Impact of smoking cessation on periodontitis: A systematic review and meta-analysis of prospective longitudinal observational and interventional studies.

Aims: This systematic review aimed to estimate the effect of tobacco smoking cessation on the risk for periodontitis compared to the risk among never-smokers and to evaluate the effect of tobacco smoking cessation on the clinical outcomes of non-surgical periodontal treatment.

Methods: Electronic searches were performed in PubMed, Scopus and Embase. Search strategy included MeSH and free terms: periodontitis, periodontal diseases, smoking, tobacco use, tobacco, tobacco products, cigarette, pipe and cigar. Only original prospective longitudinal observational and interventional studies that investigated the association between smoking and periodontitis onset or progression were included. Meta-analyses were conducted to summarize the evidence.

Results: 2,743 articles were identified in electronic searches; out of which only six were included in the meta-analysis. Pooled estimates showed that the risk of periodontitis incidence or progression among those who quitted smoking was not significantly different from the risk for never-smokers (RR 0.97; 95% CI 0.87-1.08). Smokers had approximately 80% higher risk of periodontitis than quitters (RR 1.79; 95%CI 1.36-2.35) and never-smokers (RR 1.82; 95%CI 1.43-2.31). Periodontal therapy resulted in up to 0.2 mm (95%CI -0.32;-0.08) higher gain in attachment level and extra 0.32 mm (95%CI 0.07;0.52) reduction in pocket depth among quitters over non-quitters after short follow-up (12-24 months).

Conclusions: Few studies on the topic were identified. Smoking cessation reduced the risk for periodontitis onset and progression, and improved the outcomes of nonsurgical periodontal therapy.

Implications: This review provides the first quantitative evidence of the impact of smoking cessation on the risk for periodontitis onset and progression. The findings have demonstrated that the risk for periodontitis becomes comparable to that of never-smokers and that nonsurgical periodontal treatment outcomes improve after smoking cessation. Dental professionals ought to consider smoking cessation interventions as a relevant component of the periodontal therapy.