensations.

The number of available studies for any specific method was found to be a serious limitation. Among studies addressing a method, the variety of experimental protocols, comparison groups, and other community and individual preventive dentistry exposures further restricted the opportunity to draw conclusions about the efficacy of the method. Finally, generalization from the studies to the broader U.S. population is problematic as nearly all studies included only children and evaluated changes only in the permanent dentition.