Association between smoking cessation and periodontitis progression: a systematic review and meta-analysis of prospective observational studies.

AIM: This systematic review and meta-analysis aimed to investigate the association between smoking cessation and periodontitis progression by comparing periodontal outcomes in patients who quit smoking vs. those who continued smoking. METHODS: PubMed, Embase, and the Cochrane Library were searched for prospective studies (published up to March 2025) on smoking cessation and periodontitis progression, with ≥3 months' follow-up. The primary outcome was probing depth. R Studio 4.1.3 was used for random-effects meta-analyses, sensitivity, and subgroup analyses. RESULTS: Six studies (n = 1,934) were included. Smoking cessation was associated with short-term improvements in PD at 3 months (SMD = -1.08, 95%CI = -1.84 to -0.31, P < 0.01) and 6 months (SMD = -1.50, 95%CI = -2.45 to -0.55, P < 0.01), as well as CAL at 3 months (SMD = -0.78, 95%CI = -1.39 to -0.16, P = 0.01). However, these associations were not sustained at 12 months (PD: P = 0.10; CAL: P = 0.27). No significant associations were observed for BOP or PI at any follow-up interval. CONCLUSION: Smoking cessation may be associated with modest short-term improvements in periodontal parameters, particularly PD and CAL. However, further high-quality studies with longer follow-up are warranted to confirm clinical relevance.