Prevalence of overhang in tooth - colored restorations conducted in operative department of Shahid Beheshti dental school:2001-2002

Because of the importance of perfect and complete restorations in health of supporting tissues, this study was conducted to determine the prevalence of overhang in tooth–colored restorations which have been treated in operative department of Shahid Beheshti dental school during the year 1380-81. Methods & Materials: This was a descriptive study, done on 350 patients by undergraduate (9 and 10th semesters) and post graduate students in operative department of Shahid Beheshti dental school. Evaluation of overhangs were assessed according to grade of students, type and cavity surfaces, location of overhangs in relation to gingival margin, by means of observation, standard explorer and dental floss detection. In necessary cases, radiography was used for diagnosis. Chi – square test was used for statistical analysis. Fifty two percents of all restorations had overhangs (10.9% Cl II, 15.2% Cl III, 17.5% Cl IV, 8.4% Cl V), which 22.8% of them were treated by students of 9th semesters, 28.2% by students of 10th semesters, and only 1% by post graduate students. In this study, proximal surfaces, Cl IV cavities and restoration at gingival level and among undergraduate students had more overhangs.