Restorative treatment pattern and longevity of amalgam restorations in Denmark.

A survey has been made of the reasons for placement and replacement of 6052 amalgam restorations in Denmark. In patients more than 16 years of age 48% of all restorations were made because of primary caries, and 52% were replacements of failed restorations. In primary teeth 64% and in permanent teeth of children 83% of the restorations were made because of primary caries. The reasons for replacement of restorations were dependent on dentition, age of the patient, and type of restoration. Secondary caries was the most frequent reason for replacement of failed restorations in permanent teeth, comprising a third of all replacements. Marginal discrepancies and bulk fracture of fillings were the other two major reasons. In primary teeth fracture and loss of fillings were the two major reasons for replacement of amalgam restorations, whereas secondary caries caused less than a quarter of all restorations to be replaced. The age of the restorations replaced ranged from 0 to 38 years, and half of the restorations replaced in permanent teeth of adults were less than 7 years old. A shorter longevity of failed restorations was noted in primary teeth and permanent teeth of children.