Effect of 0.12% chlorhexidine on bacterial recolonization following periodontal surgery.

Bacterial plaque accumulation following periodontal surgery has been directly associated with delayed and altered surgical wound healing. Successful antimicrobial treatment following periodontal surgery depends upon the elimination and suppression of wound associated microorganisms. Highly effective antimicrobials should also prevent recolonization of periodontopathogens. In this investigation, the antimicrobial effect of a 0.12% chlorhexidine gluconate mouthrinse (Peridex) on bacterial recolonization after periodontal surgery was determined. A double-blind, randomized, placebo-controlled study was carried out on 40 patients for 6 weeks. Patients with moderate periodontitis (AAP Class III) underwent osseous periodontal flap surgery in one quadrant. Subgingival and marginal plaque samples from the surgery area were taken prior to surgery and 2 and 6 weeks postoperatively. General descriptive bacteriological cultural analysis and assays for specific microbial populations were carried out. During the 6 weeks of mouthrinse use, patients using chlorhexidine had significant reductions over placebo (P less than 0.05) in the number of total Gram-positive facultative cocci, streptococci (85.8%); Gram-positive facultative rods, primarily Actinomyces (91.7%); Capnocytophaga (97.6%) and Gram-negative anaerobic rods (94.5%). Few black pigmented Bacteroides or Actinobacillus actinomycetemcomitans were found prior to surgery or any time postoperatively. In the chlorhexidine group, 6 weeks post surgery, streptococci were the predominant bacterial group in the sampled plaque. Quantitatively, the distribution of bacteria, after 2 and 6 weeks of mouthrinse use, was consistent with a young, less mature plaque. A previous study demonstrated that this plaque was associated with clinical health.