The effect of different air blasting pressure of polyetheretherketone (PEEK) on surface roughness and bond strength to adhesive resin cement: An in-vitro study

Statement of the Problem: Polyetheretherketone material shows good physical and mechanical properties but research is lacking optimum air blasting parameters for good bond strength to resin cement. Aim: To evaluate the effect of different air blasting pressure of PEEK on surface roughness and shear bond strength to adhesive resin cement. Materials and Methods: 24 discs of BioHPP PEEK (bredent, UK) were manufactured. Samples were air blasted with 110 μm Al 2 O 3 particles for 10 seconds at distance of 10 mm and divided into 3 groups according to pressure. Group A: 3 bar, Group B: 2.5 bar and Group C: 3.5 bar. Surface roughness was measured by SEM, Visio Link primer (Bredent, Germany) was applied and cured then G-CEM resin cement (GC, Japan) was applied and cured. Shear bond strength was measured using universal testing machine. EDX analysis was done, and failure mode was detected by stereo-microscope. Results: Statistical analysis showed that roughness average (Ra) increased by increasing pressure, Group B was significantly the lowest ( p < 0.05), while there was insignificant difference between other groups (P > 0.05). Regarding shear bond strength, Group A recorded (12.6864 ± 2.486 MPa), Group B (11.2842 ± 1.555 MPa) and Group C (10.1024 ± 2.317 MPa), there was significantly statistical difference between Groups A & C ( p < 0.05). The failure mode was mainly adhesive in group C and mixed in groups A & B. EDX analysis showed an increase in Carbon and Silica and a decrease in Oxygen and Aluminum weight percentages after the bond strength test. Conclusion: Increasing the air blasting pressure up to 3 bar increases the surface roughness and bond strength to resin cement, but more than 3 bar showed unfavorable surface roughness and decreased bond strength.