Influence of photodynamic therapy and different lasers Er,Cr:YSGG and Er, YAG on dentin conditioning bonded to conventional and bioactive cement

Aim: The aim of the present study was to evaluate the bond integrity of bioactive cement (BA(c)) in contrast to conventional cement Calibra (C) after dentin treated with different surface conditioners (PDT, EYL, ECL) Materials and Methods: Sixty non-carious permanent mandibular molars were disinfected and embedded in acrylic resin till cement-o-enamel junction. For homogeneity the buccal surface were grounded and polished. Samples were categorized into three main groups based on conditioning technique. Samples in group 1 and 2 dentin conditioned with Er,Cr:YSGG (ECL), group 3 and 4 surface treated with Er:YAG (EYL) and group 5 and 6 treated with photodynamic therapy (PDT).On conditioned surface bonding agent was applied and light cured. Samples from group 1,3,5 were bonded to Calibra (C). Whereas, specimens in group 2,4,6 were conditioned with bioactive cement (BA(c)) and subjected to ageing followed by shear bond strength testing (SBS) in universal testing machine. To detect significance difference between means of different groups analysis of variance (ANOVA) was performed followed by Tukey's post-hoc tests. Results: The maximum SBS was displayed in group 1, dentin conditioned with ECL and bonded to C (20.23 +/- 0.47 MPa). Whereas, group 6, PDT of dentin to BA(c) demonstrated lowest bond integrity among experimental groups (12.97 +/- 0.25 MPa). Bond strength of group 1, ECL-C (21.55 +/- 3.08 MPa) and group 3 EYL-C (19.11 +/- 0.65 MPa) were comparable (p > 0.05). Group 5 samples treated with PDT, MB-C (13.41 +/- 0.32 MPa) and group 6, MB-BA(c) (12.97 +/- 0.25 MPa) were also comparable (p > 0.05) Conclusion: BA(c) bonded to dentin after surface conditioning with ECL, EYL and PDT presented lower SBS in comparison to conventional cement C. Further studies are required to extrapolate the current findings.