Outcome of Er, Cr:YSGG laser and antioxidant pretreatments on bonding quality to caries-induced dentin.

Background: This study aimed to assess the influence of different pretreatment protocols and antioxidants application on the shear bond strength (SBS) of universal adhesive to sound (SoD) and caries-induced dentin (CID).

Methods: One hundred and twenty posterior teeth had their occlusal enamel removed, then the specimens were divided into two main groups according to dentin substrates; SoD and CID, three subgroups according to pretreatments protocols control (no pretreatment), NaOCl-treated, and Er, Cr:YSGG-treated and two divisions according to antioxidant application (with and without sodium ascorbate (SA) application). All-Bond Universal (ABU) universal adhesives was applied in self-etch (SE) mode then resin composite discs were built. The specimens were stored in distilled water for 24-hr at 37°C before SBS testing. Three-way ANOVA and Tukey HSD tests were used for data analysis (a = 0.05).

Results: 6% NaOCl resulted in a significant reduction in SBS in SoD without antioxidant application. 10% SA application showed significant increase in SBS for 6% NaOCl group only in SoD. Laser application recorded a significantly higher SBS compared to 6% NaOCl group without or with antioxidant application, while 10% SA application revealed a significant increase in SBS for control group only.

Conclusions: Er, Cr:YSGG laser irradiation followed by antioxidant application has the potential to enhance the bonding quality of both tested dentin substrates. NaOCl application has significantly compromised the bonding to SoD and CID substrates.