The effect of supragingival biofilm re-development on the subgingival microbiota in chronic periodontitis

Abstract

ObjectiveIn this study, we hypothesized that in the absence of oral hygiene, re-growth of the climax microbial communities of supra and subgingival biofilm happens in a faster and more intense fashion in individuals with chronic periodontitis (CP) compared to periodontally healthy controls (PH). DesignThirty patients (PH=15 and CP=15) received professional supragingival prophylaxis, and were asked to refrain from oral hygiene for 7days. Supra and subgingival biofilm samples and GCF were collected from randomly selected quadrants at baseline (before prophylaxis), immediately after prophylaxis, 2h, 6h, 24h, and 7days after prophylaxis. The composition of the biofilm was determined by the checkerboard method. ResultsAll subjects developed gingivitis at the end of 7days without oral hygiene. GCF mean volumes were significantly higher in CP than PH patients at baseline, but they started decreasing 2h after prophylaxis, returning to baseline levels after 24h in both groups. Significant increases in mean counts for most of the species evaluated were observed in both groups and biofilms over time (p<0.05). Few hours after prophylaxis, a more marked reduction in microbial counts happened in the supragingival biofilm of the CP group, and re-development of biofilm started later than in the PH group. At 7days, no differences were seen between groups. Significant differences in kinetics of re-colonization between groups were observed only in the subgingival biofilm for T. denticola and F. nucleatum ss vicentii (increased in the CP), and N. mucosa (increased in the PH group; p<0.05). ConclusionsBiofilm re-development was very similar between CP and PH individuals, although microbial re-growth occurred few hours earlier in PH than PC. Only 3 species in the subgingival biofilm differed in re-colonization between groups. Thus, we reject the hypothesis that re-colonization of biofilm in CP patients is more intense and faster than in individuals with PH.