The effect of smoking on periodontal bone regeneration: a systematic review and meta-analysis.

Background: The effect of smoking on soft tissues after periodontal treatment has been extensively studied. However, little focus has been placed on the impact of smoking on bone regeneration after treatment. The aim of this review is to systematically assess the effect of smoking on bone regeneration after periodontal treatment.
Methods: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction, and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies assessing bone regeneration in smokers and non-smokers after periodontal therapy were selected. In addition, arms of clinical trials comparing different interventions that reported results separately for smokers and non-smokers were also included. Primary outcome measures were based on clinical and/or radiographic indicators of bone regeneration after periodontal therapy. The review and meta-analysis followed many of the recommendations outlined in the preferred reporting items for systematic reviews and meta-analyses statement.
Results: Six of 10 studies included in this review concluded that smoking negatively influenced bone regeneration. A meta-analysis of a subgroup of three studies demonstrated that smoking resulted in significantly less bone gain (P = 0.03) as measured by a change in the probing bone level after the treatment of intrabony defects with guided tissue regeneration. The meta-analysis showed a standardized mean difference of -2.05 (95% confidence interval: -2.64 to -1.47) using the random-effects model.
Conclusions: Smoking has a negative effect on bone regeneration after periodontal treatment. Patients should be advised that their smoking habit may result in poorer bone regeneration after periodontal treatment.