The impact of different cleaning protocols on resin bond strength to polymer-infiltrated ceramic material

Purpose: This study measured and compared shear bond strength (SBS) of a composite resin cement with that of PICN material after different surface cleaning methods. Materials and Methods: Forty Vita-Enamic plates (10x7x2 mm) were fabricated using of a low speed, water-cooled diamond saw. All plates were air-borne particle abraded using 50µm Al2O3 then contaminated with saliva, after that all plates were classified into four groups (n=10): control group (CG) in which conventional cleaning with air-water spry was used, and three test groups as follow: ultrasonic cleaning (UCG), steam cleaning (SCG), Ivoclean cleaning (ICG). Composite resin discs (Nexcomp) were cemented to ceramic plates using self-adhesive resin cement (Charm Supercem). All bonded specimens were stored in 37°C water for 1 month then, thermocycled 1000 times in water baths between 5˚C and 55˚C. Shear bond strength (SBS) test was performed using a universal testing machine. Scanning Electron Microscope (SEM) was used for failure mode examination. Results: Different cleaning methods significantly increased SBS values of tested groups compared to control one (p=0.000). The highest mean SBS (MPa) was reported for (SC) test group (18.41±1.5 MPa) followed by (UC) test group (11.52±.99MPa). While the lowest mean SBS was observed for (CG) (4.00 ±.59 MPa). There was statistically significant difference between (SCG) and other groups (CG, UCG, ICG) (p=0.0001). There was no statistically significant difference between IC and UC test groups (p=0.2941). Conclusion: Within the limitation of the present study, the bond strength of self-adhesive resin cement to hybrid ceramics increased by different surface cleaning protocols.