[Decrease in interdental bone atrophy, radiological survey; statistics from the years 1963-1976 from a Basel public dental clinic].

The material of this study consisted of 300 patients 16 to 39 years of age of the Public Dental Clinic of the City of Basle without destructive periodontal disease. The distance from the cementoenamel junction to the alveolar septum (DJS) was measured on bitewing radiographs at 8 surfaces of the lateral segment. On the radiographs made during the period 1963-1967, the average DJS ranged between 0.93 and 1.49 mm in the 5 age groups. Since 1964-1967, patients have routinely been given theoretical and repeated practical training in prevention of caries and periodontal disease. On the radiographs made during the period 1973-1976, the range of the averages was from 0.65 to 1.01 mm. The decrease of the DJS, 0.35 mm on average, was statistically significant in all 5 age groups.