Fracture resistance of endodontically treated teeth restored with CAD-CAM milled and prefabricated post-and-core systems.

Purpose: To compare the effect of post-and-core material type and production technique on the fracture resistance of teeth.

Materials and methods: Sixty human maxillary central incisors were used for the study. Root canal treatments were performed, and the post cavities were created. The teeth were divided into six groups (n = 10) according to post material and production method: prefabricated glass-fiber post (PF), zirconia post (PZ), titanium post (PT), and CAD-CAM produced glass-fiber post (CF), zirconia post (CZ), titanium post (CT). All post-and-core restorations were luted with resin cement (RelyX U200). Static loading was applied on the luted metal copings using a universal testing machine to measure fracture resistance. The effect of material and production method on fracture resistance was evaluated with two-way ANOVA test. Tukey HSD test was used in post hoc analyses. Significance was evaluated at p < 0.05 level.

Results: In the CAD-CAM post-and-cores, the fracture resistance of zirconia was significantly higher (809 N) than titanium (569 N) and glass-fiber (342 N). In the prefabricated posts, the fracture resistance of zirconia was significantly higher than glass-fiber (445 N), while there was no significant difference between zirconia (605 N) and titanium (538 N) materials.

Conclusion: Zirconia posts demonstrated the highest and CAD-CAM glass-fiber posts demonstrated the lowest fracture resistance compared to other types of post materials. Additional studies are needed to confirm if CAD-CAM glass-fiber posts may be considered an effective alternative treatment.