[Prevalence of the various types of periapical lesions and the significance of histologic evaluation].

To determine the prevalence of radicular cyst and chronic apical periodontitis among human periapical lesions 299 lesions were analysed during the past 6 years. The specimen were obtained during extraction or endodontic surgery. Of the lesions assessed, 195 (65.2%) were found histopathologically to be cystic, 96 (32.1%) were diagnosed as chronic apical periodontitis and 8 (2.7%) were observed as "other lesion". Studies to determine the diagnostic features and prevalence of these lesions have failed to reach a consensus view, though the treatment and the prognosis may differ to the lesion present.