Effect of Surface Treatments of Polyetherketoneketone as a Post Material on Shear Bond Strength to Root Dentin using Two Types of Resin Cement.

Purpose: This study investigated the effects of mechanical and chemical pretreatment of polyetherketoneketone (PEKK) on shear bond strength (SBS) to root dentin using two types of resin cement.

Materials and methods: A total of 100 PEKK specimens were prepared and polished. Sixty specimens were mechanically treated by sandblasting (50-µm Al2O3 for 10 s at 0.2-0.25 MPa), and the remaining 40 were untreated. Self-adhesive resin cement and conventional resin cement were used. PEKK specimens bonded to root dentin using self-adhesive resin cement were classified into three groups by pretreatment method: (1) untreated PEKK, (2) mechanical pretreatment (sandblasted PEKK), and (3) both mechanical and chemical pretreatment (PEKK sandblasting as well as application of Scotchbond Universal; 3M Oral Care). Conventional resin cement was pretreated following the same steps (1-3) as those followed for self-adhesive specimens. Each group included 10 specimens. PEKK specimens after surface treatments were examined using SEM. SBS tests were performed using a universal testing machine, and data were statistically analyzed using one-way ANOVA and Tukey's multiple comparison test (p < 0.05).

Results: No significant difference was observed between cements with and without sandblasting. However, self-adhesive specimens with both mechanical and chemical pretreatments demonstrated higher SBS than other cements with or without pretreatment.

Conclusion: Mechanical pretreatment by sandblasting did not improve the PEKK-root dentin SBS. However, combined mechanical (sandblasting) and chemical pretreatment (ScotchBond Universal) significantly improved the SBS between the PEKK and root dentin.