Comparison of fracture strength of cad/cam and prefabricated post systems

Method: In the present study, 60 human maxillary central incisors were used, which were extracted for orthodontic or periodontal reasons, have no fractures or cracks, are free of caries, have no restorations, and have no hypoplastic defects. These teeth were divided into 6 groups (n=10). The teeth were separated from their roots 2 mm above the cemento-enamel border. As a result of the decoration process, a 1 mm wide shoulder step was created on the teeth and a 2 mm high ferrule was obtained. Afterwards, root canal treatment was applied to the teeth. Post cavities of 9 mm depth were created in all teeth with 1.4 mm diameter drills. In the present study, post core groups were created from 6 groups; Prefabricated Glass Fiber Post, Zirconia Post, Titanium Post, CAD/CAM produced Glass Fiber Post Core, Zirconia Post Core, Titanium Post Core. All post-core restorations were cemented with dual cure composite resin cement. Composite resin core was applied for prefabricated posts. Metal copings were created for each specimen, cemented with dual cure composite resin cement. The specimens were embedded in acrylic resin blocks, then the specimens were heat cycled 5000 times (5-55 degrees) and static loading was applied at an inclination of 45 degrees to the long axis of each tooth using a Universal testing machine to measure fracture strength. Results: According to the statistical analysis results, a significant difference was found between the groups in terms of mean fracture strength. In the groups of CAD/CAM, the fracture strength of zirconia material was found to be significantly higher (809N) than Titanium (569N) and Glass Fiber (342N). In the form of prefabricated production, the fracture strength of zirconia material was found to be significantly higher than Glass Fiber (445N), while there was no significant difference between Zirconia (605N) and Titanium (538N) material. Conclusion: In the present study, Zirconia Posts were found to be the most resistant group in terms of fracture strength in both production forms, while Glass Fiber Posts were found to be the least resistant group. Production method and material together affect the fracture strength.