Bacteria infection is considered a major factor in the etiology of periodontal disease. The conventional periodontal phase 1 therapy often consists of 4 consecutive sessions of scaling and root planing at two-week interval. During this interval, a recently debrided pocket might be recolonized by pathogens from remaining untreated pockets, or from other ecologic niches, if cross-contamination occurs in the mouth. Recently, Quirynen and coworkers suggested a novel approach, i.e. full mouth disinfection, to enhance the treatment outcome. This paper provides a review of associated articles and makes relative discussion.