Dental caries is a widespread, chronic, infectious disease experienced by almost 80 percent of children by the age of 18 and by more than 90 percent of adults. Substantial variation exists in dentists� diagnosis of carious lesions as well as in the methods used by dentists to prevent or manage them. New methods of identifying carious lesions have appeared, and new approaches to the management of carious lesions�and for the management of individuals deemed to be at elevated risk for experiencing carious lesions�are emerging. A systematic review of the literature (Bader, Shugars, Bonito, 2000) was conducted to address three related questions concerning the diagnosis and management of dental caries: (a) the performance (that is, sensitivity and specificity) of available diagnostic methods; (b) the efficacy of approaches to the management of noncavitated, or initial, carious lesions; and (c) the efficacy of preventive methods for individuals who have experienced or are expected to experience elevated incidence of carious lesions.
Search Strategy
We conducted two searches of the relevant English-language literature from 1966 to October 1999, using MEDLINE, EMBASE, and the Cochrane controlled trials register. We also did a hand search of relevant journals published in November and December, 1999. (We did not investigate reports in the gray literature�that is, information not appearing in the periodic scientific literature.) One search focused on studies of six diagnostic methods (visual, visual/tactile, radiography, fiberoptic transillumination, electrical conductance, laser fluorescence) and combinations of these methods. A second search focused on studies of preventive or management methods for carious lesions, including fluoride applications, pit and fissure sealants, health education, dental prophylaxis, instruction in oral hygiene, removal of dental plaque, chlorhexidine application, and use of cariostatic agents.
Selection Criteria
The group of diagnostic studies included studies that involved histological validation of caries status and that either reported the results to show the sensitivity and specificity of the diagnostic method or that reported data from which those measures could be calculated. We excluded studies of diagnostic methods not commercially available.
The group of studies on dental caries management included only those on methods applied or prescribed in a professional setting and that were performed in vivo with a comparison group. In our selection of literature on the management of noncavitated carious lesions we only included studies where the lesion was the unit of analysis. In selecting literature on the management of subjects at elevated risk for dental caries, we only included studies where such determinations had been made on individual subjects, based on their carious lesion experience and/or bacteriological testing.
Data Collection and Analysis
We selected the studies for our report from among 1,407 diagnostic and 1,478 management reports by reading titles, abstracts, and, where necessary, full papers. We ultimately abstracted data (single abstraction, subsequent independent review) from two types of studies, using different forms of abstracting for the diagnostic and management studies. A quality rating form was completed by the research team for each of the three questions mentioned above, with different criteria employed for the two types of studies.
Diagnostic Review Results
We judged the strength of the evidence on the validity of the diagnostic methods evaluated to be poor. The evidence did not support the calculation of point estimates of sensitivity. There were almost no reports on the performance of any diagnostic method applied to primary teeth, anterior teeth, or root surfaces. The number of studies available on posterior occlusal and proximal surfaces of permanent teeth was sufficient for calculation of point estimates for some, but not all, of the methods. Even where the number of studies was sufficient, however, variations among them precluded such estimates. With the exception of electrical conductance, the diagnostic methods used criteria that maximized specificity at the expense of sensitivity: false positive diagnoses were proportionally infrequent, compared to false negative diagnoses. In addition to the limited numbers of studies on certain teeth and methods, the studies displayed a variety of serious limitations, including a predominance of in vitro studies, small numbers of examiners, high prevalence of lesions, and inadequate descriptions of subject selection methods, examiner training and reliability, and criteria for diagnosis.
Management Review Results
The literature examined on the management of noncavitated carious lesions consisted of five studies that described seven experimental interventions. Because these interventions varied extensively in terms of method used as well as other characteristics, no conclusions about the efficacy of these methods were possible. We therefore rated the evidence for the efficacy of management methods of noncavitated lesions as incomplete. Standardization in the determination of noncavitated status is needed.
The literature on the management of individuals at elevated risk of carious lesions consisted of 22 studies describing 29 experimental interventions. We rated the evidence on the efficacy of fluoride varnish for prevention of dental caries in high-risk subjects as fair, and the evidence for all other methods as incomplete. Because the evidence on the efficacy of some methods, including the application of chlorhexidine, use of sucrose-free gum containing xylitol, and combined chlorhexidine-fluoride methods is suggestive but not conclusive, these are fruitful areas for further research.
Conclusions
The evidence available to estimate the validity of diagnostic methods for carious lesions is insufficient. There are too few studies on many of the methods, and even when sufficient numbers of studies are available the substantial variations among them produce problematic results. The literature describing the management of two specific dental caries-related conditions�nonsurgical interventions for noncavitated lesions, and prevention of lesions in persons at elevated risk for new lesions�is inadequate to permit conclusions about the efficacy of most methods. For only two specific applications�fluoride varnishes in caries-active/high-risk individuals, and fluoride-based intervention for individuals receiving radiotherapy�was the evidence rated as fair. For all other management methods the evidence was judged to be incomplete. But the need for better determination of efficacy is acute, since much of modern preventive dental practice is predicated on the assumed efficacy of these methods.
Reference
Bader J, Shugars D, Bonito A. Diagnosis and management of dental caries: Evidence report, Vol 1 and 2. Rockville MD: Agency for Healthcare Quality and Research, RTI Project No. 6919-006 for AHRQ Contract No. 290-97-0011.