FAILURE MECHANICS OF AN ENDODONTICALLY TREATED MAXILLARY FIRST PREMOLAR: A NUMERICAL ANALYSIS
Veronika Fedotova1; Estevam Barbosa de las Casas1; Osvaldo L. Manzoli2; Claudia M. A. Mattos3; Eduardo A. Rodriguez2
1 Department of Structural Engineering, Universidade Federal de Minas Gerais, Belo Horizonte; 2 Department of Civil Engineering, UNESP - São Paulo State University, Bauru; 3 Department of Dental Prosthodontics, Universidade Federal do Espirito Santo, Vitoria
doi:10.20906/CPS/CILAMCE2017-1048
Resumo
The restoration of endodontically treated teeth is a widely studied, yet controversial topic in dentistry. Questions remain about the materials and clinical procedures to be applied in restoration of these teeth, as irreparable fracture is one of the most common causes of tooth loss after endodontic treatment. When a coronal structure of a tooth is missing, a post-and-core restoration system is necessary to retain the prosthetic crown. Although some researchers believed in the past that posts could improve the fracture resistance in endodontically treated tooth, there are reports arguing that preparation of a post space may increase the chances of root fracture. According to some studies, the catastrophic vertical root fractures are most common in premolars or other teeth with narrow roots, and the fracture pivots from the apical end of a post. Provision of a full coverage crown is reported to increase the resistance of posterior teeth to fracture, and is recommended particularly in molars and maxillary premolars. Other clinically observed failure modes of post-and-core restoration system are post fracture or post dislodgement, as the occlusal stresses are transferred directly to the core and post. The present study aims to investigate the mechanics of failure of endodontically treated maxillary first premolar tooth restored by post-and-core and complete crown system. The study is done using finite element method employing the strategy named mesh fragmentation technique, as proposed by Manzoli et al. This technique is based on the use of interface solid finite elements with a high aspect ratio, allowing along with an appropriate continuum damage model a simulation of complex crack patterns without the need of crack path tracking algorithms. A three-dimensional CAD model of the tooth is adapted from a previously constructed model based on computed tomography images. The model consists of a complete ceramic crown, dentin with composite resin core restoration, glass fibre post cemented into the palatal root canal
Palavras-chave: Finite Element Method; Premolar Tooth; Endodontic Treatment; Post-and-core; Root Fracture; Damage Model; Interface Finite Elements