Comparison of Modalities to Disinfect Dental Implants

Objective: Peri-implantitis is an oral infection leading to loss of dental implants. Disinfection of the implant surface is thought to be an important step in the treatment of peri-implantitis. Accordingly, this in vitro study compared four different protocols to disinfect dental implant surfaces. Methods: Round titanium discs (10 mm x 1 mm) were placed into BHI broth to which had been added 10 ml of whole mixed saliva. The discs were incubated for 24h at 37⁰C. They were vigorously rinsed to remove non-adherent microorganisms and they were then treated with either; 1) a diode laser (Odyssey, Ivoclar); 2) 1% citric acid for one minute; 3) photofrin (porfimer sodium) for 45 mins followed by exposure to a 630 nm laser (photodynamic therapy); or, 4) ultraviolet light for 10 min. The discs were then examined by scanning electron microscopy to assess the titanium surface area covered by microorganisms. All treatments were performed in triplicate. Following treatment, one disc from each group was placed in BHI broth for 24h at 37⁰C and then vortexed to disperse any adherent bacteria. Then 0.1 ml aliquots were anaerobically cultured on blood agar media for 48-72 hours at 37⁰C and the number of colonies was enumerated. Positive controls included untreated contaminated discs and negative controls included untreated sterile discs. Results: Compared to the positive controls or to contaminated discs treated with 1% citric acid, photodynamic therapy or ultraviolet light, scanning electron microscopy showed that the diode laser-treated titanium discs had a much lower proportion of surface area colonized by microorganisms. Conclusions: Diode laser treatment was effective in vitro in reducing bacterial colonization of titanium surfaces. Diode laser treatment may be efficacious in vivo in disinfecting dental implants in the treatment of peri-implantitis.