Several implant surface
debridement methods have been reported for the treatment of
peri-implantitis, however, some of them can damage the implant surface or promote bacterial resistance.
Photodynamic therapy (
PDT) is a new treatment option for
peri-implantitis. The aim of this in vitro study was to analyze implant surface decontamination by means of
PDT. Sixty implants were equally distributed (n = 10) into four groups and two subgroups. In group G1 there was no decontamination, while in G2 decontamination was performed with
chlorhexidine. G3 (
PDT -
laser + dye) and G4 (
laser, without
dye) were divided into two subgroups each; with
PDT performed for 3 min in G3a and G4a, and for 5 min in G3b and G4b. After 5 min in contact with
methylene blue dye (G3), the implants were irradiated (G3 and G4) with a low-level
laser (GaAlAs, 660 nm, 30 mW) for 3 or 5 min (7.2 and 12 J). After the dilutions,
culture media were kept in an anaerobic atmosphere for 1 week, and then colony forming units were counted. There was a significant difference (p < 0.001) between G1 and the other groups, and between G4 in comparison with G2 and G3. Better decontamination was obtained in G2 and G3, with no statistically significant difference between them. The results of this study suggest that
photodynamic therapy can be considered an efficient method for reducing bacteria on implant surfaces, whereas
laser irradiation without
dye was less efficient than
PDT.