Evaluation of antibacterial effect of the orthodontic composite containing propolis nanoparticles in rat as an animal model

The present study aimed to assess the antimicrobial effects of orthodontic primer containing nano-propolis against the cariogenic bacteria in а rat model. Transbond XT orthodontic primer containing 0%, 1%, 5%, and 10% nano-propolis was experimentally prepared in-house. The Wistar rats we used in the study were randomly divided into four groups and their oral cavities were colonized with Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus. After anesthetizing the rats, one drop (10 µL) of primer containing different concentrations of nano-propolis was applied to the labial surface of the maxillary incisor and light-cured. The orthodontic composite was applied on the primer and light-cured. One drop (10 µL) of primer containing the same concentrations of nano-propolis was again applied on the surface of composite and light-cured. The number of S. mutans, S. sanguinis, and L. acidophilus colonies in the saliva of rats was quantified at 24 h, at days 4 and 7 using plate counting. Primer containing 1%, 5%, and 10% of nano-propolis significantly reduced the S. mutans colony count at 24 h compared with the control group (p