Introduction This study investigates the adhesion of Streptococcus mutans to fixed orthodontic wires in varying types of saliva under laboratory conditions, given the heightened microbial load and increased caries prevalence in patients with orthodontic appliances. Materials and Methods Stainless steel and nickel-titanium arch-wires of the same dimensions were utilized. In this study, a total of 24 samples in six sub group of were used. After preparation and sterilization, the samples were immersed in artificial saliva solutions for two hours with either normal or acidic pH. Subsequently, the samples were incubated in an S. mutans suspension. Following serial dilution and cultivation on brain heart infusion (BHI) agar, the number of former colonies was counted. The data were analyzed using two-way ANOVA with a significance level of p ≤ 0.05. Results The adhesion rate of S. mutans to the stainless steel arch-wires was significantly higher than the nickel-titanium arch-wires in both acidic and normal saliva ( p ≤ 0.05). Moreover, the adhesion rate of both arch-wires was lower in acidic saliva compared to normal saliva ( p ≤ 0.05). Discussion According to the results of this research, the adhesion rates of S. mutans were different for arch-wire materials. This research provided insights that could guide the selection of materials used in orthodontics. Conclusion S. mutans exhibits a lower adhesion rate of the nickel-titanium arch-wires compared to the stainless steel arch-wires in both acidic and normal saliva.
Mirmohammadi et al. (Wed,) studied this question.