Association of tobacco use and periapical pathosis - a systematic review.

The aim was to review the current evidence regarding an association between tobacco use, that is, cigarette smoking, and periapical pathosis. A systematic MEDLINE search of articles published prior to October 2011 (4th) was conducted using the keywords 'smoking and endodontics OR smoking and periapical index'. The study selection, data preparation and validity assessment were conducted by two reviewers. Nine studies fulfilled the inclusion criteria and represented data from 3008 individuals. The studies differed with respect to (i) study design, (ii) radiographic techniques, (iii) assessment of periapical pathosis, (iv) classification of smoking characteristics and/or (v) potential confounders accounted for in the analyses. Five of six cross-sectional studies revealed a significant positive association (OR 1.35-16.8) between periapical pathosis and current cigarette smoking. One of three longitudinal studies indicated an increased risk (OR 1.7) of root treated teeth for current smokers. The substantial heterogeneity of the included studies limited their interpretation. Further, well-designed studies are required to investigate the association between tobacco use and periapical pathosis.