Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data.
OBJECTIVE
The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis.


METHODS
Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σ(max)) values were evaluated for the root dentin, cement layer, and glass fiber post.


RESULTS
The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa).


CONCLUSIONS
The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root.
Univ. Estadual Paulista, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, AraçatubaSP, Brazil.
Priscilla Cardoso
PC
Lazari
São Leopoldo Mandic, CampinasSP, Brazil.
Rodrigo Caldeira Nunes de
RC
Oliveira
Univ. Estadual Paulista, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, AraçatubaSP, Brazil.
Rodolfo Bruniera
RB
Anchieta
Univ. Estadual Paulista, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, AraçatubaSP, Brazil.
Erika Oliveira de
EO
Almeida
Potiguar University, School of Health Sciences, NatalRN, Brazil.
Amilcar Chagas
AC
Freitas Junior
Univ. Estadual Paulista, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, AraçatubaSP, Brazil.
Sidney
S
Kina
Univ. Estadual Paulista, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, AraçatubaSP, Brazil.
Eduardo Passos
EP
Rocha
D003738:Dental Cements / Q000737:chemistry*; D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D003804:Dentin; D055119:Elastic Modulus; D020342:Finite Element Analysis; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D003765:Models, Dental; D011176:Post and Core Technique; D012016:Reference Values; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D055114:X-Ray Microtomography
D003738:Dental Cements; C009753:fiberglass