The study was designed to compare the prevalence of marginal bone loss in 2 cohorts of 16-year-old adolescents, born in 1959 and 1972, respectively. Bitewing radiographs from 400 adolescents in each group were evaluated and the presence of bone loss (distance between the cemento-enamel junction and the alveolar crest greater than 2 mm), calculus, restorations and proximal dental caries were recorded. The prevalence of bone loss was 3.5% in 1975 as well as in 1988. Bone loss was found most frequently at the mesial and distal surfaces of the first maxillary molar. The prevalence of calculus was 12% in 1975 and 7% in 1988. The mean DFS for proximal surfaces was 3.1 in 1975 and 0.8 in 1988. No statistically verified dependence was found between bone loss and calculus, or bone loss and proximal caries.