SEM evaluation of the apical external root surface of teeth with chronic periapical lesion.

The aim is to verify, under scanning electron microscopy, the occurrence of apical root resorption in anterior and posterior teeth with chronic and radiographically visible periapical lesions. Thirty-two teeth were extracted, the apical thirds (n = 39) were removed, and prepared to analyse the external apical root surface. All specimens presented irregular areas of root resorption with different depths, located mainly around the apical foramen.