Galvanic corrosion of two noble dental alloys in modified artificial saliva

Abstract

The composition of saliva is affected by Diabetes Mellitus with consequences in the oral homeostasis, being important to understand how dentistry alloys behave in this medium. This study aims to evaluate the corrosion resistance of two noble alloys, namely, Cerapall® 2 (Au-Pd-Cu-In) and Pontor® 2 (Au-Pt-Ag-Cu) using diverse artificial oral composition. Diabetic patients present reduced salivary flow rate, increased salivary glucose and more acidic salivary pH. The combinations of these factors contribute to a higher risk of dental decay in this group of patients [1]. The study was conducted in two oral salivary compositions (artificial saliva at pH 7.1 and artificial saliva with different concentrations of glucose at pH 6.0), at 37 °C, by cyclic and linear sweep voltammetry, electrochemical impedance spectroscopy and chronoamperometry. The potential and the current of the galvanic cell, obtained by coupling the two noble alloys, was recorded versus time, in the artificial saliva solution with (pH 6.0) and without glucose (pH 7.1), at 37 ºC. The ions release from the Cerapall® 2 and Pontor® 2 alloys was studied with and without the presence of glucose. SEM micrographs were obtained after 25 days immersion in artificial saliva, at 37 °C [2].

[1] AR Moreira, MSM Soares, IA Passos, FC Sampaio, Revista Odonto, 2007, 15(30), 78-82. [2] S Capelo, L Proença, JCS Fernandes and ITE Fonseca, Int. J. Electrochem. Sci., 2014, 9, 593 – 609.