Vertical root fractures in root canal-treated teeth

Vertical root fractures (VRF) are longitudinally orientated, complete or incomplete cracks that can occur on the tooth root at any level and usually initiate from the internal root canal wall. VRFs commonly occur in root canal-filled teeth and may result in the loss of the affected tooth. A PubMed search to April 2017 was completed using the key words "vertical root fractures", "endodontic treatment" and "root-filled teeth". Abstracts were read to identify relevant articles before retrieval. A search of reference lists identified further studies and 62 articles were selected. Diagnosis of VRFs can often be challenging. The combined use of history taking, periodontal probing and periapical radiographs is essential. The aetiology is multifaceted and includes predisposing factors such as tooth type, root canal morphology, and iatrogenic factors involving materials and devices used in root canal treatment and for post space preparation. Emerging risk factors such as implant-associated VRF have recently been identified. Prevention of VRF includes conservation of dentine during root canal instrumentation, appropriate choices of materials for preparation, irrigation and disinfection and avoiding excessive forces during lateral and vertical condensation of gutta-percha (GP). Cracks formed during root-end preparations in apical surgery may also lead to VRF, and teeth with the "butterfly effect" seem to be more at risk. Traditionally, treatment of VRFs has been tooth extraction. Alternative treatments such as bonding of separated root fragments followed by intentional replantation have gained some momentum. Parole chiave: cracks, root canal filling, vertical root fracture