Smoking cessation is beneficial for periodontal maintenance patients

Rosa EF, Corraini P, Inoue G, Gomes EF, Guglielmetti MR, Sanda SR, Lotufo JP, Romito GA, Pannuti CM. Effect of smoking cessation on non-surgical periodontal therapy: results after 24 months. J Clin Periodontol. 2014 Dec;41(12):1145-53. doi: 10.1111/jcpe.12313. Epub 2014 Nov 21. PMID: 25265872.

1. According to Hill’s considerations for inferences of causation, there is accumulating evidence for the role of smoking in the aetiology of periodontitis. Thereby, association between smoking and periodontal diseases was moderate to strong in cross-sectional and case-control studies. Temporality was evidenced by cohort studies, in which smokers presented higher clinical attachment loss and greater radiographic bone loss than non-smokers. The biologic gradient was such that heavy smokers presented with higher attachment loss than light smokers.
2. Differences in biofilm composition and host immune response between smokers and non-smokers are among the most biological plausible explanations for the associations found. These associations were coherent with the current knowledge of the natural history of periodontal diseases and analogously, adverse effects of smoking were also evidenced on general health.
3. 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.
4. 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. 
5. 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). 
6. At 3 months of follow-up, Q presented a significantly higher mean CAL-dif gain in comparison with NQ. Hence, Q presented a greater reduction in %CAL ≧3mm , which is a more clinical meaningful outcome. 
7. Even though in clinical practice the magnitude of the difference in CAL and PD between Q and NQ after NSPT seems discrete at 24 months, it must be regarded as sufficiently optimistic. It represents the beginning of a slow process of improvement that can also encourage the patient to a life-style change towards better oral and general health care. Smoking cessation can make Q more self-conscious about their oral health, which can lead to lifestyle change. 

8. In conclusion, after 24 months of follow-up periodontitis patients who successfully quit smoking showed a better response to NSPT than continuing smokers.