Resumo

ALVES, V. A. et al. Electrochemical impedance applied to the corrosion behavior of dental amalgams in synthetic physiological fluids. C.Tecn. Mat. [online]. 2009, vol.21, n.3-4, pp.36-43. ISSN 0870-8312.

The dental amalgam is a metallic alloy commonly utilized as a restorative material. In this study, Electrochemical Impedance Spectroscopy, polarisation curves and Mott-Schottky analysis were used to evaluate the physical characteristics of the passive film formed on amalgam surface; X-Ray and UV spectrophotometric analyses were also used to determine the alloy phases and possible soluble corrosion products, respectively. This study was done with Duxalloy^® and Tytin^® Plus samples in four different electrolytes: Phosphate Buffer Saline, Hank Solution, Artificial Saliva and NaCl 0.9%. In general, the longer the immersion time, the smaller the resistance, possibly due to film breakage; Duxalloy^® presented, at the end of 168 h of immersion, a higher resistance when compared to Tytin^® Plus. X-Ray analysis showed differences between the two studied brands. UV spectrophotometric analysis demonstrated a small absorption band at ~276 nm. These films kept their protective properties after 168 h of immersion

Palavras-chave : Dental amalgams; Electrochemical Impedance Spectroscopy; Corrosion, Mott-Schottky; Polarisation Curves.

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