Evaluation of Fracture Resistance in Maxillary Premolar Teeth Restored with Different Direct Composite Restorative Material

Purpose: This study was conducted to evaluate the effect of three direct resin composite restorative materials on fracture resistance in mesio-occluso-distal (MOD) cavities prepared in maxillary premolars. Materials and Methods: A total of 25 maxillary premolars were collected and then divided into five main groups (n=5). Group 1 (positive control group): sound teeth with no cavity preparation. Group 2 (negative control group): MOD cavities with no restoration. Group 3: MOD cavities restored with nanocomposite FILTEK™ Z350 XT Group 4: MOD cavities restored with simplified universal composite OptiShade™ and Group 5: MOD cavities restored with universal nano-filled composite Estelite® Sigma Quick. Results: Group 5 showed the maximum fracture strength value (ranged from 1170-1355 N) followed by Group 4 (998.1- 1158 N) then Group 3 (900.9-1097 N) followed by Group 1 (positive control) with fracture strength value ranging from 836.1 to 1059 N. Group 2 (negative control) showed the minimum fracture strength value ranged (380.6-631.6 N). For the significance evaluation of different groups, One-Way ANOVA was performed followed by Tukey`s post hoc test for multiple comparisons which revealed all significant differences between different groups as P-value < 0.05 except for (group 1 # group 3), (group 1 # group 4) and (group 3 # group 4) respectively which were insignificantly different as P-value > 0.05. Conclusion: Reinforcement of the teeth could be achieved after MOD cavity preparation in maxillary premolars through proper restorative procedures.