Periodontal disease and approximal overhangs on amalgam restorations in Norwegian 21-year-olds.

The prevalence of periodontal disease and overhanging approximal amalgam restorations in molars and premolars was registered in a clinical and radiographic examination of Norwegian adults (born 1959). A random sample of 250 persons was drawn from the populations of two neighboring towns where the Public Dental Services had operated different preventive programs. Results pertain to approximately 175 subjects whose mean age was 21.5 yr (SD 0.3). Twelve subjects had no gingival bleeding and the mean Gingival Bleeding Index of the group was 30.8 (SD 17.6). No pocket depth exceeded 5 mm. In eight subjects the radiographic distance from the cementoenamel junction to the interproximal alveolar crest was greater than 2 mm at one or more teeth. The mean number of filled approximal surfaces in molars and premolars was 12.8 (SD 6.8). Approximal overhangs were present in 87% of subjects, and at 1/4 of restorations. Ninety-six percent of overhangs were less than 0.5 mm. There was no significant difference between the different subgroups of the sample for any of the variables studied.