Anti-infective therapy of peri-implantitis with adjunctive local drug delivery or photodynamic therapy: 12-month outcomes of a randomized controlled clinical trial

ObjectiveThe objective of the study is to compare the clinical, microbiological and host-derived effects in the non-surgical treatment of initial peri-implantitis with either adjunctive local drug delivery (LDD) or adjunctive photodynamic therapy (PDT) after 12months. Materials and MethodsForty subjects with initial peri-implantitis, that is, pocket probing depths (PPD) 4-6mm with bleeding on probing (BoP) and radiographic bone loss 2mm, were randomly assigned to two treatment groups. All implants were mechanically debrided with titanium curettes and with a glycine-based powder airpolishing system. Implants in the test group (N=20) received adjunctive PDT, whereas minocycline microspheres were locally delivered into the peri-implant pockets of control implants (N=20). At sites with residual BoP, treatment was repeated after 3, 6, 9 and 12months. The primary outcome variable was the change in the number of peri-implant sites with BoP. Secondary outcome variables included changes in PPD, clinical attachment level (CAL), mucosal recession (REC) and in bacterial counts and crevicular fluid (CF) levels of host-derived biomarkers. ResultsAfter 12months, the number of BoP-positive sites decreased statistically significantly (P<0.05) from baseline in both groups (PDT: 4.031.66-1.74 +/- 1.37, LDD: 4.41 +/- 1.47-1.55 +/- 1.26). A statistically significant (P<0.05) decrease in PPD from baseline was observed at PDT-treated sites up to 9months (4.19 +/- 0.55mm to 3.89 +/- 0.68mm) and up to 12months at LDD-treated sites (4.39 +/- 0.77mm to 3.83 +/- 0.85mm). Counts of Porphyromonas gingivalis and Tannerella forsythia decreased statistically significantly (P<0.05) from baseline to 6months in the PDT and to 12months in the LDD group, respectively. CF levels of IL-1 decreased statistically significantly (P<0.05) from baseline to 12months in both groups. No statistically significant differences (P>0.05) were observed between groups after 12months with respect to clinical, microbiological and host-derived parameters. ConclusionsNon-surgical mechanical debridement with adjunctive PDT was equally effective in the reduction of mucosal inflammation as with adjunctive delivery of minocycline microspheres up to 12months. Adjunctive PDT may represent an alternative approach to LDD in the non-surgical treatment of initial peri-implantitis.