In vitro corrosion of dental implants and restorative materials

In vitro corrosion of dental implants and restorative materials
11 March 2004
D.K. KANG, K.T. OH, and K.N. KIM, Yonsei Univ, Seoul, South Korea
IADR
Objectives: For the aesthetic and functional restoration of edentulous patients, recently dental implants have been used widely. Dental implants and restorative alloys are required with the high corrosion resistance. However, they can be corroded in the oral cavity. In this study, Ti G2 and G3, gold, silver, Co-Cr and Ni-Cr alloys were investigated for their corrosion resistance. Methods: Potentiodynamic and potentiostatic tests(open circuit potential(OCP) and current density at -250, 0 and 250 mV(SCE)) were performed in artificial saliva at 37 degree Celsius. Results: Corrosion of gold and silver alloys did not occur due to their immunity in artificial saliva. Co-Cr, Ni-Cr and pure Ti exhibited the high corrosion resistance by their own passivity. Gold, silver and Ti G2 exhibited the highest corrosion resistance, Ni-Cr alloy and Ti G3 did the relatively high corrosion resistance, and Co-Cr alloy did the low corrosion resistance. The OCPs of gold, Ti G2, Ni-Cr and silver were about 50, 20, 0 and -60 mV(SCE), respectively. The OCPs of Ti G3 and Co-Cr decreased with the immersion time. In the potential loading of -250 mV, cathodic current flowed to all samples, although the absolute values were different. In the potential loading of 0 mV, cathodic current flowed to the others except for Co-Cr alloy. Ti G2 and Co-Cr alloys showed anodic current and the others cathodic current in the potential loading of 250 mV. Conclusion: If the pure Ti is used as dental implant, gold and silver alloys are considered to minimize the adverse effects by galvanic corrosion, but the galvanic corrosion as well as the localized corrosion can be occurred in Co-Cr alloy. This work was supported by Brain Korea 21 Project for Medical Science, Yonsei University and Medical Research Center Project in 2003.