Shear bond characteristics and surface roughness of poly-ether-ether-ketone treated with contemporary surface treatment regimes bonded to composite resin

Aim: To evaluate and compare the influence of contemporary surface treatments of air abrasions, sulfuric acid, and Photodynamic therapy (PDT) on the adhesive bonding and surface roughness of Poly-ether-ether-ketone (PEEK) bonded to resin composite. Material and methods: One hundred and fifty PEEK (disk-shaped) specimens of 10 mm diameter and 2 mm thickness were prepared. Specimens were subjected to the following surface treatments, Control (no treatment), PDT, air abrasion using Alumina particles (110 μm) (AA-AP), Sulfuric acid (SA), and air abrasion using diamond particles (10–20 μm) AA-DP. Surface roughness (Ra) of treated samples were evaluated using surface profilometer. Universal testing machine was used to evaluate shear bond strength after composite resin build-up. Stereomicroscope was utilized for failure analysis of de-bonded samples of all five groups. Statistical analysis was performed utilizing one-way analysis of variance (ANOVA) to measure means and standard deviations of SBS among studied groups and the means of SBS were paralleled by Tukey multiple comparison tests (p > 0.05). Results: The highest SBS was observed by 98% SA (19.25 ± 0.68 MPa). While specimen treated with PDT (11.69 ± 0.12 MPa) showed the lowest SBS. PEEK surface, treated with PDT and AA-DP demonstrated comparable SBS (p > 0.05). PEEK when pretreated with 98% SA (2.658 ± 0.658 μm) exhibited a significantly higher Ra value as compared to other surface-treated groups (p < 0.05). Conclusion: PEEK surface treated with SA showed the highest SBS and surface roughness compared to other groups. Surface roughness of PEEK treated with PDT, AA-AP, and AA-DP demonstrated no difference in Ra. PEEK surface treatment technique should be further investigated to develop reliable adhesive resin bonding.