The short-term effect of apically repositioned flap surgery on the composition of the subgingival microbiota

The purpose of this investigation was to examine the short-term effect of a pically repositioned flap surgery on clinical and microbiologic parameters in patients with adult periodontitis. A total of 11 patients with moderate to advanced periodontitis received apically repositioned nap surgery. Subje cts were monitored during a 3-month pretreatment phase, the baseline surgic al phase, and for 3 months post surgery: Clinical assessments including pla que accumulation gingival redness, suppuration bleeding on probing, pocket depth, and attachment level were made at 6 sites per tooth. Subgingival pla que samples were taken from the mesial aspect of each tooth and the presenc e and levels of 29 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and percent age of sites colonized by each species (prevalence) were computed for each subject at each visit After surgery there was a significant decrease in mea n pocket depth and percentage of sites exhibiting gingival redness. Signifi cant decreases were seen in the percentage of sites that had attachment lev els < 4 mm, with a significant increase in the percentage of sites with att achment levels of 4 to 6 mm after therapy. The mean total DNA probe count f or all bacterial species was significantly decreased by both scaling and ro of planing and surgical therapy P gingivalis and B forsythus, 2 bacteria pr eviously shown to be susceptible to mechanical therapy exhibited statistica lly significant decreases in mean total DNA probe count. Because surgical t herapy decreased levels of the suspected periodontal pathogens C rectus, P nigrescens, and C gracilis. it may be speculated that there was a potential added beneficial effect of surgery on the periodontal microbiota.