Related Experiment Video
Updated: Apr 3, 2026

Inducing Apical Periodontitis in Mice
Published on: August 6, 2019
Radiographic and histological evaluation of persistent periapical lesions associated with endodontic failures after
M K Çalışkan1, M E Kaval2, U Tekin3
1Department of Endodontology, School of Dentistry, Ege University, Izmir, Turkey.
Aim:
To determine the histology of persistent periapical lesions associated with nonsurgical endodontic treatment failures and to compare radiographically the sizes of periapical lesions and the presence or absence of the radiopaque lamina with the histological findings.
Methodology:
Ninety-three anterior teeth designated for apical microsurgery were included in the study. After taking standard radiographs of all cases using the parallel technique, the films were scanned and evaluated for the size of periapical radiolucent lesions and the presence or absence of radiopaque lamina by two calibrated observers. Biopsy specimens were obtained during apical microsurgery and examined under light microscopy by oral pathologists. Histological analysis established diagnoses of granuloma, cyst, abscess and scar tissue. Interobserver agreement was evaluated by the kappa test, and the relationship between histological diagnosis and lesion size was analysed by the Pearson's chi-square test.
Results:
The 93 specimens consisted of 72% periradicular granulomas; 21.5% radicular cysts, including two keratocysts; 4.3% abscesses; and 2.2% scar tissue. Cystic prevalence increased as the size of the periapical lesion increased; however, there was no correlation between the presence of a radiopaque lamina and histological diagnosis of cyst.
Conclusions:
Neither radiographic size nor presence of an associated radiopaque line alone was sufficient to determine the type of lesion. Histological examination is required in order to reach to a definitive diagnosis.

