RESUMEN
The purpose of the study was to investigate the reasons for the failure of Class I and II amalgam restorations in patients presenting at the Operative Department of Fatima Jinnah Dental College and Hospital. Sample of 100 patients was clinically evaluated to assess the reasons for the failure of amalgam restorations. Information regarding the patients' age, gender, presenting complaints, and reasons for the failure was collected for conducting this study. Results revealed that the most common reason for the failure and replacement of amalgam restorations was secondary caries, followed by inadequate resistance form. It was concluded that the prevailing reason for the failure of restoration is secondary caries which may be as a result of incomplete caries removal and non-retentive cavity preparations