The application of the Er,Cr:YSGG laser surface treatment to CAD/CAM resin ceramic blocks to improve their bonding to the resin luting agent

Objectives: The purpose of this study was to evaluate the effect of Er,Cr:YSGG laser surface treatment on the bonding of CAD/CAM resin ceramic blocks to a resin luting agent using various irradiation parameters. Methods: Eleven groups (n = 10) comprising CAD/CAM resin ceramic plates that underwent various surface treatment methods were used as follows: one control group (no treatment: C), one airborne particle abrasion group (AA), and nine Er,Cr:YSGG laser irradiation groups (L). These groups were exposed to various intensities (1.00, 1.25, and 1.50 W) and frequencies (15, 20, and 25 Hz) of the laser. The shear bond strength (SBS) between the CAD/CAM resin ceramic plate and resin luting agent with a failure mode analysis following the SBS test, surface roughness, and surface energy of the CAD/CAM resin ceramic plates was determined. The surface-treated specimens and the representative debonded surfaces of specimens were observed via scanning electron microscopy. Results: The surface treatments significantly influenced the SBS, surface energy, and surface roughness. Group L (1.25 W–20 Hz) exhibited a significantly higher SBS than group C, but not group AA. Furthermore, the specimens in the L groups (1.25 W–15 Hz, 1.25 W–20 Hz, 1.50 W–15 Hz, 1.50 W–20 Hz, and 1.00 W–15 Hz) presented significantly higher surface roughness than those in groups C and AA. No significant difference in surface energy was observed among the L1.00–15, L1.00–20, C, and AA groups. Conclusion: The surface treatment of the CAD/CAM resin ceramic using Er,Cr:YSGG laser irradiation (1.25 W and 20 Hz) proved useful in obtaining a high bond strength between the block and resin luting agent, similar to that observed using the airborne particle abrasion method. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.