Aloe-Emodin activated by Photodynamic therapy and diode laser on carious affected dentin and survival of S. mutans. An-invitro SEM assessment

To evaluate the effect of different sterilizing agents i.e., Chlorhexidine (CHX), Diode laser (DL) and Aloe-emodin (AE) activated via Photodynamic therapy (PDT) on the viability of Streptococcus mutans (S. mutans) and the shear bond strength (SBS) of self-etch (SE) adhesive to carious affected dentin (CAD) MATERIAL AND METHODS: Forty-four human molars in which carious lesion extends up to the middle third of the dentin ICDAS criteria- 5 were collected and disinfected using 0.5% chloramine Tsolution. To identify the CAD, visual and tactile examinations were used. Specimens were randomly assigned into four experimental cohorts based on cavity disinfection protocol (n=11) Group 1 (No disinfection), Group 2 (CHX), Group 3 (DL), and Group 4 (AE-mediated PDT). Fresh cultures of S.mutans were cultivated on CAD and their survival rate assessment was performed following the type of disinfection. SE adhesive and composite application were performed on CAD following assessment of SBS and failure mode utilizing a universal testing machine (UTM) and stereo microscope respectively. Quantification of resin tags was performed via Scanning electron Microscopy (SEM). One-way ANOVA and Tukey post hoc test were implemented to investigate the statistical variances among different experimental groups (p≤0.05) RESULTS: The lowest survival rate was presented in Group 4 (AE mediated PDT) (1.52±1.32CFU/mL) samples. Whereas, the highest survival was established in control (3.27±0.82 CFU /mL). Group 3 (DL) treated CAD presented the lowest bond strength (7.12±0.03MPa) and shortest resin tag length (53.79±2.32μ m). Whereas, the highest SBS (9.45±0.14MP) and longest resin tags (109.21 ± 1.09μ m) were exhibited by Group 4 (AE-mediated PDT) CONCLUSION: Aloe-Emodin mediated photodynamic therapy could serve as a potent approach for CAD disinfection as it exhibits exceptional antibacterial efficiency and also enhances the bond strength of the self-etch adhesive to carious affected dentin.