Prevalence of apical periodontitis in root filled teeth: findings from a nationwide survey in Finland

Aim To assess the prevalence of apical periodontitis in the Finnish population aged 30 years and older and relate it to the technical quality of root filling by the type of tooth. Methodology As part of the Finnish nationwide Health 2000 study, panoramic radiographs were used of the dentate subjects (n = 5335) aged 30–95 years (mean 50.2 years) to assess the apical and endodontic status of their teeth (n = 120635). Apical periodontitis (AP) was recorded when the periodontal ligament space was more than double in width, or loss of lamina dura or a periapical radiolucent lesion was seen. Technically, adequate root fillings had a gap of 0–3 mm from the apex; all others were defined as inadequate. Statistical methods included chi‐square tests and anova. Risk of AP was estimated as cross‐product odds ratio and its 95% confidence interval. Results Teeth with AP occurred in 27% of the dentate subjects being more prevalent in subjects with root filled teeth than in those without (39% vs. 9%; P