Root caries in Scandinavia in the 1980's and future trends to be expected in dental caries experience in adults.

The large variety of diagnostic criteria used adds some uncertainty to comparisons of recent clinical and epidemiological data on root caries in Scandinavia. Nevertheless, it is apparent that the prevalence of frank carious cavities on the root among 60(+)-year-olds is about 30-40%. When inactive and recurrent lesions and fillings are included, the prevalence is almost 100% in 60(+)-year-olds. At this age, the mean number of root surface fillings is about 7, and the mean number of active caries lesions ranges from 0.9 to 3.4. The degree of gingival recession does not appear to be a direct measure of root caries risk in a population. When the number of teeth at risk is accounted for, the age-dependent increase in prevalence of root caries is very weak. Therefore, comparisons of root caries prevalence between populations are meaningful only when information on number of teeth present and teeth at risk is also available. Recent studies from various parts of the world have demonstrated that caries is ubiquitous in all populations and that caries progression continues throughout life. The impact of this on trends in prevalence and incidence of dental caries in adults is discussed in the light of what is known about the natural history of dental caries.