Differences between primary and permanent teeth in posteruptive age dependency of radiological changes in enamel during the development of approximal caries.

A longitudinal radiological study of children (N = 549) who participated in a comprehensive preventive maintenance program showed that caries related events in the approximal surfaces of permanent teeth differed from those in deciduous teeth. Changes in the approximal surfaces of the younger permanent teeth were more pronounced than of the older primary teeth and differed significantly from 1 year to 2.5 years. These findings can be explained by posteruptive maturation of tooth enamel.