The epidemiology of root surface caries: North American studies.

After some problems resulting from the lack of standardized methods in the conduct of root caries studies and the lack of standardized reports of findings are reviewed, the prevalence and incidence of root surface caries in North America are reviewed through a combination of epidemiologic studies and large clinical trials. As part of this review, the available evidence on the relationship between root caries and missing teeth is presented. These data lead to the conclusion that the prevalence and, to some extent, the incidence of root caries are underestimated in adults with missing teeth. This review resulted in a number of observations regarding the status of root caries as an oral health problem. First, there is little evidence that would allow conclusions regarding the secular increase or decrease in the prevalence or incidence of root caries to be drawn. Other observations gleaned include the remarkably similar prevalence and incidence rates obtained from the studies reviewed, positive associations between root caries and age, negative associations between the prevalence and incidence of root caries and consumption of water containing fluoride, indications that root caries is a problem in adults with incidence rates that approach caries rates in children, and associations between the prevalence and incidence of root caries and a wide variety of oral, behavioral, and medical conditions. The final observation is the need for the acceptance of conventions for the definition of root caries as well as the reporting of findings in order for more firm conclusions to be drawn from future studies.