Risk indicators for a reduced marginal bone level in the individual

The aim of this study was to assess risk indicators for reduced marginal bone level in the individual, with emphasis on apical periodontitis.

Six hundred and sixteen randomly selected Danish adults (304 women and 312 men), mean age of 42 years, underwent a full-mouth radiographic survey. The marginal bone level was measured from the cemento-enamel junction to the marginal bone. The measurements were performed at the mesial (Am) and distal (Ad) aspect of the tooth. The marginal bone level for each individual was calculated: Aind = sigma Ateeth/nteeth, and Aind > or =4 mm was considered as reduced marginal bone level. The periapical status was assessed by the periapical index (PAI), which was dichotomised (healthy = PAI scores 1 and 2, and diseased = PAI scores 3, 4 and 5). Coronal restorations (crowns, fillings and inlays) and smoking status were also recorded. All variables were analysed in a logistic regression model with reduced marginal bone level as the outcome.

The impact of age (odds ratio (OR) = 3.3), smoking (OR = 10.5) and apical periodontitis (OR = 4.7) on reduced marginal bone level was statistically significant (p < 0.01).

Not surprisingly, this study showed that smoking and older age were risk indicators for having reduced marginal bone level > or =4 mm. Even when adjusted for these factors, individuals with > or =1 tooth with apical periodontitis were five times more at risk of having a reduced marginal bone level than those with no periapical infection.