Implant surface decontamination is considered a highly susceptible step in the treatment of peri-implantitis. The application of 35% phosphoric acid after mechanical debridement is superior to mechanical debridement combined with sterile saline rinsing for decontamination of the implant surface during surgical peri-implantitis treatment. However, phosphoric acid as implant surface decontaminant does not seem to enhance clinical outcomes on a 3-month follow-up. Larger studies with a longer follow-up period are needed to validate these findings.