Antibacterial efficacy of oxygen rich fluid against three early colonizing peri-implant bacteria.

The management of peri-implantitis is a relatively new area of research and clinical practice. As of yet, no specific treatment protocol has been proven to be absolutely successful or considered as the gold standard. Oxygenated agents have demonstrated potential benefits when they come to treating periodontal disease, however, studies regarding their use in the treatment of peri-implantitis are lacking. The purpose of this study is to evaluate the direct antimicrobial efficacy of Oxygen-rich fluid against three early peri-implant colonizing bacteria, namely, Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). The study was designed to evaluate the minimum inhibitory concentration (MIC) of Oxygen-rich fluid BlueM against E. coli, S. aureus, and P. aeruginosa using micro-serial dilution method. BlueM was tested as the experimental group, while 0.2% Chlorhexidine (CHX) as the positive control, and sterile Mueller-Hinton broth (MHB) as the negative control. Each bacterial suspension was prepared at an optical density (OD600 of 0.1) and inoculated into separate rows of a 96-well plate. The plates were incubated at 35 °C for 48 h using the Bioscreen C assay reader, with optical density measurements recorded hourly. For the time-kill assay, the Oxygen-rich agent was tested at its MIC, 2xMIC, and 4xMIC levels. Added to the wells were 180 µL of MHB, 150 µL of the Oxygen-rich agent, and 10 µL of bacterial suspension. Growth was measured at 1, 2, 5, and 30 min. Serial dilutions were performed, and the plates were further incubated at 37 °C for 18-24 h, and colonies were counted. All tests were performed in triplicates. The data were evaluated by using ANOVA test followed by post hoc Tukey test. The within-group comparison at four-time intervals was compared using Repeated measure ANOVA test. The MIC of the Oxygen-rich fluid was assessed against E. coli, S. aureus, and P. aeruginosa. E. coli exhibited the highest susceptibility, with an MIC of 1.25 mg/L, followed by S. aureus at 2.5 mg/L, and P. aeruginosa at 5 mg/L. The time-kill assay showed a time-dependent reduction in bacterial counts, with significant decreases observed for all strains over the 30-minute testing period. However, despite testing multiple concentrations (MICx1, MICx2, MICx4), no significant differences in bacterial inhibition were observed across these concentrations, indicating that the fluid's antimicrobial effect is consistent across concentrations. The Oxygen-rich fluid demonstrated effective antimicrobial activity against E. coli, S. aureus, and P. aeruginosa, with no significant difference observed across concentrations. The fluid's time-dependent antibacterial effects suggest its potential for use in clinical settings and personal oral care, particularly for managing bacterial infections in peri-implant disease.