Background: Dental implant therapy is currently identified as the most effective treatment for edentulous patient. However, peri-implant inflammations were found to be one of the most common complications that leads to the loss and failure of dental implantation. Ultraviolet (UV) radiation has been proposed to enhance bone integration and reduce bacterial attachment. In this study, we aimed to systematically review the current evidence regarding the antimicrobial effect of UV on different dental implant surfaces. Methods: Five databases including PubMed, Scopus, Web of science, VHL, and Cochran Library were searched to retrieve relevant articles. All original reports that examined the effect of the application of UV radiation on dental implants were included in our study. Results: A total of 16 in vitro studies were included in this systematic review. Polymethyl methacrylate UV radiation has induced a significant decrease in bacterial survival in PMMA materials, with an increased effect by modification with 2.5% and 5% TiO₂ nanotubes. UV-C showed a superior effect to UV-A in reducing bacterial attachment and accumulation. UV wavelength of 265 and 285 nm showed powerful bactericidal effects. UV of 365 nm for 24 h had the highest inhibition of bacterial growth in ZnO coated magnesium alloys. In UV-irradiated commercially pure titanium surfaces treated with plasma electrolytic oxidation, silver ion application, heat or alkali had shown significant higher bactericidal effect vs non-irradiated treated surfaces than the treatment with any of them alone. UVC and gamma-ray irradiation increased the hydrophilicity of zirconia surface, compared to the dry heat. Conclusion: UV radiation on Ti surfaces exhibited significant antibacterial effects demonstrated through the reduction in bacterial attachment and biofilm formation with suppression of bacterial cells growth. Combination of UV and treated surfaces with alkali, plasma electrolytic oxidation, silver ion application or heat enhance the overall photocatalytic antimicrobial effect.

Background: Microorganisms along with host response play a key role in the development of periodontal and peri-implant infections. Advanced periodontal and peri-implant diseases are most likely associated with bacterial plaques that trigger host immune response and eventually lead to the destruction of the attachment apparatus and bone loss around a tooth or a dental implant. A recent systematic review and meta-analysis revealed that Aggregatibacter actinomycetemcomitans had the highest association with peri-implantitis. Resolvin E1 (RvE1) is part of the specialized pro-resolving lipid mediator family biosynthesized from omega-3, polyunsaturated fatty acids (PUFAs), and eicosapentaenoic acid (EPA). Although RvE1 is an established anti-inflammatory agent, it was found that its application as a treatment or as a preventive drug had an indirect effect on the subgingival microbiota of both rats and rabbits with experimental periodontitis.Aim: The aim of this study is to evaluate the direct antimicrobial effect of RvE1 on Aggregatibacter actinomycetemcomitans bacteria.Materials and Methods: The study comprised three groups that underwent minimum inhibitory concentration (MIC) against Aggregatibacter actinomycetemcomitans. The first group was tested with the RvE1 working concentration of 5 ug/ml, the second group was tested with ethanol (EtOH), 10% as the working concentration, and the final group was diluted in phosphate-buffered saline (PBS) as the positive control. Optical density (OD₆₀₀) was used for the comparison of bacterial growth among the tested groups. The experiment was conducted in three biological replicates. Data were analyzed using SPSS, and results were analyzed by using one-way analysis of variance (ANOVA) followed by post-hoc Bonferroni using a minimum level of significance (P-value) of 0.05.Results: Minimum inhibitory concentration was 1.25 μg/ml and 5% for RvE1 and EtOH, respectively. RvE1's mean optical density (OD₆₀₀) was 0.156 ± 0.021 and was significantly lower compared with all the other groups (P-value < 0.01). The EtOH group (mean OD₆₀₀ 0.178 ± 0.013) and the PBS group (mean OD₆₀₀ 0.1855 ± 0.022) did not reveal a significant difference (P-value = 0.185).Conclusion: RvE1 demonstrated significant antimicrobial activity against A. actinomycetemcomitans with an MIC of 1.25 μg/ml. The RvE1 group showed significantly lower bacterial growth compared to the EtOH and PBS groups.