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NIH: Consensus Development Conference on Diagnosis and Management of Dental Caries Throughout Life: Background

NIH organized conference that produced consensus statements on important and controversial topics in medicine and dentistry.

Clinical Decision-Making for Caries Management in Root Caries

James L. Leake, D.D.S., M.Sc., DDPH, FRCD(C):

This is a review of studies on diagnosing, predicting, and intervening in the disease known as root caries that may help clinicians communicate information for their decisions on care to patients.

Questions Addressed in This Review

  1. What is the natural history of root caries among North American populations? Natural history in this case includes definitions of lesions at different stages; the activity of lesions (active, inactive); rate of progression from stage to stage; reversibility under natural conditions of lesions, by stage; and outcome of untreated root caries.
  2. How accurate and reliable are the methods we have to diagnose active and inactive root caries?
  3. For persons with root caries, are there differences in outcomes (absolute improvement in number of teeth retained and functional, or relative improvement, or number needing treatment) between subjects randomly assigned to receive therapeutic care and those not receiving such care?

Search Strategy

A search strategy was developed by a consultant to the project, and searches of EMBASE and MEDLINE resulted in a database of 807 annotated references. The annotated references were read independently by at least two people to achieve consensus on 94 that were selected for retrieval. The reference lists in those 94 were then checked, and studies that appeared to be related to our questions were added, producing a final database of 162 references.

Ideally, the evidence should have been selected from high-scoring studies with strong design, as described in criteria of the Agency for Health Care Policy and Research (AHCPR). Many studies, however, were both weak in design and of limited value. Since the evidence on management of root caries is rarely supported by more than a few studies, recommendations on how to do so can only be tentative.

Findings on Prevalence

Prevalence estimates of root decayed and filled surfaces (RDFS) were taken from the NHANES III study. The adjusted prevalence for U.S. adults, as measured by those with one or more lesions, was 25.1 percent. Prevalence increased with age, and by age 75, 55.9 percent had one or more lesions. Severity as measured by the mean number of RDFS was 1.2, of which 58.3 percent were filled. As expected, severity was also age-dependent. Women had lower prevalence (23.3 percent vs. 27.1 percent), lower mean scores (1.0 vs. 1.4) and lower proportions filled (50.0 percent vs. 64.3 percent) than men. Among patients age 34 and older, the prevalence was roughly 20 percent less than a person's age. For example, a person age 50 would have a 30 percent probability of having one or more RDFS.

Findings on Incidence

Eight papers met the inclusion criteria for determining the incidence of root lesions (Hand, Hunt, Beck, 1988a; Hand, Hunt, Beck, 1988b; Leske, Ripa, 1989; Wallace, Retief, Bradley, 1988; Lawrence, Hunt, Beck, 1995; Lawrence, Hunt, Beck, et al., 1996; Locker, 1996; Powell, Leroux, Persson, et al., 1998). These eight discussed five different investigations (two of the studies each discussed two papers). The studies that lasted 16 to 18 months showed much higher incidence estimates that did the studies lasting 3 years or more. Calculation of a duration/sample-size weighted estimate from the results of the four longest studies showed that 8.2 percent of study subjects would be expected to acquire one or more new root caries in 1 year. Those four studies plus one other showed that, on average, dentate people would be expected to acquire 0.19 new RDFS per year.

Clarkson (1995) added a cautionary note when she pointed out that conventional studies of incidence would not pick up restorations of secondary root caries, leading to an understatement of the actual incidence of lesions by as much as two-thirds.

Description of Root Caries Lesions

Diagnosis of a root caries lesion is established through the use of clinical descriptors. These vary, and are subjective. Clinical description is based on color, texture, surface smoothness, depth of the lesion, and distinctiveness of its border, overlayed with a judgment on whether the lesion is active or inactive. Variability in the diagnostic criteria, and the question of whether restored roots are included, strongly affect estimates of the prevalence and severity of root caries lesions (Katz, 1980; DePaola, Soparker, Kent, 1989; Aherne, O�Mullane, Bennett, 1990; Stamm, Banting, Imrey, 1990; Banting, 1993; Fejerskov, Baelum, �stergaard, 1993). The variability in diagnostic criteria limits validity because lesions which apparently "reverse" can be either true reversals or examiner error (Lawrence, Hunt, Beck, et al., 1986; Beck, Lawrence, Koch, 1995).

Katz (1986) defined active and inactive lesions, but that was a statement of consensus.

Severity Index

Billings (1986) developed a staging classification, termed a "severity index," of root caries lesions as follows: Grade I (incipient), Grade II (shallow), Grade III (cavitation), and Grade IV (pulpal). This index, however, was not derived from longitudinal studies of the same teeth in the same individuals.

Diagnostic System

Five articles provided material for the evidence table on diagnostic systems. The evidence indicates that practitioners have little alternative but to use systems for diagnosing root caries lesions that have low reliability and whose accuracy is unknown. While there is little to recommend any one system over the others, the texture (soft/hard) components of the Billings (1985) and the Hellyer (1990) systems have at least been shown to correspond to histopathology findings (Schupbach, Guggenheim, Lutz, 1990) and penetration by micro-organisms (Beighton, Lynch, Heath, 1993).

Therapy for Root Caries

Seven studies that dealt with remineralization of a tooth with a root caries lesion are included in the evidence table (Billings, Brown, Koster, 1985; Wallace, Retiel, Bradley, 1993; DePaola, 1993; Schaehen, Keltjens, Van Der Hoeven, 1991; Emilson, Ravald, Birkhed, 1993; Johansen, Papas, Fong, et al., 1987; Nyvad, Feyerskov, 1986). The available evidence supports remineralizing with fluoride rinses and, somewhat more tentatively, with fluoride gels and varnishes or chlorhexidine varnish. Also offered as a treatment option was recontouring before remineralizing with fluoride. However, the efficacy of recontouring followed by fluoride treatment was only demonstrated in six people with a total of 13 lesions.

Evidence on restoration of lesions is even more tentative. No studies were found that compared methods of restoring root caries over what would be considered a sufficiently long term. Of the four studies in the evidence table (Billings, Brown, Koster, 1985; Levy, Jenson, Doering, et al., 1989; Duke, Robbins, Snyder, 1991; Sheth, Lesen, Wefel, et al., 1988), the longest was 3 years in duration; the only controlled comparison ran for 1 year. The very limited data suggest that dentists may restore root caries with composite resins, although conventional practice may allow glass ionomer or even amalgam restorations (though no studies are listed).


Generally, studies on the management of root caries do not offer strong evidence on how to care for patients. They are few in number, and they are compromised either in design or duration. The literature is so limited that the issue of which approaches might be more appropriate in terms of patient preference, costs, and efficiency cannot be addressed. Research is needed to validate the accuracy of current diagnostic methods, provide evidence on the efficacy of therapeutic measures through more rigorous designs extending over longer periods, and address the issue of patient-based measures of outcomes.


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Schaeken MJ, Keltjens HM, Van Der Hoeven JS. Effects of fluoride and chlorhexidine on the microflora of dental root surfaces and progression of root-surface caries. J Dental Res 1991;70:150�3.

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Abstracts Index