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

Objective The 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 12 months. Materials and Methods Forty subjects with initial peri‐implantitis, that is, pocket probing depths (PPD) 4–6 mm with bleeding on probing (BoP) and radiographic bone loss ≤2 mm, 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 12 months. 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. Results After 12 months, the number of BoP‐positive sites decreased statistically significantly (P