Placement and longevity of amalgam restorations in Denmark

A survey has been made of the reasons for placement of 4932 amalgam restorations in Denmark. In patients more than 16 years of age 39% of all restorations were made because of primary caries, and 61% were replacements of failed restorations. In children 74% of the restorations in primary teeth and 84% of those in permanent teeth were inserted because of primary caries. The reasons for replacement of restorations depended 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 and accounted for 38% of all failures. Marginal discrepancies and bulk fracture of fillings were the other two major reasons. In primary teeth fracture and loss of fillings were the commonest reasons, whereas secondary caries accounted for only a quarter of all restorations replaced. The age of the restorations replaced ranged from 0 to 46 years, and half of the failed restorations in permanent teeth of adults were more than 8 years old. A shorter longevity of failed restorations was noted in primary teeth and permanent teeth of children.