Alveolar bone destruction due to overhanging amalgam in periodontal disease.

Interproximal bone loss around 100 teeth with overhanging amalgam restorations was measured and compared to interpoximal bone loss around 100 contralateral teeth without overhanging amalgams. The latter served as controls. Overall, bone loss was found greater around teeth with overhangs (P < 0.01). This finding was true for all periodontal disease types. However, the more severe the periodontal disease the greater the role of the overhang appeared. Small overhangs, unlike medium and large overhangs, did not result in increased alveolar bone loss around the affected tooth.