Change in Subgingival Bacterial Recolonization Profiles Following Smoking Cessation

Introduction: Chronic periodontitis is a polymicrobial infection that leads to periodontal inflammation and can result in eventual tooth loss. 41.9% of periodontitis in the USA is attributable to smoking, and smokers are at a higher risk for more severe and extensive disease than non-smokers. Objectives: The purpose of the present study was to longitudinally examine shifts in microbial recolonization following smoking cessation in subjects with chronic periodontitis. Methods: 23 current smokers with generalized moderate to severe chronic periodontitis were enrolled to receive non-surgical therapy and smoking cessation counseling. Pooled subgingival plaque samples and clinical periodontal data were collected from all subjects from six sites with probing depths >=5mm and attachment loss >=7mm at baseline and at 3, 6 and 12 months following non-surgical therapy. Following genomic DNA isolation, the 16S rRNA gene was amplified using polymerase chain reaction with fluorescently labeled broad-range eubacterial primers. The amplicons were digested using HhaI and MspI restriction enzymes and Terminal Restriction Fragment Length Polymorphism Analysis (t-RFLP) was used to examine subgingival microbial profiles in each subject during recolonization over 3,6 and 12 months. Bray-Curtis similarity index was calculated based on peak areas and Analysis of Similarity (ANOSIM) was used to compare microbial profiles among quitters and non-quitters. Results: 11 subjects quit smoking following intervention, while 12 others continued to smoke. No differences were observed in clinical parameters between quitters and non-quitters at any time point. There was no difference in the microbial profiles of smokers and quitters at baseline. Statistically significant differences were observed in microbial profiles among quitters and non-quitters at all 3 time points (P<0.005). Conclusions: Smoking cessation is associated with a recolonization profile that is significantly different from baseline, while smoking appears to be associated with a recolonization profile similar to that of baseline.