LAUSR

INTRODUCTION Titanium-based implants are widely used due to their good biocompatibility and high corrosion resistance. Infections after implant placement are the main reason for the failure of implant treatment. Some recent studies have also shown that microbial contamination can occur at the implant-abutment level in implants with the healthy or diseased surrounding tissue. The purpose of this study is to investigate the antibacterial effect of slow-release nanoparticles of polylactic co-glycolic acid (PLGA) loaded with chlorhexidine (CHX) inside the implant fixture. MATERIALS AND METHODS The number of thirty-six implants in three groups were examined in the bacterial culture environment. In the first group, PLGA/CHX nanoparticles, in the second group, the negative control group (distilled water) and in the third group, the positive control group (chlorhexidine) were used. The bacterial suspensions including Escherichia coli ATCC: 25922, Staphylococcus aureus ATCC: 6538 and Enterococcus faecalis ATCC: 29212 were used to investigate the antimicrobial effect of the prepared nanoparticles. RESULTS The results showed that the use of PLGA/CHX nanoparticles significantly inhibited the growth of all three bacteria. Nanoparticles loaded with chlorhexidine had a significant decrease in the growth rate of all three bacteria compared to chlorhexidine and water. The lowest bacterial growth rate was observed in the Enterococcus faecalis/PLGA nanoparticles group, and the highest bacterial growth rate was observed in the Staphylococcus aureus/H2O group. CONCLUSION The current study showed that the use of PLGA/CHX nanoparticles can significantly inhibit the growth of all three bacteria. Of course, the current study was conducted in vitro and to obtain clinical results, we need to conduct a study on human samples. In addition, the results of this study showed that the chemical antimicrobial materials can be used in low concentrations and in a sustained-released manner in cases of dealing with bacterial infections, which can lead to better and targeted performance as well as reducing possible side effects.