Vertical root fractures of endodontically treated posterior teeth: A histologic analysis with clinical and radiographic correlates.

Vertical root fractures (VRFs) usually develop slowly, unnoticed by the patient until clinical signs and symptoms become apparent. In endodontically treated teeth, a VRF is a typical cause for extraction. The objective of the present study was the histologic analysis of VRFs in extracted, endodontically treated premolars and molars. In addition, clinical and radiographic findings of these VRF-affected teeth were retrospectively evaluated. Thirty extracted teeth with a clinically diagnosed VRF were embedded in methylmethacrylate. Serial ground sections (perpendicular to the longitudinal axis of the root) were stained with toluidine blue and basic fuchsin. The specimens were photographed and assessed with regard to the vertical and horizontal extent as well as to the course of the VRF. Most VRFs ran from the cervical to the apical region (81.3%). In the axial plane, 50% of VRFs traversed the root completely from buccal to oral. Another 40.6% of VRFs were limited to the buccal root portion. 84.4% of the evaluated roots presented an isthmus. Overall, the VRF was associated with the isthmus in 56.3%, but bypassed the isthmus in 28.1%. The most frequently observed clinical findings included pain (in 60% of the evaluated cases), presence of a fistula (46.7%) and an isolated periodontal pocket with ≥6 mm probing depth (40%). A periapical radiolucency (53.3%) was the most frequent radiographic finding in VRFs. “J-shape” lesions were seen in eight cases (26.7%).