Evaluation of fracture strengths of different restoration techniques on 3d teeth replicas with c shaped root canal structure

Aim: In this study it is aimed to evaluate the effect of different restoration techniques on fracture strength of endodontically treated C-shaped teeth replicas. Material and Method: CBCT datas of patients with prominent C-shaped root canal anatomy were examined. After 3D reconstruction of the chosen mandibular tooth, replicas were produced on 3D printer. Replicas were randomly divided into 7 groups. Group 1: Intact replicas(n=10) Group 2: Replicas restorated with resin composite(n=11) Group 3: Replicas restorated with bundle fiber post and resin composite(n=11) Group 4: Replicas restorated with vertically placed fiber post and resin composite(n=11) Group 5: Replicas restorated with horizontally placed fiber post and resin composite(n=11) Group 6: Replicas restorated with woven fiber post and resin composite(n=11) Group 7: Replicas restorated with composite endocrowns(n=11) All replicas were embedded into self-curing acrylic resin with mimicking the PDL. A static loading applied until failure by using universal testing machine. The results were recorded and statistically analyzed by using one way ANOVA, Monte Carlo Pearson Chi-Squared, Pearson Chi-Squared and Fisher's Exact Tests (p<0.05). Results: There was a difference between fracture resistance of all groups (p = 0.001). Group 6 showed the highest fracture resistance values whereas there was no statistically significant difference between Group 4. In terms of fracture type, Group 7 showed the highest percentage of repairable fractures (100%). Conclusion: The highest fracture resistance was recorded for woven fiber post group and endocrown restoration group. Considering the restorability of replicas, endocrown restorations could be recommended for teeth with C-shaped root canal structure.