The influence of tobacco smoking on the outcomes achieved by root coverage procedures: An updated systematic review

Abstract Objective This updated version of a systematic review (SR) originally published in 2009 evaluated the effect of smoking on the clinical outcomes achieved with root coverage (RC) procedures in the treatment of gingival recession (GR) defects. Materials and Methods This SR includes randomized controlled trials, controlled clinical trials, and case series with a minimum follow‐up of 6 months. Eligible studies involved GR defects without interproximal tissue loss submitted to RC procedures, as well as outcome measures from smokers (i.e., those smoking 10 or more cigarettes per day at baseline) and nonsmokers, recorded separately. Three electronic databases were searched up to March 31, 2024. Random effects meta‐analyses were conducted thoroughly. Results A total of 12 studies reporting on 181 smokers and 162 nonsmokers, submitted to different RC procedures, were included. Half of these trials were originally included in the 2009 SR, whereas the other half (six studies) were included in this update. Nonsmokers experienced greater reductions in GR and gains in clinical attachment level compared to smokers. Pooled estimates comparing smokers and nonsmokers who received coronally advanced flap (CAF) alone and subepithelial connective tissue graft (SCTG) + CAF showed that nonsmokers achieved greater mean root coverage (MRC) in both treatments. Significant differences in MRC of 10.85% (95% CI, 1.92 to 19.77) and 22.04 (95% CI, 14.25 to 29.83), favoring nonsmokers, were identified for CAF and SCTG + CAF, respectively. Similarly, nonsmokers treated with SCTG + CAF displayed superior number of sites exhibiting complete root coverage (CRF) when compared with smokers (risk ratio, 4.12; 95% CI, 1.73 to 9.80). Conclusions Smoking negatively impacts the outcomes of RC procedures, particularly those achieved by SCTG‐based procedures. Clinical Significance Smoking was linked to poorer RC outcomes. These outcomes highlight the critical need to integrate smoking cessation into periodontal treatment plans.