The objective of this study was to determine the in vitro corrosion products that resulted from crevice corrosion of low-and high-copper dental amalgams. Specimens were potentiostatically polarized in a chloride-containing electrolyte while set against a PTFE surface to form a crevice. After 16 h, corrosion products were examined by light microscopy, SEM, EDS, and XRD. Analysis showed the presence of three previously reported products [Sn4(OH)6Cl2, SnO, and Cu2O] and a new product, CuCl, which formed on high-copper, γ2-free amalgams. Thermodynamic considerations show that CuCI is stable for the reported in vivo potentials of amalgam restorations and the high acidity and high chloride ion concentration associated with crevice corrosion.
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References
1.
Brune, D. (1981): Corrosion of Amalgams, Scand J Dent Res89 :506-514.
2.
Finkelstein, G.F. and Greener, E.H. (1978): Role of Mucin and Albumin in Saline Polarization of Dental Amalgam, J Oral Rehabil5:95-100.
3.
Guthrow, C.E.; Johnson, L.B.; and Lawless, K.R. (1967): Corrosion of Dental Amalgam and Its Component Phases, J Dent Res46:1372-1381.
4.
Hoar, T.P. (1937): The Corrosion of Tin in Nearly Neutral Solutions , Trans Faraday Soc33:1152-1167.
5.
Katan, T. and Ryge, G. (1979): Corrosion Penetration in Crevices of Dental Amalgam , J Electrochem Soc126:903-908.
6.
Leirskar, J. (1974): On the Mechanism of Cytotoxicity of Silver and Copper Amalgams in a Cell Culture System, Scand J Dent Res82:74-81.
7.
Lin, J.-H.C.; Marshall, G.W.; and Marshall, S.J. (1983a): Microstructures of Cu-rich Amalgams after Corrosion , J Dent Res62:112-115.
8.
Lin, J.-H.C.; Marshall, G.W.; and Marshall, S.J. (1983b): Corrosion Product Formation Sequence on Cu-rich Amalgams in Various Solutions, J Biomed Mater Res17:913-920.
9.
Marek, M. (1983): The Corrosion of Dental Materials. In: Treatise on Materials Science and Technology, Vol. 23, J.C. Scully, Ed., London: Academic Press, pp. 331-394.
10.
Marek, M. and Hochman, R.F. (1974): A Simulated Crevice Corrosion Experiment for pH and Solution Chemistry Determinations, Corrosion30:208-210.
11.
Marek, M. and Hochman, R.F. (1975): Mechanism of Crevice Corrosion of Dental Amalgam , IADR Prog & Abst 54: No. L166.
12.
Marek, M.; Hochman, R.F.; and Butler, M.F. (1973): Crevice Corrosion in Dental Amalgam Restorations , IADR Prog & Abst 52: No. 194.
13.
Marek, M.; Okabe, T.; Butts, M.B.; and Fairhurst, C.W. (1983): Corrosion of the η'(Cu-Sn) Phase in Dental Amalgam, J Biomed Mater Res17:921-929.
14.
Marshall, G.W., Jr. ; Marshall, S.J.; Letzel, H.; and Vrijhoef, M.M.A. (1987): Microstructures of Cu-rich Amalgam Restorations with Moderate Clinical Deterioration, Dent Mater3:135-143.
15.
Marshall, S.J.; Lin, J.-H.C.; and Marshall, G.W., Jr. (1982): Cu2O and CuCl2-3Cu(OH)2 Corrosion Products on Copper Rich Dental Amalgams, J Biomed Mater Res16:81-85.
16.
Marshall, S.J. and Marshall, G.W., Jr. (1980): Sn4(OH)6Cl2 and SnO Corrosion Products of Amalgams, J Dent Res59 :820-823.
17.
Mateer, R.S. and Reitz, C.D. (1970): Corrosion of Amalgam Restorations, J Dent Res49:399-407.
18.
May, R. (1953): Some Observations on the Mechanism of Pitting Corrosion, J Inst Metals32:65-74.
19.
Moberg, L.-E.; Appelgren, B.; and Sjostrand, N.O. (1985): Effects of Cupric Ions on Isolated Guinea-pig Ileum, Acta Odontol Scand43:223-229.
20.
Nilner, K. and Holland, R.I. (1985): Electrochemical Potentials of Amalgam Restorations in vivo, Scand J Dent Res93 :357-359.
21.
Otani, H.; Jesser, W.A.; and Wilsdorf, H.G.F. (1973): The in vivo and in vitro Corrosion Products of Dental Amalgams, J Biomed Mater Res7:523-539.
22.
Pass, G. and Sutcliffe, H. (1974): Practical Inorganic Chemistry, 2nd ed., London: Chapman and Hall , p. 76.
23.
Pourbaix, M. (1976): Some Applications of Potential-pH Diagrams to the Study of Localized Corrosion, J Electrochem Soc123:25C-36C.
24.
Powder Diffraction File (1977): Joint Committee on Powder Diffraction Standards, International Centre for Diffraction Data, Swarthmore, Pennsylvania.
25.
Sarkar, N.K. (1978): Creep, Corrosion and Marginal Fracture of Dental Amalgams, J Oral Rehabil5:413-423.
26.
Sarkar, N.K. and Greener, E.H. (1975): Electrochemistry of the Saline Corrosion of Conventional Dental Amalgams, J Oral Rehabil2:49-62.
27.
Sarkar, N.K.; Leonard, R.; Fuys, R.A., Jr.; and Stan-Ford, J.W. (1976): Surface and Interface Corrosion of Dental Amalgams , IADR Prog & Abst 55: No. 892.
28.
Sutow, E.J.; Jones, D.W.; Hall, G.C.; Usher, G.; and Milne, E.L. (1982): In vitro Corrosion Evaluation of Dental Amalgam , IADR Prog & Abst 61: No. 632.
29.
Sutow, E.J.; Jones, D.W.; and Hall, G.C. (1989): Correlation of Dental Amalgam Crevice Corrosion with Clinical Ratings, J Dent Res68:82-88.
30.
Van Muylder, J.; De Zoubov, N.; and Pourbaix, M. (1961): Diagrammes D'Equilibres Tension - pH des Systemes Cu-H2O et Cu-Cl-H2O a 25°C, Report No. 755, CEBELCOR, Brussels, Belgium, pp. 1-23.
31.
Weast, R.C. (1979): Handbook of Chemistry and Physics, 60th ed., Cleveland: CRC Press, pp. 8-76.
