The Application Of Photodynamic Antimicrobial Chemotherapy In Prevention Of Peri-implantitis And Its Mechanism

[Objective]Here we aimed to detect levels of pathogens from peri-implant sulcus as well as from abutment screw cavities after photodynamic therapy,and its impact on peri-implant sulcus inflammatory factors.In order to evaluate its effects on the prevention of peri-implantitis.[Materials and methods]1.Culture standard bacteria strain,establish standard curve of real-time PCR of each bacteria.2.Appply photodynamic therapy in peri-implant sulcus as well as in the cavity between abutment and implant,paper point was used for sampling.3.Quantitative real-time PCR was applied to detect the amount of P.gingivalis,F.nucleatum,S.mutans and total bacteria.4.ElISA was performed to determine the cytokine levels.[Results]1.P.g.and F.n.were most frequently detected,while less for S.m.2.P.gingivalis’ proportion from both sites was significantly higher than the other two bacteria(P<0.05),except for 2 weeks’ peri-implant sulcus sample.3.Bacteria counts from abutment screw cavities were always less than those from peri-implant sulcus and was significantly lower for total bacteria at 3 months(P<0.05).4.Total bacteria from abutment screw cavities significantly reduced at 3 months compared to baseline(P<0.05).5.ELISA showed IL-1β and TNF-α levels of all patients were decreased at 2 weeks and 3 months after treatment and reduction of IL-1β,TNF-α,IL-6 and IL-17 from 2 weeks to 3 months and from baseline to 3 months all showed a significant difference.[Conclusions]1.PDT appears to be an effective way reducing P.gingivalis with short time intervals,as well as decreasing total bacteria counts within abutment screw cavities in the long run,suggesting PDT an effective way sterilizing inner surfaces of oral implant suprastrutures.2.Denfotex PADTM light system can effectively reduce levels of IL-1β,TNF-α,IL-6,IL-17 in peri-implant sulcus indicating PDT an effective way preventing peri-implantitis.