Changes in the epidemiologic pattern of dental caries in a Danish rural community over a 10-year period

A number of reports during recent years have suggested that dental caries is decreasing in several populations. In order to substantiate this, recordings of dental caries collected over a 10-year period were analyzed. All children received systematic preventive and restorative care from kindergarten to 9th or 10th grade (age approximately 16 years). Each cohort consisted of 50-60 children, and data on dental caries were available on all children in 1st through 7th grade over a 9-year period. Mean DMFS had decreased with 72% for 1st graders, 65% for 4th graders and 69% for 7th graders. Analyses of the distribution of children according to DMFS showed that in spite of the general decrease in mean DMFS, some children still showed high DMFS-values. The variability according to DMFS was increased during the same period as indicated by the coefficient of variation. Furthermore, children with a given, high DMFS account for a decreasing fraction of all DMF-surfaces in the population as the mean DMFS decreases. It is suggested that the effect on mean DMFS for the entire group of children of a hypothetical, individualized preventive program for high-risk individuals would be limited. In the light of these findings the appropriateness of special preventive programs for "high-risk" individuals is questioned.