Mechanical Therapy With Adjunctive Minocycline Microspheres Reduces Red‐Complex Bacteria in Smokers

Background: Smoking increases the risk for periodontal disease and reduces the healing response. We examined the antimicrobial and clinical effects of scaling and root planing (SRP) with and without minocycline HCl 1 mg microspheres (MM) relative to smoking status in subjects with periodontitis. Methods: A total of 127 subjects (46 never smokers, 44 former smokers, and 37 current smokers) with moderate to advanced periodontitis were randomized to receive MM + SRP (N = 62) or SRP alone (N = 65). Subgingival plaque samples collected at baseline and day 30 were examined for the presence of 40 periodontal bacteria by DNA probe analysis. Results: MM + SRP reduced red‐complex bacteria (RCB) numbers and proportions to a greater extent than SRP alone, irrespective of smoking status. RCB numbers were not reduced by SRP in current smokers. The difference in the reduction in numbers of RCB by SRP relative to MM + SRP in current smokers was statistically significant (P