Background: Smoking is a major risk factor for periodontitis and tooth loss. Smoking cessation has a positive impact in periodontal treatment. However, so far, no systematic review has evaluated the effect of smoking cessation on tooth loss. Therefore, this review aimed to evaluate if smoking cessation reduces the risk of tooth loss. Methods: Observational (cross-sectional and longitudinal) studies that investigated the association between smoking cessation and tooth loss were included. MEDLINE, EMBASE and LILACS databases were searched for articles published up to November 2018. Pooled results for subgroups of current and former smokers were compared in meta-analysis. Meta-regression was used to test the influence of smoking status on estimates and explore the heterogeneity. Results: Of 230 potentially relevant publications, 21 studies were included in the qualitative review and 12 in the quantitative analysis. Meta-analysis of cross-sectional studies did not show any differences between former and current smokers in the chance of losing 1 or more teeth (OR = 1.00; 95% CI = 0.80 to 1.24, I² = 80%), losing more than 8 teeth (OR = 1.02; 95% CI = 0.78 to 1.32, I² = 0%) or being edentulous (OR = 1.37; 95% CI = 0.94 to 1.99, I² = 98%). Meta-analysis from longitudinal studies showed that, when compared to never smokers, former smokers presented no increased risk of tooth loss (RR = 1.15; 95% CI = 0.98 to 1.35, I² = 76%), while current smokers presented an increased risk of tooth loss (RR = 2.60; 95% CI = 2.29 to 2.96, I² = 61%). Meta-regression showed that, among former smokers, the time of cessation was the variable that better explained heterogeneity (approximately 60%). Conclusions: Risk for tooth loss in former smokers is comparable to that of never smokers. Moreover, former smokers have a reduced risk of tooth loss, when compared to current smokers.

Background: Patients with diabetes present a worse response to periodontal treatment. Local antimicrobials as an adjunct to scaling and root planing (SRP) provide additional benefits in the treatment of periodontitis in healthy patients. This review aims to evaluate the effects of local antimicrobials as an adjunct to SRP, compared with SRP alone, on periodontal clinical parameters of patients with chronic periodontitis (CP) and diabetes mellitus (DM).Methods: Only randomized controlled trials with: 1) at least 6 months of follow‐up; 2) SRP, in combination with local antimicrobials; and 3) patients with periodontitis and DM were considered eligible. MEDLINE, EMBASE, and LILACS databases were searched for articles published up to January 2016. Random‐effects meta‐analyses were conducted for clinical attachment level (CAL), probing depth (PD), bleeding on probing, and gingival index change after treatment.Results: Of 153 papers potentially relevant to this review, six were included. The majority of trials showed a significant PD reduction and CAL gain associated with use of local antimicrobials in patients with type 1 and type 2 DM. Only studies that included well‐controlled patients and applied antimicrobials at the deepest sites or sites with baseline PD ≥5 mm presented significant PD reduction and CAL gain.Conclusion: In patients with DM and CP, use of local antimicrobials as an adjunct to SRP may result in additional benefits compared with SRP alone in PD reduction and CAL gain, especially in well‐controlled individuals and deep sites.