Document Detail


Virtual prototyping of adhesively restored, endodontically treated molars.
MedLine Citation:
PMID:  20493323     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
STATEMENT OF PROBLEM: Teeth and dental restorations are difficult to model because of their complex anatomical shape and layered structure. PURPOSE: The purpose of this investigation was to describe the use of an efficient virtual prototyping method for the comparison of bonded porcelain and composite resin onlays to restore endodontically treated molars. MATERIAL AND METHODS: An intact mandibular molar was digitized with a micro-CT scanner. Surface contours of enamel and dentin were fitted following tooth segmentation based on pixel density using an interactive medical image processing software (Mimics). Standard triangle language files of enamel and dentin surfaces were then exported to a design and meshing software (3-matic). The root filling, base material, and a 3.0-mm-thick onlay were created by merging primitive shapes. Surface splitting, removal of unwanted surfaces, and remeshing allowed generation of an assembly with optimized interfacial mesh congruence and T-junctions. Solid 3-dimensional (3-D) models obtained in a finite element software (Marc/Mentat) were subjected to nonlinear contact analysis to simulate occlusal loading at 200 N and 700 N. Maximum principal stress values were used to calculate the risk of fracture and for validation with existing experimental data. RESULTS: There were similar stress distributions at 200 N (maximum peak values of 24 to 26 MPa) for both restorative materials, but marked differences at 700 N, with the porcelain onlay showing occlusal stress peaks more than 30% higher than composite resin. High stress concentrations were found at 700 N at the root level of the porcelain-restored tooth (95 MPa). For the composite resin onlay, secondary peaks of stress at the 700-N load were found above the cemento-enamel junction (47 MPa) with only minor effects at the root. The risk of fracture was increased for porcelain onlays, which correlated with the existing validation data and the decreased risk of fracture below the cemento-enamel junction (CEJ) observed for composite resin onlays. CONCLUSIONS: The virtual prototyping method can generate detailed and valid 3-D finite element models of a restored, endodontically treated molar. The decreased risk of fracture and more favorable stress distribution of adhesive composite resin onlays compared to porcelain onlays were confirmed. This method is efficient and may be used for other medical and dental applications.
Authors:
Pascal Magne
Related Documents :
523513 - An articulatory experiment on voice onset time in german stop consonants.
8280313 - An isoelastic prosthesis using a new composite material.
8830973 - Effects of alkaline phosphatase on bone healing around plasma-sprayed titanium implants...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of prosthetic dentistry     Volume:  103     ISSN:  1097-6841     ISO Abbreviation:  J Prosthet Dent     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-05-24     Completed Date:  2010-08-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0376364     Medline TA:  J Prosthet Dent     Country:  United States    
Other Details:
Languages:  eng     Pagination:  343-51     Citation Subset:  D; IM    
Copyright Information:
Copyright 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.
Affiliation:
University of Southern California, Herman Ostrow School of Dentistry, Los Angeles, CA, USA. magne@usc.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Bite Force
Composite Resins
Computer Simulation*
Dental Bonding*
Dental Models
Dental Porcelain
Dental Stress Analysis / methods*
Elastic Modulus
Finite Element Analysis
Humans
Inlays*
Mandible
Molar
Tooth, Nonvital / radiography,  rehabilitation*
User-Computer Interface*
X-Ray Microtomography
Chemical
Reg. No./Substance:
0/Composite Resins; 12001-21-7/Dental Porcelain

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Accuracy of CAD/CAM-guided surgical template implant surgery on human cadavers: Part I.
Next Document:  The effect of acid etchant type and dentin location on tubular density and dimension.