Judy Fan-Hsu DDS, FAGD; Janet Southerland MPH
Smoking significantly increases the risk of failure in dental implants and augmentation procedures for implants.
This review supports a strong causal effect between smoking and dental implant failures with or without augmentation. There was limited evidence to determine an association with different implant surfaces.
1) Is there a significant risk of implant failure in smokers compared to nonsmokers? 2) Does smoking interfere with prognosis of dental implants that were placed with accompanying bone augmentation? 3) Does smoking increase the risk of failure for implants with different surfaces? And 4) Does smoking increase the risk of peri-implant inflammation and peri-implant bone loss?
A systematic literature search of two electronic databases (MEDLINE/PubMed and EMBASE) was performed. The search yielded a total of 64 articles (29 studies qualified for meta-analysis -15 prospective, 14 retrospective), and 35 were included for systematic review (1 randomized clinical trial, 11 prospective studies and 21 retrospective studies). Smoking was categorized for the meta-analysis group at a patient and implant level and further categorized based on observation periods of = 1 year; > 1; = 5 years, and > 5 years. In addition, the authors considered studies that involved implant-prosthetic rehabilitation after augmentation procedures to enhance bone quantity at the implant site.
The meta-analysis and systematic review indicated that smokers have more than twice the probability of implant failure than nonsmokers. This finding was independent of augmentation or implant surface. The reviews also found that enhanced peri-implant inflammation and bone loss affected smokers more than nonsmokers.
Smoking adversely affects dental implant longevity as well as bone augmentation (guided bone regeneration and sinus floor elevation and augmentation) accompanying implant therapy. In addition, more inflammation and bone loss occurred in smokers than nonsmokers. Five studies revealed no significant association of smoking with different implant surfaces.
Source of Funding:
The authors did not receive funding to conduct this review.
Importance and Context:
This review demonstrated that smoking more than doubles the risk of implant failure with or without bone augmentation. This study emphasized it is important to inform patients who smoke that their implants may fail because of their habit. It also opens the door for dentists to discuss with patients the risks associated with smoking and to provide them with smoking cessation help.
Strengths and Weaknesses of the Systematic Review:
This study used appropriate methods for identifying and selecting the studies. Although the authors did not conduct a search of the grey literature, they did conduct a comprehensive data evaluation. The authors also provided an assessment of heterogeneity and publication bias, as well as analyses of data at both patient and implant levels. To explore other potential confounding among groups, the review provided subsets of analyses. Frequencies for distribution of smokers and nonsmokers, gender, and implant sites in the maxillae or mandible were presented. One study weakness was that the analyses included retrospective, prospective, RCT, and cohort studies. Generally, studies of different types are analyzed separately.
Strengths and Weaknesses of the Evidence:
Out of the total of 64 publications that the authors identified, 29 were selected for meta-analysis and 35 for systematic review. A systematic review without meta-analysis usually provides qualitative outcomes. This qualitative outcome is informed by the quantitative outcomes of a meta-analysis. For this reason, it might make more sense to simply eliminate the qualitative narrative systematic review and focus solely on the quantitative systematic review with meta-analysis. Overall, evidence showed increased risk of implant failure associated with smoking as well as failure in smokers who had augmentation procedures associated with implant placement.
Implications for Dental Practice:
Dental implants are an important treatment option for tooth replacement. Given the increased risk for failure of implants in smokers, informed consent is critical so that the at-risk patient is clearly aware of the long term prognosis of the treatment. The dentist should offer other treatment options and provision of smoking cessation program.