Influence of surface treatment on repair bond strength of CAD/CAM long-term provisional restorative materials: an in vitro study

BackgroundThe surface treatment to improve the repair bond strength may vary because CAD/CAM provisional restoration polymers exhibit a variety of microstructures. This study was conducted to evaluate the effect of surface treatments on the repairability of three different CAD/CAM polymers for long-term provisional restorations.MethodsThirty specimens from each provisional restorative materials (CAD-Temp, Everest C-Temp, and PEEK) were divided into three groups: C: surfaces received no treatment; SB: surfaces were airborne particle abraded with 50 mu m aluminum oxide; SB-T: surfaces received the same conditions as group SB in addition to thermocycling before and after treatment. Primer and nanohybrid repair resin composite were applied to the prepared CAD /CAM surfaces. The shear bond strength and the mode of failure were assessed. ANOVA and Tukey's significant difference tests were used to evaluate the data.ResultsThe SB group had significantly higher repair SBS values (p < .001) compared to the other groups (C and SB-T). Everest C-Temp significantly recorded the highest repair SBS (17.84 +/- 0.19 MPa) in group SB, while the lowest repair SBS values (5.51 +/- 1.14 MPa) for CAD-Temp were recorded in group C. PEEK significantly recorded the second highest repair SBS (15.96 +/- 0.18) in the SB group.ConclusionsEverest C-Temp had the highest repair SBS after an airborne abrasion particle. Thermocycling had no significant effect on the repair SBS for PEEK. Everest C-Temp and PEEK are recommended as long-term durable provisional materials for clinical use.