Aim: To evaluate the efficacy of adjunctive/alternative photo/mechanical and physical implant-surface decontamination approaches compared to standard instrumentation in conjunction with surgical peri-implantitis treatment. Materials and Methods: Randomized controlled clinical trials (RCTs) and controlled clinical trials investigating the efficacy of adjunctive or alternative photo/mechanical/physical measures for implant surface decontamination in conjunction with surgical peri-implantitis treatment without (PICOS 1) or with (PICOS 2) additional decontamination methods performed in test and control groups with changing inflammation parameters were covered. Changes in bleeding scores (i.e., bleeding index, or bleeding on probing [BOP]), suppuration, and probing depth (PD) were considered the primary outcomes. Results: Six articles describing five original RCTs were eligible for analysis. Based on two RCTs, the adjunctive/alternative use of air polishing with glycine or erythritol powder did not improve BOP reduction compared to standard instrumentation (PICOS 1). Based on one RCT, alternative use of titanium brushes resulted in significantly higher BOP reduction compared to either air polishing or standard instrumentation (PICOS 1). During reconstructive therapy and as an adjunct to implantoplasty, use of a titanium brush did not have any benefit on the BOP and mean PD reductions compared to the control group (i.e., implantoplasty + mechanical and chemical implant surface decontamination; one RCT; PICOS 2). Use of the Er:YAG laser resulted in significantly higher PD reduction after 6 months (one RCT), whereas no difference between the test and respective controls could be detected after 1 and 2 years (one RCT). Additionally, the use of the Er:YAG laser was not associated with improved BOP reductions over respective controls (two RCTs; PICOS 2). Conclusions: Owing to the limited available data, clinical efficacy of photo/mechanical and physical implant surface decontamination in conjunction with surgical peri-implantitis therapy is inconclusive. However, titanium brushes may be beneficial in reducing signs of inflammation.