The present invention for the first time discloses a method and a kit of parts for treating a periodontal disease, such as periimplantitis, gingivitis, periodontitis and/or periimplant mucositis, caused by microorganisms that colonize a tooth and/or implant surface at, above and/or below the gingival margin, and which reside in a biofilm either subgingival and/or supragingival, characterized by employing a surgical process leading to substantively removing, destroying, killing and/or disrupting and/or inhibiting growth and/or regrowth of a pathogenic biofilm at a site of a microbial infection in a patient suffering from a periodontal disease. Said method comprises, and said kit of parts comprises the means for； cleaning disinfecting and/or debriding the site of microbial infection mechanically and sequentially using first at least one cleaning and/or disinfecting agent with an immediate bactericidal effect, such as a NaClO solution, and thereafter at least one cleaning and/or disinfecting agent with a sustainable bactericidal effect, such as a CHX solution.
