Influence of photobio-modulation with an Er,Cr: YSGG laser on dentin adhesion bonded with bioactive and resin-modified glass ionomer cement

The aim of the present study was to evaluate the shear bond strength (SBS) of bioactive cement (BAC) in comparison to conventional dual cure resin-modified glass ionomer cement (RMGIC) with Er,Cr:YSGG laser (ECL) dentin photo biomodulation. Methods: One hundred and twenty extracted human molars were allocated in eight groups (n = 15) based on surface conditioning and cement type. Specimens of groups 2 and 6 were conditioned with ECL whereas, groups 3 and 7 were treated with ECL + ethylenediamine tetra acetic acid (EDTA). Specimens in groups 4 and 8 were surface conditioned by ECL + EDTA + Tetric-N-Bond, and groups 1 and 5 were considered as control (non-surface treated). Cement build-ups were performed on the surface-treated dentin with BAC (groups 1-4) and RMGIC (groups 5-8). A universal testing machine was used to measure the SBS and the mode of failure was evaluated using a stereomicroscope. Statistical analysis was performed using an analysis of variance and Tukey's post hoc test, at a significance level of p < 0.001. Results: The highest SBS values were observed in group 8, ECL + EDTA + Tetric-N-Bond + RMGIC (21.54 +/- 3.524 MPa) and the lowest SBS values were displayed by group 1, with no surface treatment and BAC application (11.99 +/- 0.821 MPa). The majority of failures were found to be mixed in lased dentin-treated dentin surfaces. BAC when bonded to dentin surfaces conditioned with ECL showed lower SBS in comparison to RMGIC. Conclusion: Conditioning of dentin with ECL and a bonding agent (Tetric-N-bond) improved bond strength scores for BAC and RMGIC. Use of EDTA improved bond strength values when bonded to BAC and RMGIC; however, this improvement was not statistically significant.