بررسی استحکام شکست کاسپی دندان‌های پرمولر ماگزیلای ترمیم‌شده به پنج روش مختلف

Introduction:Various methods are applied in order to restore maxillary premolar teeth which show much decay, though some inconsistencies have been reported in regard with the rate of fracture strength in different studies. Therefore, in this study, fracture resistance of buccal cusp was compared via 5 different types of restorations. Methods: In this experimental study, 75 intact extracted maxillary premolars were used and divided into 5 groups. Standard MOD cavity with reduction of pulpal cusp was prepared in all groups and then was restored with different methods. The teeth were randomly divided into Group A: amalgam build-up with one pin, Group B: amalgam build-up with two pins, Group C: composite build-up , Group D: composite build-up with fiber(FRC) and Group E: ceramic onlay. The specimen were assessed via Universal Testing Machine in order to examine fracture resistance. In order to analyze the study data, Mann- Whitny and Kruskal Wallis tests were utilized to make the comparison among five types of materials. Results:There was a high significant difference among all the groups. The average fracture resistance values were as follows: group A 236.19 N, group B 289.81 N, group C 333.07 N, group D 459.31 N and group E 165.04 N. Conclusion: Regarding the higher cuspal fracture resistance in group D, it can be definitely possible to apply this method to restore destructed and carious maxillary premolar teeth with more reliability.