Aim: This study aimed to assess the effect of addition of nano-titanium oxide (nano-TiO2), nano-silicon dioxide (nano-SiO2), and a combination of both, on antimicrobial activity of an orthodontic composite.
Materials and methods: Molds measuring 0.64 × 0.5 mm were used for the fabrication of composite disks. For this purpose, 0.5% and 1% nano-TiO2, nano-SiO2, and a combination of both (0.5% nano-TiO2 and 0.5% nano-SiO2), were mixed with Transbond XT composite (3M Unitek). A total of 180 composite disks were fabricated for eluted component, disk agar diffusion (DAD), and biofilm inhibition tests. The colony counts of Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis), and Lactobacillus acidophilus (L. acidophilus) and the diameters of growth inhibition zones were measured at 3, 15, and 30 days after exposure to the materials. Data were analyzed using one-way ANOVA and a post hoc test.
Results: None of the nano-TiO2 and nano-SiO2 concentrations had any significant effect on the growth inhibition zone. All tested concentrations of nano-TiO2 and nano-SiO2 decreased the colony count of all bacteria. The composite sample containing both nano-TiO2 and nano-SiO2 had the greatest efficacy for reduction of S. mutans and S. sanguinis colony counts at all three time points. Also, 1% nano-TiO2 and 1% nano-SiO2 had similar effects on L. acidophilus in eluted component test.
Conclusion: Addition of TiO2 and SiO2 nanoparticles conferred antimicrobial property to the tested orthodontic composite.
Clinical significance: Using orthodontic composite containing nonoparticles with antibacterial activity may prevent dental caries.
Keywords: 2; Antimicrobial activity Nano-SiO; Nano-TiO; Orthodontic composite..