Objectives: The aim of the study was to identify risk indicators for apical periodontitis (AP) in the individual. A parameter was defined as a 'risk indicator' when its presence increased the individual's risk of exhibiting AP. Risk indicators may, but need not be directly associated with the disease.
Methods: The study included full-mouth surveys of 613 randomly selected individuals, who were 20-60 years old and living in Aarhus County. Logistic regression analyses were performed. The outcome variable was >or=1 AP/no AP. The independent variables were obtained from information on socioeconomic and dental status.
Results: It was found that smoking, no usage of services from the dentist, >or=2 secondary caries lesions, >or=3 inadequate coronal fillings and the presence of root filling(s) were statistically associated with AP. A separate analysis for individuals with no previous root fillings showed that individuals with regular dental visits as well as individuals who had all their teeth (third three molars excluded) were less likely to have AP, whereas individuals who had >or=3 inadequate coronal fillings were more likely to have AP.
Conclusions: The results from the present study of a Danish population showed that the most important risk indicator of having AP in the individual was the radiographic evidence of root fillings. The presence of several caries lesions, the quality of the dental treatment, the regularity of dental visits and smoking were also statistically associated with AP. Further, the socioeconomic status of the individual did not provide much additional information on the periapical status.