Influence of Er: Cr: YSGG laser on adhesive strength and microleakage of dentin bonded to resin composite. In-vitro study

Background: The aim of this study was to evaluate the surface treatment of dentin with phototherapy (ER-CR-YSGG laser) in the presence of different bonding systems on their shear bond strength and microleakage. Materials and methods: Eighty intact human third molars were divided into two groups. Forty teeth were treated with conventional flat wheel diamond bur and the remaining forty were treated with Er Cr YSGG laser (phototherapy). The two groups i.e. treated with laser (l) and group treated with abrasive bur (NL) were further divided into two subgroups of twenty samples each. Subgroup 1 was surface treated with etch and rinse (ER) and other 20 remaining samples were treated with self- etch (SE) bonding regime. Specimens from all the groups were assessed for shear bond strength and microleakage scores. Ten samples from all groups were immersed in 2% methylene blue for 24 h and assessed under a digital microscope for microleakage. Data was assessed using analysis of variance and tukey multiple comparisons test. Results: The lowest bond strength was achieved in laser prepared phototherapy group bonded with self-etch (LSE-11.87 ± 1.21). The maximum bond strength score was observed in non-laser-etch and rinse group (NLER-23.66 ± 2.56). The highest mean microleakage was observed among laser bonded with self-etch (LSE) specimens (1.0 ± 0.13). The lowest microleakage scores were seen in group treated with non-phototherapy etch and rinse (NLER-0.4 ± 0.11) regime. Conclusion: Use of etch and rinse dentin bonding regime in combination with ER-CR-YSGG phototherapy dentin treatment has the potential for clinical application in comparison to conventional conditioning technique.