Resin Bond Strength to Polyetheretherketon (PEEK) Using Different Surface Treatments

Objectives: The purpose of the study was the evaluation of the adhesive bond strength of a provisional resin to a polyetheretherketon (PEEK) using different surface treatments and conditioning methods. Methods: PEEK discs were polished with 600 grit rotating silicon carbide papers. Plexiglas tubes were filled and bonded with a provisional resin (Luxatemp Fluorescence, DMG, Hamburg, Germany) to the PEEK disk which were air-abraded either 110 µm alumina particles at 2.8bar (Pre; Rocatec Pre, 3M Espe, Seefeld, Germany) or tribochemically silica-coated at 2.8bar (Plu; Rocatec Plus, 3M Espe). No primer (NO) or one of the following primers was used for conditioning: Ecusit Composite Repair (ECU; DMG), Luxatemp Glaze&Bond with a residence time of 5 minutes (LGB; DMG), Espe Sil (SIL; 3M Espe) and Clearfil Ceramic Primer (CCP; Kuraray, Osaka, J). The following test groups with 16 specimens each were bonded: Pre-NO, Pre-ECU, Pre-LGB, Pre-CCP, Plu-SIL, Plu-CCP. Subgroups of 8 specimens each were stored in distilled water at 37°C either for 3 days without thermal cycling (TC) or for 150 days with additional 37,500 thermal cycles between 5 and 55°C (dwell time 30s). Following storage tensile bond strength (TBS) was tested at a crosshead speed of 2 mm/min in a universal testing machine. Statistical analysis was conducted with Kruskal-Wallis-Test followed by Wilcoxon rank sum test adjusted by Bonferroni-Holm. Results: Mean TBS ± standard deviation of test groups in MPa after 3 days were: Pre-NO 0.5±0.8, Pre-ECU 3.2±2.3, Pre-LGB 14.5±2.6, Pre-CCP 0.0±0.0, Plu-SIL 3.9±1.9, Plu-CCP 1.6±1.5. After 150 days TBS were: Pre-NO 0.0±0.0, Pre-ECU 1.3±2.0, Pre-LGB 13.1±2.4, Pre-CCP 0.0±0.0, Plu-SIL 3.1±0.7, Plu-CCP 1.1±1.6. Group Pre-LGB showed significantly higher and more durable TBS than the other groups. Conclusion: The use of the methylmethacrylate containing primer Luxatemp Glaze&Bond after air-abrasion of PEEK surfaces can be recommended as promising bonding method to PEEK.