Comparison of anti-microbial effects of Stevia Rebaudiana extract and Xylitol on dental biofilm - an in vitro study

Objectives: This in-vitro study aimed to assess the antibacterial effects of xylitol and Stevia rebaudiana ethanolic extract on oral biofilm.
Methods: Microbial biofilm was created on acrylic discs via inoculation with Streptococcus mutans and Streptococcus sobrinus. The discs were immersed in solutions of 1 and 3% xylitol and 2 and 4 mg/mL ethanolic extract of Stevia. After 16 hours of incubation, discs were rinsed with saline and transferred to Fluid Universal Medium (FUM). The above-mentioned solutions were spirally cultured on specific culture media for each bacterium. Culture media for S. mutans and S. sobrinus were incubated for 24 hours. Number of colony forming units (CFUs) in each medium was counted. Structure of biofilm in each group was evaluated under a scanning electron microscope (SEM).
Results: Stevia significantly inhibited S. mutans biofilm compared to the control group. Xylitol had no such effect on S. mutans biofilm. Both xylitol and Stevia significantly inhibited S. sobrinus biofilm.
Conclusions: Stevia extract seems to be more potent against dental biofilms compared to Xylitol.