Comprehensive evaluation of early shear bond strength and antimicrobial activity in orthodontic adhesives enhanced with salvadora persica oil

Objectives: This study investigates the mechanical properties and antimicrobial efficiency of orthodontic adhesive modified with Salvadora persica (SP) oil, including adhesive remnant index (ARI) and shear bond strength (SBS), specifically antimicrobial efficacy against Streptococcus mutans.

Methods: Forty freshly extracted human premolars were recruited. They were classified into four groups according to the concentration of SP oil added to Heliosit orthodontic adhesive where the control group was with no adhesive modification, alongside three experimental groups, wherein SP oil was integrated into the adhesive at concentrations of 1%, 3%, and 5% weight/weight, respectively. The tooth buccal surface was etched by phosphoric acid gel (37%). The orthodontic brackets utilized were standard stainless steel edgewise 22". The brackets were bonded with Heliosit by Woodpecker LED light cure for 20 sec. The SBS was assessed using a universal testing machine, and ARI was inspected by a stereomicroscope at 20X magnification power. The antimicrobial activity against Streptococcus mutans was evaluated. The statistical analyses, analysis of variance (ANOVA), and Kruskal-Wallis and Duncan were performed where P ≤ 0.05.

Results: The findings indicated that among the experimental groups, the 3% SP oil group exhibited the highest mean SBS value, following closely behind the control group. Conversely, the mean SBS was lowest for the SP group with a 5% concentration. However, ANOVA and Kruskal-Wallis tests revealed no significant differences between groups (P ≥ 0.275, 0.069), respectively. Antimicrobial tests demonstrated a concentration-dependent antibacterial effect, the 5% group exhibiting the highest efficacy.

Conclusion: Orthodontic adhesive modified with SP oil maintains favorable SBS while demonstrating antimicrobial effects against Streptococcus mutans.