The Impact of Smoking on Dental Implant Success, Peri-Implantitis, and Marginal Bone Loss: A Systematic Review

Background: Dental implants are a reliable and widely used approach for tooth replacement. However, their long-term success can be influenced by several biological and behavioral risk factors. Among these, smoking represents a major modifiable factor known to interfere with osseointegration, wound healing, and peri-implant tissue integrity. This systematic review aimed to evaluate the influence of smoking on dental implant success rates, peri-implantitis occurrence, and long-term implant stability in adult patients. Methods: A comprehensive search was conducted across PubMed, Scopus, and Cochrane Library databases for studies published up to [insert month, year]. Clinical and observational studies comparing smokers and non-smokers receiving dental implants were included. The primary outcomes were implant failure rate, peri-implantitis occurrence, and marginal bone loss. Data were extracted and synthesized narratively due to heterogeneity in study design and reporting. Risk of bias was evaluated using the Newcastle–Ottawa Scale for observational studies. Results: Twenty-five studies met the inclusion criteria. Implant failure was significantly higher among smokers (8.9–10.2%) than non-smokers (3.7–4.5%), with reported odds ratios above 2.0. The prevalence of peri-implantitis was also greater in smokers (30.5–37.6%) compared with non-smokers (16.4–18.4%), corresponding to risk ratios up to 2.79. Smokers exhibited additional marginal bone loss of approximately 0.33–0.51 mm. Conclusion: Smoking substantially increases the risk of implant failure, peri-implantitis, and marginal bone loss, thereby reducing implant longevity. Smoking status should be considered a critical factor in preoperative assessment, treatment planning, and patient education to enhance implant success. The review included heterogeneous observational data with variability in follow-up duration, diagnostic criteria, and reporting standards, which limited the ability to perform a meta-analysis.