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Influence of Crown Ferrule Heights and Dowel Material Selection on the Mechanical Behavior of Root‐Filled Teeth: A Finite Element Analysis
Author(s) -
Watanabe Mauricio U.,
Anchieta Rodolfo Bruniera,
Rocha Eduardo Passos,
Kina Sidney,
Almeida Erika Oliveira de,
Junior Amilcar Chagas Freitas,
Basting Roberta Tarkany
Publication year - 2012
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2011.00832.x
Subject(s) - ferrule , dowel , materials science , crown (dentistry) , maxillary central incisor , composite material , von mises yield criterion , dentin , orthodontics , finite element method , structural engineering , medicine , optics , engineering , physics , optical fiber
Purpose: This study used the 3D finite element (FE) method to evaluate the mechanical behavior of a maxillary central incisor with three types of dowels with variable heights of the remaining crown structure, namely 0, 1, and 2 mm. Materials and Methods: Based on computed microtomography, nine models of a maxillary central incisor restored with complete ceramic crowns were obtained, with three ferrule heights (0, 1, and 2 mm) and three types of dowels (glass fiber = GFD; nickel‐chromium = NiCr; gold alloy = Au), as follows: GFD0 – restored with GFD with absence (0 mm) of ferrule; GFD1 – similar, with 1 mm ferrule; GFD2 – glass fiber with 2 mm ferrule; NiCr0 – restored with NiCr alloy dowel with absence (0 mm) of ferrule; NiCr1 – similar, with 1 mm ferrule; NiCr2 – similar, with 2 mm ferrule; Au0 – restored with Au alloy dowel with absence (0 mm) of ferrule; Au1 – similar, with 1 mm ferrule; Au2 – similar, with 2 mm ferrule. A 180 N distributed load was applied to the lingual aspect of the tooth, at 45° to the tooth long axis. The surface of the periodontal ligament was fixed in the three axes (x = y = z = 0). The maximum principal stress (σ max ), minimum principal stress (σ min ), equivalent von Mises (σ vM ) stress, and shear stress (σ shear ) were calculated for the remaining crown dentin, root dentin, and dowels using the FE software. Results: The σ max (MPa) in the crown dentin were: GFD0 = 117; NiCr0 = 30; Au0 = 64; GFD1 = 113; NiCr1 = 102; Au1 = 84; GFD2 = 102; NiCr2 = 260; Au2 = 266. The σ max (MPa) in the root dentin were: GFD0 = 159; NiCr0 = 151; Au0 = 158; GFD1 = 92; NiCr1 = 60; Au1 = 67; GFD2 = 97; NiCr2 = 87; Au2 = 109. Conclusion: The maximum stress was found for the NiCr dowel, followed by the Au dowel and GFD; teeth without ferrule are more susceptible to the occurrence of fractures in the apical root third.