Effect of smoking cessation on non-surgical periodontal therapy: results after 24 months

Aim: The aim of this 24-month prospective study was to assess the effect of smoking cessation on non-surgical periodontal therapy (NSPT) in adult subjects with chronic periodontitis. Materials and Methods: Relative to a previous 12-month follow-up study, recruitment and follow-up period were extended, resulting in 116 eligible among the 286 screened subjects. They received NSPT and concurrent smoking cessation interventions. Periodontal maintenance was performed every 3 months. A calibrated examiner, blinded to smoking status, performed full-mouth periodontal examination in six sites per tooth at baseline, 3, 12 and 24 months of follow-up. Expired air carbon monoxide concentration measurements and interviews were performed to gather demographic and behavioural information. Results: From the 116 enrolled subjects, 61 remained up to 24 months of follow-up. Of these, 18 quit smoking (Q), 32 continued smoking (NQ) and 11 oscillated (O) at 24 months of follow-up. Thereby, Q showed significantly higher mean CAL gain in diseased sites and higher reduction in the proportion of sites with CAL >= 3 mm, when compared to NQ. In addition, Q presented significantly higher mean probing depth reduction relative to NQ(p <= 0.05). Conclusion: Smoking cessation promoted additional benefits on NSPT in chronic periodontitis subjects.