Kaffe I, Tamse A, Littner M M, Schwartz I
Oral Surg Oral Med Oral Pathol. 1984 Jul;58(1):109-12. doi: 10.1016/0030-4220(84)90374-8.
A radiographic statistical study was performed in order to determine the presence and type of external resorption found in pulpless permanent teeth. Of 1,372 roots evaluated, 49.6% showed resorption. The degree of apical external resorption was significantly related to the presence and size of the periapical lesions in all roots. Much more resorption was found in the roots without root canal filling than in those that were filled.
