Incidence and progression of approximal caries from 11 to 22 years of age in Sweden: A prospective radiographic study

Using annual bite-wing radiographs, the incidence and progression of approx imal caries (4d-7m) were assessed longitudinally in teenagers and adolescen ts whose treatment had been based on remineralizing rather than restorative strategies. A closed cohort of 536 children initially was followed from 11 to 22 years of age. The scoring system was: 0 = no visible radiolucency; 1 -2 = radiolucency in the enamel up to the enamel-dentin border; 3 = radiolu cency with a broken enamel-dentin border but with no obvious progression in the dentin; 4 = radiolucency with obvious spread in the outer half of the dentin, and 5 = radiolucency in the inner half of the dentin. Caries rates were estimated as the number of new lesions/100 tooth surface-years, and th e Kaplan-Meier estimate was used to calculate the cumulative survival time of each approximal surface. Three events were used: the transitions from st ates 0 to 2, 2 to 4 and 3 to 4, The results showed a considerable variation between the surfaces in both caries rates and survival time. For all surfa ces combined, the median caries rate from state 0 to 2 was 3.9 new lesions/ 100 tooth surface-years; from state 2 to 4, the rate was 5.4, and from stat e 3 to 4 it was 20.3. Of the sound surfaces (state 0), 75% survived 6.3 yea rs without reaching state 2. Given state 2, 75% survived 4.8 years without reaching the outer half of the dentin (state 4), while given a lesion at th e enamel-dentin border (state 3), 75% survived 1.3 years without doing the same. The median survival time of lesions from state 3 to 4 was 3.1 years. The group with DMFSappr>1 at the age of 11-12 years had a risk of new appro ximal enamel lesions (state 0-2) that was 2.5 times greater than that of th e group with DMFSappr = 0-1.