Journal of AdvancedMedical and Dental Sciences Research

Background: The effect of using zirconia (Zr) post in combination with Zr containing cores to restore teeth is not known. The aim was to investigate the failure loads of endodontically treated teeth restored with Zr post in combination with Zr containing core materials. Methods: Forty central incisor teeth were sectioned coronally and prepared with 1.5mm chamfer margin. Endodontic treatment was performed using step-back and cold lateral condensation techniques. Teeth were divided into four groups (each group, n=10) based on the combination of the post and cores used. The two core materials included were Zr nano-filler based bulk fill  and Zr free bulk fill. The post systems used were fiber post and Zr glass fibre post. An overall 5mm height core was made and controlled loads were applied at 135° to the occlusal surface until failure.  The failure modes and loads among different groups were compared using ANOVA and Tukey’s multiple comparisons test. Results: Maximum and minimum failure loads were observed for specimens in Group C (Zr glass post and Zr based core) (27.41) and Group B (Fibrepost  and Zr free core)(20.03) respectively. Failure loads among group C specimens were significantly higher (p<0.01) than specimens in groups A (Fibre post and Zr based core) and B. Failure loads in Groups D (Zr glass post and Zr free core) and A were significantly higher (p<0.01) than failure loads in group B. Among all groups, failures above CEJ were upto 80% and failures below CEJ were upto 40%. Conclusions: Endodontic-treated teeth when restored with Zr based post and Zr nano-particle core display higher failure loads as compared to fiber post and conventional resin core.
Key Words: Endodontic treated teeth, Failure loads, Resin core, Zirconia nano particle