Effects of Smoking on Clinical and Microbiological Response Following Non‐Surgical Periodontal Treatment in Periodontitis Patients

Objectives This study aimed to compare the distribution of subgingival periodontal pathogens following the non‐surgical periodontal treatment (NSPT) in smoking and non‐smoking periodontitis patients. Methods A total of 48 patients (24 smokers and 24 non‐smokers) with stage III/IV, grade B/C periodontitis were included and NSPT was performed. Clinical measurements were recorded, and subgingival plaque samples were obtained from periodontal pockets at the onset and after 4 weeks of treatment. The level of periodontopathogens was determined by a polymerase chain reaction‐based method. Clinical and microbiological data were analysed by using Chi‐square, Student‐ t and Pearson correlation tests. Results The levels of periodontopathogens (except Eikenella corrodens and Capnocytophaga spp.) diminished significantly following NSPT ( p < 0.05). Although the decrease in the levels of periodontopathogens was lower in smokers, the difference was statistically insignificant except for Tannerella forsythia . A statistically significant reduction was recorded for all clinical parameters following NSPT ( p < 0.001). The rate of decrease in non‐smokers was higher, but this difference was statistically insignificant ( p > 0.05). Only the reduction in pocket depth was higher in non‐smokers ( p < 0.05). Conclusions The present findings indicate that smoking did not significantly impact subgingival microflora, except for Tannerella forsythia , although the elimination of certain periodontopathogens proved more challenging in smokers following NSPT. Furthermore, among the changes in clinical parameters, a statistically significant difference was observed only in the changes in pocket depth. Trial Registration ClinicalTrials .gov identifier: NCT06383455