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Microstructure, phase content, and thermal stability of a cast Co–Cr dental alloy after porcelain sintering cycles using electron backscatter diffraction

Published online by Cambridge University Press:  30 June 2015

Kai Chun Li*
Affiliation:
Sir John Walsh Research Institute, University of Otago, Dunedin 9054, New Zealand
David J. Prior
Affiliation:
Department of Geology, University of Otago, Dunedin 9054, New Zealand
J. Neil Waddell
Affiliation:
Sir John Walsh Research Institute, University of Otago, Dunedin 9054, New Zealand
Michael V. Swain
Affiliation:
Biomaterials Laboratory, Faculty of Dentistry, University of Sydney, Sydney, Australia
*
a)Address all correspondence to this author. e-mail: lika6144@gmail.com
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Abstract

Phase maps of Co–Cr alloys bonded to dental porcelain cycled through an incremental number of porcelain firings at two separate thicknesses (0.5 and 1 mm) were analyzed. Bulk hexagonal close-packed (hcp) phase vol% of the alloy was found to increase with the number of porcelain firings for both 0.5 and 1 mm specimens. At the metal-porcelain interface, a uniform fine-grained hcp phase was observed. The depth and grain size of this hcp layer increased with the number of porcelain firings with the thicker specimens undergoing more substantial growth and transformation. Simple heat transfer modeling of the specimens during heat treatment cycles indicated that the thicker specimen had more time at high temperature to affect the face-centered cubic to hcp phase transformation. Therefore, the amount of porcelain firings and the thickness of the alloy should be considered and kept to a minimal when manufacturing metal-porcelain restoration.

Type
Articles
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Buford, A. and Goswami, T.: Review of wear mechanisms in hip implants: Paper I – General. Mater. Des. 25(5), 385393 (2004).CrossRefGoogle Scholar
Pjetursson, B.E., Sailer, I., Zwahlen, M., and Hammerle, C.H.: A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of at least 3 years. Part I: Single crowns. Clin. Oral Implants Res. 18(Suppl. 3), 7385 (2007).Google Scholar
Sailer, I., Pjetursson, B.E., Zwahlen, M., and Hammerle, C.H.: A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of at least 3 years. Part II: Fixed dental prostheses. Clin. Oral Implants Res. 18(Suppl. 3), 8696 (2007).Google Scholar
Reitemeier, B., Hansel, K., Kastner, C., and Walter, M.H.: Metal-ceramic failure in noble metal crowns: 7-Year results of a prospective clinical trial in private practices. Int. J. Prosthodont 19(4), 397399 (2006).Google Scholar
Walton, T.R. and O'Brien, W.J.: Thermal stress failure of porcelain bonded to a palladium-silver alloy. J. Dent. Res. 64(3), 476480 (1985).Google Scholar
Lenz, J. and Kessel, S.: Thermal stresses in metal–ceramic specimens for the ISO crack initiation test (three-point flexure bond test). Dent. Mater. 14(4), 277280 (1998).Google Scholar
Ishida, K. and Nishizawa, T.: The Co-Cr (Cobalt-Chromium) system. Bull. Alloy Phase Diagrams 11(4), 357370 (1990).Google Scholar
Oikawa, K., Qin, G-W., Ikeshoji, T., Kainuma, R., and Ishida, K.: Direct evidence of magnetically induced phase separation in the fcc phase and thermodynamic calculations of phase equilibria of the Co–Cr system. Acta Mater. 50(9), 22232232 (2002).Google Scholar
Okamoto, H.: Co-Cr (cobalt-chromium). J. Phase Equilib. 24(4), 377378 (2003).Google Scholar
Anusavice, K.J., Ringle, R.D., and Fairhurst, C.W.: Adherence controlling elements in ceramic-metal systems. II. Nonprecious alloys. J. Dent. Res. 56(9), 10531061 (1977).Google Scholar
López, H.F. and Saldivar-Garcia, A.J.: Martensitic transformation in a cast Co-Cr-Mo-C alloy. Metall. Mater. Trans. A 39(1), 818 (2008).CrossRefGoogle Scholar
Turrubiates-Estrada, R., Salinas-Rodriguez, A., and Lopez, H.F.: FCC to HCP transformation kinetics in a Co–27Cr–5Mo–0.23C alloy. J. Mater. Sci. 46(1), 254262 (2011).Google Scholar
Matković, T., Matković, P., and Malina, J.: Effects of Ni and Mo on the microstructure and some other properties of Co–Cr dental alloys. J. Alloys Compd. 366(1–2), 293297 (2004).Google Scholar
Lee, S-H., Nomura, N., and Chiba, A.: Significant improvement in mechanical properties of biomedical Co-Cr-Mo alloys with combination of N addition and Cr-enrichment. Mater. Trans. 49(2), 260264 (2008).Google Scholar
Prior, D., Mariani, E., and Wheeler, J.: EBSD in the earth sciences: Applications, common practice, and challenges. In Electron Backscatter Diffraction in Materials Science, Schwartz, A.J., Kumar, M., Adams, B.L., Field, D.P. eds., Springer, 2009.Google Scholar
Shigematsu, N., Prior, D.J., and Wheeler, J.: First combined electron backscatter diffraction and transmission electron microscopy study of grain boundary structure of deformed quartzite. J. Microsc. 224(Pt 3), 306321 (2006).Google Scholar
Vollmer, M.: Newton's law of cooling revisited. Eur. Phys. J. 30(5), 1063 (2009).CrossRefGoogle Scholar
Kingery, W.D.: Introduction to Ceramics (Wiley, 1960).Google Scholar
Levesque, L.: Law of cooling, heat conduction and Stefan-Boltzmann radiation laws fitted to experimental data for bones irradiated by CO2 laser. Biomed. Opt. Express 5(3), 701712 (2014).Google Scholar
Karato, S.: Deformation of Earth Materials: An Introduction to the Rheology of Solid Earth (Cambridge University Press, 2008).Google Scholar
Tullis, J. and Yund, R.A.: Grain growth kinetics of quartz and calcite aggregates. J. Geol. 90(3), 301318 (1982).Google Scholar
Nishiyama, Z.: Martensitic Transformation (Elsevier Science, 2012).Google Scholar
Yamanaka, K., Mori, M., and Chiba, A.: Effects of nitrogen addition on microstructure and mechanical behavior of biomedical Co–Cr–Mo alloys. J. Mech. Behav. Biomed. Mater. 29(0), 417426 (2014).Google Scholar
Seward, G.G.E., Celotto, S., Prior, D.J., Wheeler, J., and Pond, R.C.: In situ SEM-EBSD observations of the hcp to bcc phase transformation in commercially pure titanium. Acta Mater. 52(4), 821832 (2004).Google Scholar
Lautenschlager, E.P., Greener, E.H., and Elkington, W.E.: Microprobe analyses of gold-porcelain bonding. J. Dent. Res. 48(6), 12061210 (1969).CrossRefGoogle ScholarPubMed