Electrochemical impedance applied to the corrosion behavior of dental amalgams in synthetic physiological fluids

• Main Author: Alves,V. A.
• Publication Date: 2009
• Other Authors: Souza,D. G., Reis,R. Q., Silva,L. A. da, Rossi,A.
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0870-83122009000200007
• topic: Dental amalgams; Electrochemical Impedance Spectroscopy; Corrosion, Mott-Schottky; Polarisation Curves

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