Background: This article critically appraises a systematic review that was conducted in 2015 to evaluate implant survival, postoperative infection, and marginal bone loss (MBL) in smokers compared with nonsmokers.
Clinical question: In patients undergoing implant placement, are smokers at higher risk than nonsmokers for implant failure, postoperative infection, and MBL?
Summary of methods: An electronic search was conducted in three databases in addition to hand searching without date or language restrictions. All studies, including randomized controlled trials, nonrandomized controlled trials, and retrospective studies, were included in this review. Results were expressed as risk ratios for dichotomous outcomes (implant failure and postoperative infection) and as mean differences for continuous outcomes (MBL). A fixed-effects model was used in meta-analysis for studies with low homogeneity, while a random-effects model was used for those with high heterogeneity.
Critical appraisal: The review met all requirements on the AMSTAR checklist. The overall quality of evidence is low, as the review includes both randomized and nonrandomized trials in addition to retrospective studies. Due to the many uncontrolled confounders, the results should be interpreted with caution.
Practical implications: Because of the possible association between smoking and increased rates of implant failure, postoperative infection, and MBL, caution is warranted when considering dental implants in patients who smoke.