The potential of copper alloy as alternative material for post and core applications.

Abstract

Objective: The purpose of this study was to investigate the use of copper alloy for dental application. Materials and methods: Three types of copper alloy used in Thailand were selected (Cu-Al, Cu-Al-Ni and Cu-Zn). Ingots of these three alloys were prepared. The tensile test and potentiodynamic polarization for corrosion test were performed following ISO 1562: 2004 Dentistry-Casting gold alloys and ISO 10271: 2001 Dental metallic materials-Corrosion test method. The ultimate strength, 0.2% proof stress, percentage of elongation after fracture and modulus of elasticity were calculated from tensile stress-strain curves. Six specimens for each test were made from each alloy. Results: The percentage of elongation of Cu-Al, Cu-Al-Ni and Cu-Zn alloys were not significantly different (48.6, 52.1, and 53.3 percent, respectively). The proof stress of Cu-Al and Cu-Al-Ni alloys (88.5 and 72.1 MPa, respectively) were not significantly different, while that of Cu-Zn alloy (38.9 MPa) was the lowest. The ultimate tensile strength of Cu-Al alloy was significantly the highest (321.9 MPa), while that of Cu-Al-Ni and Cu-Zn alloys (207.1 and 215.9 MPa, respectively) were not significantly different. The modulus of elasticity of Cu-Al alloy was significantly the highest (122.9 GPa), while that of Cu-Al-Ni and Cu-Zn alloys (97.9, and 102.3 GPa) were not significantly different. The potentiodynamic curve of Cu-Zn alloy had no passive region, while the curve of Cu-Al alloy had a shorter passive region than that of the Cu-Al-Ni alloy. Conclusion: Regarding mechanical properties, Cu-Al alloy seemed the most suitable for post and core materials while Cu-Al-Ni alloy had the highest corrosion resistance. Thus, both Cu-Al and Cu-Al-Ni alloys showed promising properties for further development as appropriate post-and-core materials.