Influence of methylthioninium chloride, curcumin and Er, Cr: YSGG on caries affected dentin bonded to bioactive and conventional bulk fill dental restorative material

Aim: The study aimed to determine the influence of Er, Cr: YSGG (ECL), methylene blue photosensitizer (MBP), and curcumin photosensitizer (CP) disinfection on CAD and its bond strength and microleakage to bioactive (BA) and multicore (MC) bulk-fill composite. Materials and methods: Sixty carious mandibular molars were collected based on the criteria of ICDAS Code 6 (International Caries Detection and Assessment system). Specimens were embedded in polyvinyl pipes up to CEJ and subjected to preparation of standard class II cavity leaving CAD in situ for bonding. All samples were randomly assigned to eight groups based on disinfection regimes and type of bulk-fill material. Samples in group 5 and 6 didn't undergo any disinfection; group 1: ECL + BA, group 2: ECL+ MC; group 3 MBP + BA, group 4: MBP + MC; group 5: Conventional Etch and Rinse + BA (Control), group 6 Conventional Etch and Rinse + MC (Control); group 7: CP +BA and group 8 CP+MC. Specimens were tested for SBS using a universal testing machine and the debonded surfaces were evaluated under a stereomicroscope to determine modes of failure. A dye penetration test was performed for microleakage assessment. For intergroup comparison test analysis of variance (ANOVA) was performed using means and standard deviation from each group. Tukey HSD was used for multiple group comparison tests. The level of significance was established at p < 0.05. Results: The maximum mean bond strength was shown by group 6 (18.96 +/- 0.31 MPa) conventional etch and rinse+ MC (control). Whereas, the minimum SBS was recorded in specimens of group 7 CP +BA (13.04 +/- 0.81 MPa). SBS values among group 3 (14.05 +/- 0.10 MPa- MBP+BA), group 4 (13.66 +/- 0.39- MBP+MC) group 7 (13.04 +/- 0.81 MPa- CP +BA and group 8 (14.21 +/- 0.59 MPa- CP+MC) were found to be comparable (p>0.05). There was no statistically significant difference among the study groups concerning microleakage (p >0.05). Conclusion: CAD treated with ECL for the adhesive bonding of BA and conventional bulk-fill composite MC has shown potential to be used clinically. Moreover, MBP and CP for conditioning of CAD need further investigation.