Antibacterial effect of bioactive glass incorporated in acrylic resins against Streptococcus mutans and Lactobacillus acidophilus activity in biofilm

Abstract

Objective: The rough surfaces of removable appliances used in pediatric dentistry or orthodontics, may result in
an environment for biofilm accumulation, yielding to enamel demineralization. This study aimed to assess the
effects of adding nanoparticles of bioactive glass to polymethylmethacrylate to promote the antibacterial activity
in acrylic resins. Material and Methods: Acrylic resin specimens (20x20x1mm3) were prepared by adding 2% or
5% bioactive glass. The specimens in the control group without bioactive glass were prepared from the mixture
of acrylic powder containing nanoparticles and liquid monomer (n=10 per group). The antibacterial activity of
the specimens against Streptococcus mutans and Lactobacillus acidophilus activity in biofilm was investigated
through counting colony forming units (CFU). Data were analyzed using a one-way analysis of variance and
Tukey’s post hoc tests at the significance level of 0.05. Results: The incorporation of 2% (p=0.001) and 5%
(p<0.001) bioactive glass in acrylic resin reduced the metabolic activity and CFU of L. acidophilus. For S.mutans,
antimicrobial activity was observed only with the 5% concentration of bioactive glass, and this group was
statistically different from the control (p<0.001). When L. acidophilus was exposed to polymethyl methacrylate
with 5% bioactive glass, significant decrease was observed compared to the control group (p<0.05). Conclusion:
Adding bioactive glass nanoparticles into the acrylic resins used for fabricating removable appliances revealed
a greater antibacterial effect against cariogenic bacteria tested.

KEYWORDS
Acrylic resins; Anti-bacterial agents; Bioactive glass; Dental materials; Pediatric dentistry.