Effect of Different Surface Treatment Methods on Micro-Shear Bond Strength of CAD-CAM Restorative Materials to Resin Cement.

This study aimed to investigate the micro-shear bond strength (SBS) of surface treated CAD-CAM materials to resin cement. The specimens obtained from IPS e.max CAD, Lava Ultimate, Cerasmart and Vita Enamic were divided according to the surface treatment method applied as: no treatment, 3W and 2W Er, Cr:YSGG laser irradiation, sandblasting and 5% hydrofluoric acid (HF) application. Then, SBS and field emission-scanning electron microscope analysis were performed. Data were analyzed using the Mann Whitney U and the Kruskal Wallis tests. For all materials, the highest SBS values were demonstrated in HF acid applied groups. Regarding the SBS values of IPS e.max CAD, no significant differences were found among control, 2W Er, Cr:YSGG laser and sandblasting groups (p>0.05). For Cerasmart and Lava Ultimate; 2W Er, Cr:YSGG laser treated group showed significantly lowest SBS values while there was no significant difference among control, 3W Er, Cr:YSGG and sandblasting groups. HF applied Lava Ultimate and IPS e.max CAD groups exhibited the highest SBS values among all the groups. For Vita Enamic; significantly lowest SBS values were obtained in sandblasting group, whereas there was no significant difference among control, 3W Er, Cr:YSGG and 2W Er, Cr:YSGG groups (p>0.05). The FE-SEM images of all CAD-CAM materials submitted to surface treatment revealed an increase in surface alterations compared to control groups. It can be concluded that prior to bonding 5% HF acid treatment is the best surface treatment method regarding the bond strength for all CAD-CAM restorative materials. Er, Cr:YSGG laser application with energy level of 3W can be recommended for IPS e.max CAD.