This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Anusavice, K.J. Articles by Hojjatie, B. Search for Related Content PubMed PubMed Citation Articles by Anusavice, K.J. Articles by Hojjatie, B. Pubmed/NCBI databases Substance via MeSH Social Bookmarking                         What's this?

Stress Distribution in Metal-Ceramic Crowns with a Facial Porcelain Margin

Department of Dental Biomaterials, College of Dentistry, University of Florida, Gainesville, Florida 32610

B. Hojjatie

Department of Dental Biomaterials, College of Dentistry, University of Florida, Gainesville, Florida 32610

The use of metal-ceramic restorations with porcelain butt-joint facial margins has increased in the past several years. Although these crowns exhibit improved esthetics compared with metal-ceramic crowns which display a metal gingival collar or metal knife-edge margin, the effectiveness of this design in resisting intra-oral forces is not known. The objective of this study was to analyze the stress distribution induced by simulated intra-oral loads on crowns with variable coping configurations. The copings, with a thickness of either 0. 1 or 0.3 mm, were modeled with a facial termination of metal at three locations: at the gingival floor, 0.9 mm above the gingival floor, and 4.2 mm above the gingival floor. The coping and crown dimensions were based on a prepared maxillary central incisor with a facial shoulder and a lingual chamfer. Both Ni-Cr and Au-Pd alloy copings were employed in the crown models. Finite element stress analyses were performed on crowns which were subjected to several loading conditions. A cement film thickness of 0.030 mm was assumed.

For all cases, the stresses which developed in porcelain and cement near the facial and lingual margins due to a vertical load of 200 N were predominately compressive in nature. For the crowns with Ni-Cr copings, the tensile stress in porcelain ranged from 11.0 MPa (for crowns with a facial metal thickness of 0.3 mm) to 12.5 MPa (for a metal thickness of 0.1 mm). The corresponding stresses for crowns with Au-Pd alloy copings were 8.3 MPa and 8.6 MPa, respectively. Maximum compressive stresses in cement near the lingual margin were 22.3 MPa for the Ni-Cr crowns and 30.0 MPa for the Au-Pd crowns. The maximum tensile stress in porcelain was 29.0 MPa and occurred near the area of loading for the Au-Pd case. The maximum tensile stress in the facial porcelain region (8.3 MPa) developed within the incisal third of the facial surface. Under the conditions assumed in this study, the alloy type, coping thickness, and coping termination point have a negligibly small effect on the stresses induced in porcelain or cement near the facial margin.

REFERENCES

• Anusavice, K.J.; Hojjatie, B.; and Dehoff, P.H. (1986): Influence of Metal Thickness on Stress Distribution in Metal-Ceramic Crowns. J Dent Res 65:1173-1178.[Abstract/Free Full Text]
• Bathe, K.J.; Wilson, E.L.; and Peterson, F.E. (1974): SAP IV, A Structural Analysis Program for Static and Dynamic Response of Linear Systems, Report No. EERG 73-11, Berkeley, CA: College of Engineering, University of California.
• Behrend, D.A. (1982): Ceramometal Restorations with Supragingival Margins, J Prosthet Dent 47:625-632.[Medline] [Order article via Infotrieve]
• Brecker, S. (1956): Porcelain Baked to Gold, J Prosthet Dent 6:801-810.[Medline] [Order article via Infotrieve]
• Choung, C.K.; Garlapo, G.A.; Brown, M.H.; and Soren-Sen, S.E. (1982): Procedure for a Simplified Collarless Metal-Ceramic Restoration Using Gold Powder, J Prosthet Dent 47:449-453.[Medline] [Order article via Infotrieve]
• Christensen, G.J.; Brown, T.A.; and Babb, R. (1969): Accuracy of Fit of Direct-firing Porcelain Inlays, J Prosthet Dent 22:46-53.[Medline] [Order article via Infotrieve]
• Crose, J.G. and Jones, R.M. (1971): SAAS III, Finite Element Stress Analysis of Axisymmetric and Plane Solids with Different Orthotropic, Temperature Dependent Materials Properties in Tension and Compression. San Bernardino, CA: Aerospace Corporation.
• Farah, J.W. and Craig, R.G. (1975): Distribution of Stresses in Porcelain-Fused-to-Metal and Porcelain Jacket Crowns, J Dent Res 54:255-261.[Medline] [Order article via Infotrieve]
• Goodacre, C.J.; Van Roekel, N.B.; Dykema, R.W.; and Ullman, R.B. (1977): The Collarless Metal-Ceramic Crown, J Prosthet Dent 38:615-622.[Medline] [Order article via Infotrieve]
• Microtab (1985): A General Purpose Finite Element Model Generator for the IBM-PC and Compatible Micro-computers, User's Manual, Austin, TX: Structural Analysis, Inc.
• Prince, J.; Donovan, T.E.; and Presswood, R.G. (1983): The All-porcelain Labial Margin for Ceramometal Restorations: A New Concept, J Prosthet Dent 50:793-796.[Medline] [Order article via Infotrieve]
• SAP86^TM (1985): A Finite Element Program for Static and Dynamic Analysis of Linear Structural Systems, Installation and User's Manual, Release 2.0, San Francisco, CA: Number Cruncher Microsystems, Inc.
• Schneider, D.M.; Levi, M.S.; and Mori, D.F. (1976): Porcelain Shoulder Adaptation Using Direct Refractory Dies, J Prosthet Dent 36:583-587.[Medline] [Order article via Infotrieve]
• Sozio, R.B. and Riley, E.J. (1977): A Precision Ceramic-Metal Restoration with a Facial Butted Margin, J Prosthet Dent 37:517-521.[Medline] [Order article via Infotrieve]
• Wheeler, R.C. (1965): A Textbook of Dental Anatomy and Physiology, 4th ed. Philadelphia: W.B. Saunders Company, p. 22.

Journal of Dental Research, Vol. 66, No. 9, 1493-1498 (1987)
DOI: 10.1177/00220345870660091601


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				T.W.P. Korioth and A. Versluis Modeling the Mechanical Behavior of the Jaws and Their Related Structures By Finite Element (Fe) Analysis Critical Reviews in Oral Biology & Medicine, January 1, 1997; 8(1): 90 - 104. [Abstract] [Full Text] [PDF]

				S. Ban and K.J. Anusavice Influence of Test Method on Failure Stress of Brittle Dental Materials Journal of Dental Research, December 1, 1990; 69(12): 1791 - 1799. [Abstract] [PDF]

				P.H. Dehoff and K.J. Anusavice Effect of Visco-elastic Behavior on Stress Development in a Metal-Ceramic System Journal of Dental Research, August 1, 1989; 68(8): 1223 - 1230. [Abstract] [PDF]

				K.J. Anusavice and B. Hojjatie Influence of Incisal Length of Ceramic and Loading Orientation on Stress Distribution in Ceramic Crowns Journal of Dental Research, November 1, 1988; 67(11): 1371 - 1375. [Abstract] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Anusavice, K.J. Articles by Hojjatie, B. Search for Related Content PubMed PubMed Citation Articles by Anusavice, K.J. Articles by Hojjatie, B. Pubmed/NCBI databases Substance via MeSH Social Bookmarking                         What's this?