Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.

Implants have been considered the treatment of choice to replace missing teeth, unfortunately, peri-implant disease is still an unresolved issue. Contaminated implants may be decontaminated by physical debridement and chemical disinfectants; however, there is a lack of consensus regarding the ideal techniques/agents to be used for the decontamination. The objective of our study was to compare the decontaminating efficacy of different chemical agents on a titanium surface contaminated with Porphyromonas gingivalis, a typical representative of the bacterial flora associated with peri-implantitis. Commercially pure Ti grade 4 discs with a polished surface were treated with a mouthwash containing chlorhexidine digluconate (0.1%), povidone-iodine (PVP-iodine) solution (10%) or citric acid monohydrate (40%). Qualitative and quantitative assessment of cellular growth and survival were assessed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and scanning electron microscopy (SEM). Significant differences in the quantity of P. gingivalis could be observed after 6 days of incubation. A numerical, but not statistically significant (P = 0.066) decrease in the amount of living bacteria was observed in the group treated with the PVP-iodine solution as compared to the control group. The chlorhexidine (CHX)-treated group presented with significantly higher cell counts, as compared to the PVP-iodine-treated group (P = 0.032), while this was not observed compared to the control group and citric acid-treated group. Our results have also been verified by SEM measurements. Our results suggest that for P. gingivalis contamination on a titanium surface in vitro, PVP-iodine is a superior decontaminant, compared to citric acid and chlorhexidine-digulconate solution.

The biofilm formation by oral bacteria on the implant surface is one of the most remarkable factors of peri-implant infections, which may eventually lead to bone resorption and loss of the dental implant. Therefore, the elimination of biofilm is an essential step for the successful therapy of implant-related infections. In this work we created a basic in vitro model to evaluate the antibacterial effect of three widely used antiseptics. Commercially pure (CP4) titanium sample discs with sand blasted, acid etched, and polished surface were used. The discs were incubated with mono-cultures of Streptococcus mitis and Streptococcus salivarius. The adhered bacterial biofilms were treated with different antiseptics: chlorhexidine-digluconate (CHX), povidone-iodine (PI), and chlorine dioxide (CD) for 5 min and the control discs with ultrapure water. The antibacterial effect of the antiseptics was tested by colorimetric assay. According to the results, the PI and the CD were statistically the most effective in the elimination of the two test bacteria on both titanium surfaces after 5 min treatment time. The CD showed significant effect only against S. salivarius. Based on our results we conclude that PI and CD may be promising antibacterial agents to disinfecting the peri-implant site in the dental practice.

No abstract

No abstract