Caries behaviour in Danish teenagers: a longitudinal radiographic study.

Coinciding with the decline in caries prevalence observed among children and adolescents, changes in the distribution and progression rates of the disease have been found. The aim of this study was to assess occlusal and approximal caries behaviour and disease distribution within a group of Danish teenagers, and to determine whether the presence of occlusal fillings at baseline could be used as predictor for caries behaviour. The material used was bitewing radiographs taken twice in 197 adolescents, at the age of 14.5 years (first examination) and approximately 3 years later (second examination). Of the occlusal surfaces assessed at both examinations, 93% remained unchanged, 1% developed new carious lesions, and 6% had been filled during the study period. All occlusal dentinal lesions found at the first examination and left unrestored during the study period did not appear to have progressed. Of the approximal surfaces, 86% remained unchanged, 9% developed caries, 2% showed caries progression, and 2.5% had been filled during the study period. 22% of the approximal enamel lesions found at the first examination progressed into the dentine during the study period. 18% of all the children were responsible for 50% of the total number of new lesions and fillings. The proportion of children exhibiting new lesions at the second examination was almost evenly distributed among children with and without occlusal fillings at the first examination. In the group of children with occlusal fillings at baseline, significantly more individuals than in the other group showed new fillings and lesions with and without progression. It is concluded that the progression percentage for approximal enamel lesions to penetrate into the dentine was low, that the distribution of new carious lesions and fillings among the children was polarized, and that the presence of occlusal fillings at baseline could not be used to identify children with a specific caries behaviour.