Monise de Paula Rodrigues1, Priscilla Barbosa Ferreira Soares2, Andréa Dollores Correia Miranda Valdivia1, Roberto Sales Pessoa1, Crisnicaw Veríssimo3, Antheunis Versluis4, Carlos José Soares5. 1. Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Minas Gerais, Brazil. 2. Department of Periodontology and Implantology, School of Dentistry, Federal University of Uberlândia, Minas Gerais, Brazil. 3. School of Dentistry, University of Uberaba, Minas Gerais, Brazil. 4. Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee. 5. Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Minas Gerais, Brazil. Electronic address: carlosjsoares@ufu.br.
Abstract
INTRODUCTION: A ferrule on anterior endodontic-treated teeth has been evaluated using clinical trials, in vitro tests, and finite element analysis (FEA). The patient-specific FEA with a nonuniform ferrule and nonlinear contact biting load associated with clinical validation can be used to predict failure. METHODS: A patient was selected with both maxillary central incisors with different ferrule designs who received endodontic treatment and restoration using a fiber post, composite core, and computer aided design and computer aided manufacturing lithium disilicate ceramic crowns. Strain gauges were attached to the buccal surfaces of both teeth to record ceramic strain during bite force recording for FEA validation. Cone-beam computed tomographic imaging was performed, and the Digital Imaging and Communication in Medicine files were exported to Mimics, 3-Matic (Materialise, Leuven, Belgium) and Patran (MSC Software, Santa Ana, CA) software to create a patient-specific FEA model. Bite load was applied using contact load applied by antagonist teeth (155 N). Mechanical properties were obtained from the literature. Modified von Mises equivalent stress was used for stress evaluation. RESULTS: Stresses on the dentin and fiber post on the left incisor, which had a nonuniform ferrule, were higher compared with the right incisor. The strain values recorded for the right central incisor (strain gauge =79.9 ± 3.8 μS and FEA = 69.5 μS) and the left central incisor (strain gauge = 83.5 ± 5.3 μS and FEA = 73.9 μS) validate the FEA analysis. CONCLUSIONS: FEA was validated with in vivo strain values measured at the buccal crown surfaces, supporting that the stress levels were realistic for investigation of the clinical performance of fiber posts. Maintaining a uniform ferrule was more favorable than a localized higher ferrule.
INTRODUCTION: A ferrule on anterior endodontic-treated teeth has been evaluated using clinical trials, in vitro tests, and finite element analysis (FEA). The patient-specific FEA with a nonuniform ferrule and nonlinear contact biting load associated with clinical validation can be used to predict failure. METHODS: A patient was selected with both maxillary central incisors with different ferrule designs who received endodontic treatment and restoration using a fiber post, composite core, and computer aided design and computer aided manufacturing lithium disilicate ceramic crowns. Strain gauges were attached to the buccal surfaces of both teeth to record ceramic strain during bite force recording for FEA validation. Cone-beam computed tomographic imaging was performed, and the Digital Imaging and Communication in Medicine files were exported to Mimics, 3-Matic (Materialise, Leuven, Belgium) and Patran (MSC Software, Santa Ana, CA) software to create a patient-specific FEA model. Bite load was applied using contact load applied by antagonist teeth (155 N). Mechanical properties were obtained from the literature. Modified von Mises equivalent stress was used for stress evaluation. RESULTS: Stresses on the dentin and fiber post on the left incisor, which had a nonuniform ferrule, were higher compared with the right incisor. The strain values recorded for the right central incisor (strain gauge =79.9 ± 3.8 μS and FEA = 69.5 μS) and the left central incisor (strain gauge = 83.5 ± 5.3 μS and FEA = 73.9 μS) validate the FEA analysis. CONCLUSIONS: FEA was validated with in vivo strain values measured at the buccal crown surfaces, supporting that the stress levels were realistic for investigation of the clinical performance of fiber posts. Maintaining a uniform ferrule was more favorable than a localized higher ferrule.