The prevalence of overhang and gap formation in posterior amalgam and composite restorations among 4th and 5th stage undergraduate students/Tishk University

Abstract

Background: Overhanging approximate restoration may cause gingival aggravation periodontal tissue devastation, diminishes alveolar bone height, and recurrence of caries.Gap formation from margin of restoration may cause food impaction which leads to caries recurrence and if it happens inside restoration it will lead to weakening of restoration. Aims of the Study:The present study aims to assess the overhang and gap formation frequency in patients who visited the dental clinic of Tishk University of Medical sciences/conservative department for 4 th and 5 th grade undergraduate course. Materials and Methods:A random sample was collected from patients required class II restorations attending conservative department/dentistry college/Tishk University according to questionnaires which have been made for 4 th and 5 th grades that include personal information and type of restorative material which has been used, radiographs were taken (posterior bitewing) utilizing paralleling technique, then viewed on computer and change pictures' contrast, printed out and bound with its own questionnaire.Statistical analysis was done using chi-square test at P < 0.05 to find out the relationship.Results: There was a statistically significant association between overhang and the following parameters: gender of clinician, type of tooth, type of restoration at P < 0.05 level, while non-significant difference was found between overhang and following parameters; student's grade, gender of patient, location of tooth in jaw, and side of restoration at P > 0.05 level.For Gap Formation: There was a statistically significant association between gap formation and the following parameters: location of tooth in jaw, side of restoration, and type of restoration at P < 0.05 level.While there were non statistically significant relationships between gap formation and the following parameters: student's grade, gender of patient, gender of clinician, and type of tooth at P > 0.05 level. Conclusion:According to the present study, 20% of all surfaces that have been restored showed presence of overhang while (80%) were free from overhang, in relation to gap formation (25.6%) of restorations have gap formation while (74.4%) were free.