فراواني بيرون زدگي پروگزيمالي در ترميمهاي آمالگام خلفي انجام شده توسط دانشجويان دندانپزشكي تبريز

PrevaJence of Proximal Overhanging margins in Posterior Amalgam Restorations Performed by Tabriz Dental Faculty Students

Background and Objectives: The existence of overhang in the amalgam restorations has many adverse effects on the health of periodontal tissues. The purpose of the present study was to assess the amount of prevalence of proximal overhang in the amalgam restorations performed by students of the operative department of Tabriz faculty of dentistry in the year of 2006-2007. Materials and Methods: In this descriptive and sectional study 400 patients who had referred to the operative department of Tabriz faculty of dentistry were the population under assessment. They were selected randomly and posterior amalgam restorations were performed for them by the students of 7th, 10th and 11 th semesters. The data about the existence of proximal overhang in terms of the restoration type and educational semester of the students were collected first by a sharp probe and then by using bite-wing radiography by the consent of the patient. Chi -square test was used for analyzing the data (a=0.05). Results: The overall prevalence of the overhang was obtained 25.7%.Respectively 15.6%, 32% and 28% of the performed restorations by the students of 7th, 10th and 11th semesters had overhang. 23.5% of the mesioocclusal/distoocclusal restorations, 23% of mesioocclusodistal restorations and 29.4% of the build-ups had overhang. More percentage of overhangs (68.94%) was distinguished by combinations of clinical and radiographic evaluation. There was a statistically significant relationship between studentsʹ educational semester and presence of overhang (p=0.031), while the association between restorationsʹ type and overhang was not significant (p=0.39). Conclusion: The prevalence of overhang was relatively low in the restorations performed by the students of Tabriz faculty of dentistry. Furthermore the most precise method for overhang assessment was using the combination of the clinical examinations by the use of probe and bite- wing radiography.