Approximal Caries Prevalence in Danish Recruits and Progression of Caries in the Late Teens: A Retrospective Radiographic Study

Abstract

This study aimed to assess radiographically the prevalence and distribution of approximal caries in Danish recruits and to estimate the rate of caries progression during the recruits’ late teens. To assess caries progression radiographs taken previously (when leaving the Public Dental Health Care Service, usually at the age of 16–18) were requested. Of 676 recruits previous radiographs (taken 1–7 years earlier) were procured for 640. Approximal surfaces from 7d to 4m in the maxilla and the mandible were assessed for the absence or presence/ depth of caries and restorations. Caries progression was expressed by the incidence rate indicating the number of new lesions/number of lesions with progression per 100 years. In the maxilla the average prevalence of enamel and dentine caries was 8.3 and 6.2%, respectively. Overall, 6m had the highest caries experience. In the mandible the average prevalence of enamel and dentine caries was 10.7 and 5.8%, respectively. The highest caries experience was found in 6d. Twenty percent of the recruits had no caries experience in the surfaces under study, 9% had caries experience in 1 surface, 13% in 4–5 surfaces and 25% in more than 10 surfaces. For all surfaces combined, the median incidence rate for the transition from sound to enamel caries was 2.4 surfaces per 100 years, ranging from 0.4 in mandibular 7d to 5.5 in mandibular 6d. The median rate for progression from the enamel to the outer half of the dentine was 9.2 surfaces per 100 years, ranging from 4.4 in mandibular 5m to 18.9 in mandibular 6d. The median incidence rate for progression from the outer to the inner half of the dentine was 2.3 surfaces per 100 years. However, this figure was based on a small number of events and should therefore be interpreted with caution. In conclusion, enamel and dentine caries was found in 9 and 6% of the approximal surfaces in newly called up recruits, and one quarter of the recruits had caries experience in more than 10 approximal surfaces. Generally, the development of new approximal lesions and the progression of enamel caries was a slow process during the late teens.