Evaluation the Overhang Rate in Class II Amalgam Restorations among Bandar Abbas Patients in 2015

Overhang in tooth restoration not only increases dental plaque size, but also is responsible for deterioration of periodontal tissues due to environmental changes and the imbalance in the equilibrium between beneficial bacteria and pro-pathogen plaque they cause. Aim of this study is to evaluate the prevalence of overhang in class II amalgam restoration in patients referred to Bandar Abbas dentistry faculty. This study was designed as a cross sectional study. Patients referred to Dentistry faculty of Hormozgan University of Medical Sciences with at least one class II amalgam restoration in 2014-2015 first and second semesters were clinically examined and there radiographs were evaluated. Since using radiographs and clinical examination is one of the most reliable methods to diagnose overhang, both methods were used. Number and site of restoration, presence of absence of overhang and weather they were mesial or distal were recorded. Radiograph evaluation was performed twice by two students who should 95 percent homology in a pilot study under supervision of a restorative dentist. Then clinical examinations were performed and in necessary cases bitewing radiography were executed. Results showed that 22.2 percent of restorations presented overhangs from which distal, mesial, and distomesial overhangs included 7.1, 12.4, and 2.7 percent of overhangs respectively. Chi-square test was performed to analyses the relation between site and level of overhangs, results of which suggested that there is no relationship between dental site and presence of overhangs. Due to the importance of damages of overhang to dental tissue, it is suggested that principles of properly preparing the restorations be emphasized in dentistry instruction courses