Surface-specific caries incidence in permanent molars in Danish children.

Clinical data on caries incidence rates based on a long follow-up period are scarce in the dental literature. The purpose of the present study was to describe caries incidence rates in first and second permanent molars in Danish children. The study was based on data reported to a central national registry maintained by the Danish National Board of Health. From this registry, records from more than 50,000 children born in 1980 and followed for 12 to 15 yr were used. Data on first and second molars were analyzed at both tooth and surface level using non-parametric methods for interval-censored data. Caries incidence rates rose slightly as a function of age for both first and second molars during the entire follow-up period. The observation made earlier by others, of a peak in caries incidence rates 2 to 4 yr after emergence, was not confirmed by the present study.