Treating Peri-implantitis With Novel Chitosan-Antimicrobial Mixtures

Objectives: Peri-implantitis is a significant clinical issue plaguing implant patients in increasing numbers, and is the most common reason for implants to fail. Currently, there is no proven method for disinfection of implant surfaces or the surrounding socket after peri-implantitis develops. Our objective was to develop a novel way to reduce bacterial viability in peri-implantitis sites by applying chitosan hydrogel fused with antimicrobial products into implant socket defects.
Methods: The ability of chitosan antimicrobial hydrogels to kill bacterial biofilms on implants was tested using a pig jaw model. Commercially available titanium implants were colonized with Enterococcus faecalis biofilms by overnight incubation of implants in broth culture. These implants were then placed within a pig jaw post extraction of the pig teeth and sockets prepared with implant drills to create circumferential defects around implants representing the most common intrabony defect of peri-implantitis. Once the implants were placed, heat-gelling chitosan mixtures containing antimicrobials were placed around the implant platform and allowed to penetrate the socket. After 2 days the implants were removed from the jaw, and were stained with fluorescent dyes to visualize live/dead bacteria and chitosan coating. The implants were imaged using confocal microscopy. The socket bone was recovered and also stained for confocal imaging, and bacterial counts were recovered from bone to assess bacterial viability.
Results: Chitosan hydrogels were able to penetrate to the implant socket and reach the tip of the implant. The presence of chitosan with or without antimicrobials had a protective effect on the socket bone, with significantly less biofilm and viable counts recovered from bone and implant treated with chitosan+ampicillin+metronidazole compared to the infected implant control.
Conclusions: Using a pig jaw model, we have begun to develop a promising method for in situ treatment of peri-implantitis.