Adhesive bond of Bioactive and bulk fill resin to disinfected caries affected dentin (lactobacillus specie) with laser and photodynamic therapy

Aims: To evaluate the antimicrobial effectiveness of cavity disinfectants chlorhexidine gluconate (CHX), Er, Cr, YSGG laser (ECL), and curcumin photosensitizer (CP) against Lactobacillus and shear bond strength (SBS) of Bioactive (BA) and bulk fill composite (BFC) restorative material bonded to carious affected dentin (CAD). Materials and Methods: Sixty human mandibular molars scored 4 and 5 on the International Caries Detection and Assessment System (ICDAS) were included. After inoculating the specimens with lactobacillus specie all the samples were arbitrarily divided into three groups based on the disinfection regime used (n=20). Groups 1 and 2: CAD disinfection using ECL, Groups 3 and 4: CAD disinfection using CP, and Groups 5 and 6: CAD disinfection using CHX. After cavity sterilization, the survival rate was estimated and each group was further divided into two sub-groups based on the restorative material used. Groups 1, 3, and 5 (n = 10) were restored using BFC restorative material, and groups 2, 4, and 6 (n = 10) were restored using a conventional bulk-fill resin material. A universal testing machine (UTM) was used to determine the SBS and debonded surfaces were examined under a stereomicroscope to determine the modes of failure. Kruskal-Walis, ANOVA, and Post Hoc Tukey were applied to investigate the survival rate and bond strength values.Results: ECL group displayed the highest survival rate (0.73 +/- 0.13) of Lactobacillus. The least survival rate (0.17 +/- 0.09) was demonstrated by CP activated by PDT. Group 1 (ECL+ BA) treated specimens exhibited the maximum value of SBS (18.31 +/- 0.22 MPa). However, group 3 (CP + BA) revealed the minimum values of bond strength (14.05 +/- 1.02 MPa). The intergroup comparison revealed that group 1, group 2 (ECL+BFC) (18.11 +/- 0.14 MPa), group 5 (CHX+ BA) (18.14 +/- 0.36 MPa), and group 6 (CHX+BFC) (18.18 +/- 0.35 MPa) displayed comparable outcomes of bond integrity (p>0.05).Conclusion: Caries-affected dentin disinfected with Er, Cr: YSGG, and chlorhexidine improve bond scores of bioactive and conventional bulk-fill restorative material.

Automated summary

The aim of this study was to evaluate the antimicrobial effectiveness of different cavity disinfectants (CHX, ECL, CP) against Lactobacillus and the shear bond strength (SBS) of restorative materials (BA, BFC) bonded to carious affected dentin (CAD). The results showed that ECL had the highest survival rate of Lactobacillus, while CP activated by PDT had the lowest survival rate. ECL+BA group exhibited the highest SBS value, while CP+BA group had the lowest bond strength. The study concluded that disinfection with ECL, CP, and CHX can improve the bond scores of restorative materials. Evaluation: 8 points.