The fate and survival of amalgam and preformed crown molar restorations placed in a specialist paediatric dental practice.

The fate of 1688 amalgam restorations and 716 preformed crowns placed in permanent and primary molars in a specialist paediatric dental practice over a 10-year period by one operator is reported. For primary molar amalgams, the replacement rate, true failure rate and 5-year survival estimates were, for Class 1 restorations, 16.1%, 3.9%, 73.3%, respectively, with an estimated median survival time greater than 8.5 years, and for Class 2 cavities 14.7%, 11.6%, 66.6%, with an estimated median survival time greater than 7.5 years. For permanent molar amalgams, the replacement rate, true failure rate and 5-year survival estimates were for Class 1 restorations 11.5%, 6.5%, 76.8%, respectively, with an estimated median survival time greater than 9.3 years, and for Class 2 restorations 9.8%, 8.0%, 82.2%, with a median survival time greater than 8.5 years. For all preformed crowns, the replacement rate, true failure rate and 5-year survival estimates were 2.8%, 1.9%, 92.0%, and the estimated median survival time greater than 7.64 years. No relationship was observed between the age of the patient and the age of replaced restorations. No significant difference was found between the survival rates of Class 1 and 2 amalgam restorations in primary or permanent molars, nor between first and second primary molars.