Marginal failures of amalgam and composite restorations

Objective: The aim of the study was to clinically assess marginal failures of amalgam and composite restorations. Method: Marginal defects with and without clinical evidence of secondary caries were evaluated by practitioners pre-operatively and after the restoration had been carefully removed. Results: Analyses of 235 amalgam and 193 composite restorations with marginal failures showed that secondary caries was the most frequent diagnosis resulting in replacement. The secondary caries was predominately found along the gingival section of the restoration. A comparison of pre-operative diagnoses of marginal discrepancies, and the condition of the cavities at the site of the defects after the restorations had been carefully removed, showed fairly good consistency, but both false negative and false positive diagnoses were made. Conclusion: The observations indicated that diagnosis of the outer lesion of secondary caries provides a good basis for treatment planning.