The impact of PEEK pretreatment using H2SO4, riboflavin, and aluminum trioxide on the extrusion bond strength to canal dentin luted with Polymethyl methacrylate and resin-based composite cement.

Objective: To evaluate the effects of various surface pretreatment methods, including H2SO4, Riboflavin, and Al2O3, as well as different luting cement types, namely Methyl Methacrylate based Cement (MMBC) and composite-based cement (CBC), on the extrusion bond strength (EBS) of poly-ether-ether-ketone (PEEK) posts bonded to canal dentin.

Materials And Methods: This study involved 120 single-rooted human premolar teeth that underwent endodontic treatment. Following root canal preparation, PEEK posts were fabricated from PEEK blanks using a CAD-CAM system, resulting in a total of 120 posts. The posts were randomly assigned to one of four groups based on their post-surface conditioning: Group A H2SO4, Group B RF, Group C Al2O3, and Group D (NC), each consisting of 30 posts. Within each group, there were two subgroups based on the type of luting cement used for bonding. Subgroups A1, B1, C1, and D1 (n=15 each) utilized CBC, while Subgroups A2, B2, C2, and D2 (n=15 each) used MMBC.The bond strength between the PEEK posts and root dentin was assessed using a universal testing machine, and the failure modes were examined under a stereomicroscope. Statistical analysis, including one-way analysis of variance (ANOVA) and Tukey's Post Hoc test with a significance level of p=0.05, was performed to analyze the data and evaluate the effects of surface treatment and luting cement type on the bond strength.

Results: Group B2, which underwent RF conditioning followed by Super-Bond C&B cement application, exhibited the highest bond strength scores at the coronal section (9.57±0.67 MPa). On the other hand, Group D1, which had no conditioning (NC) and used Panavia® V5 cement, showed the lowest EBS at the apical third (2.39±0.72 MPa). The overall results indicate that the different conditioning regimens and luting cement types did not significantly influence the bond strength of PEEK posts to root dentin (p>0.05).

Conclusions: Riboflavin activated by photodynamic therapy (PDT) and H2SO4 can be effective surface conditioners for PEEK posts. These treatments have shown potential for enhancing the bond strength between PEEK and resin cement. Additionally, the study revealed that MMA-based cement outperformed composite-based cement in terms of bond integrity with PEEK posts.