Design features of a three-dimensional molar crown and related maximum principal stress. A finite element model study

Brian T. Rafferty, Malvin N. Janal, Ricardo A. Zavanelli, Nelson R F A Silva, E. Dianne Rekow, Van P. Thompson, Paulo Coelho

Research output: Contribution to journalArticle

Abstract

Objective: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. Methods: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. Results: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. Conclusion: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters.

Original languageEnglish (US)
Pages (from-to)156-163
Number of pages8
JournalDental Materials
Volume26
Issue number2
DOIs
StatePublished - Feb 2010

Fingerprint

Tooth Preparation
Crowns
Cements
Tooth Crown
Veneers
Ceramics
Analysis of Variance
Tooth
Software
Loads (forces)
Structural ceramics
Analysis of variance (ANOVA)
Stress concentration
Computer aided design

Keywords

  • All-ceramic
  • Crowns
  • Factorial analysis
  • Finite element analysis

ASJC Scopus subject areas

  • Dentistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Medicine(all)

Cite this

Design features of a three-dimensional molar crown and related maximum principal stress. A finite element model study. / Rafferty, Brian T.; Janal, Malvin N.; Zavanelli, Ricardo A.; Silva, Nelson R F A; Rekow, E. Dianne; Thompson, Van P.; Coelho, Paulo.

In: Dental Materials, Vol. 26, No. 2, 02.2010, p. 156-163.

Research output: Contribution to journalArticle

Rafferty, Brian T. ; Janal, Malvin N. ; Zavanelli, Ricardo A. ; Silva, Nelson R F A ; Rekow, E. Dianne ; Thompson, Van P. ; Coelho, Paulo. / Design features of a three-dimensional molar crown and related maximum principal stress. A finite element model study. In: Dental Materials. 2010 ; Vol. 26, No. 2. pp. 156-163.
@article{3cf947fd8656424385d4deb4c1e69e42,
title = "Design features of a three-dimensional molar crown and related maximum principal stress. A finite element model study",
abstract = "Objective: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. Methods: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. Results: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. Conclusion: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters.",
keywords = "All-ceramic, Crowns, Factorial analysis, Finite element analysis",
author = "Rafferty, {Brian T.} and Janal, {Malvin N.} and Zavanelli, {Ricardo A.} and Silva, {Nelson R F A} and Rekow, {E. Dianne} and Thompson, {Van P.} and Paulo Coelho",
year = "2010",
month = "2",
doi = "10.1016/j.dental.2009.09.009",
language = "English (US)",
volume = "26",
pages = "156--163",
journal = "Dental Materials",
issn = "0109-5641",
publisher = "Elsevier Science",
number = "2",

}

TY - JOUR

T1 - Design features of a three-dimensional molar crown and related maximum principal stress. A finite element model study

AU - Rafferty, Brian T.

AU - Janal, Malvin N.

AU - Zavanelli, Ricardo A.

AU - Silva, Nelson R F A

AU - Rekow, E. Dianne

AU - Thompson, Van P.

AU - Coelho, Paulo

PY - 2010/2

Y1 - 2010/2

N2 - Objective: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. Methods: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. Results: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. Conclusion: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters.

AB - Objective: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. Methods: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. Results: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. Conclusion: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters.

KW - All-ceramic

KW - Crowns

KW - Factorial analysis

KW - Finite element analysis

UR - http://www.scopus.com/inward/record.url?scp=75049086035&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=75049086035&partnerID=8YFLogxK

U2 - 10.1016/j.dental.2009.09.009

DO - 10.1016/j.dental.2009.09.009

M3 - Article

C2 - 19857888

AN - SCOPUS:75049086035

VL - 26

SP - 156

EP - 163

JO - Dental Materials

JF - Dental Materials

SN - 0109-5641

IS - 2

ER -