Increase in cariogenic bacteria after initial periodontal therapy.

This study examined the hypothesis of an intra-oral shift, during initial periodontal therapy, from a periopathogenic to a cariogenic flora. Seventy-one patients with periodontitis were randomly allocated to one of the following treatment strategies: (1) scaling and root planing, quadrant by quadrant, at two-week intervals (NC); (2) full-mouth scaling and root planing within 24 hrs (FRP); or (3) full-mouth disinfection within 24 hrs, including antiseptics [chlorhexidine (CHX) or amine fluoride/stannous fluoride (F) for 2 mos, or CHX for 2 mos followed by F for 6 mos (CHX+F)]. At baseline and after 2, 4, and 8 mos, bacterial samples were taken from supra- and subgingival plaque, saliva, and tongue. The detection frequencies and relative proportions of Streptococcus mutans increased in the NC and FRP groups, but decreased in the F group. In the CHX group, these species disappeared temporarily, but they disappeared for the entire 8 mos in the CHX+F group. These observations were similar for all sample locations. The periopathogens decreased in all groups. This finding confirms the abovementioned hypothesis and indicates a need for caries prophylactic regimens.