Placement and replacement of amalgam restorations in Germany.

From 15 September to 15 October 1991, 102 dentists practicing in a rural area of Germany provided information on 5240 amalgam restorations. The aim of the present cross-sectional study was to investigate the reasons for placement and replacement of amalgam fillings and to register the age of the failed restorations. First placements because of primary caries were made in 47.1% of all cases; 52.9% were replacements of failed restorations. The most frequently recorded reason for replacement was secondary caries, irrespective of size of the filling, dentition, and age group. The second most frequently recorded reasons for replacement depended on the size of the filling, the age and the dentition of the patient: Bulk fractures were predominant in primary teeth and in fillings with three or four surfaces, primary caries in permanent teeth of patients 16 years old or younger and marginal gaps in adults and in fillings with one or two surfaces. The median age of replaced amalgam restorations in adults was 60 months.