RESUMEN
To determine the frequency of overhanging margins in amalgam restorations done by undergraduate students at Fatima Jinnah Dental College Hospital, Karachi. Observational study. Department of Operative Dentistry, Fatima Jinnah Dental Hospital, Karachi, from January to June 2009. Patients aged 20 - 45 years attending the Department of Operative Dentistry requiring class-II restorations were included in the study. Whereas, third molars, overlapped proximal surfaces, teeth adjacent to edentulous spaces and pregnant females were excluded. One hundred and fifty patients were selected randomly aged between 20 - 45 years requiring class-II restorations. Posterior Bitewing radiographs were taken and 1600 surfaces were examined. Restorations were done by undergraduate students at Fatima Jinnah Dental College Hospital, Karachi. Chi-square test was utilized to analyze the relationship between location and surface of overhang. Overhanging amalgam restorations were common in the restorations done by undergraduate students [58%]. The occurrence of overhangs was more frequent on the distal surfaces [56%]. Although the association of amalgam overhangs with the surfaces of the teeth was significant [p < 0.0001], overhangs were not significantly associated with the location of the teeth [p < 0.063]. Overhanging restorations were present in approximately 58% of all proximal amalgam restorations done by undergraduate students