Corrosion behaviour and biocompatibility of a new dental noble AuPdAgTi alloy

The aims of the study were to investigate the electrochemical response of a new dental Au-20Pd-10Ag-5Ti alloy in artificial Carter-Brugirard saliva and to assess its biocompatibility using gingival fibroblast culture. Electrochemical techniques of potentiodynamic and linear polarization were used. Also, the open circuit potentials and the corresponding open circuit potential gradients were monitored for 5000 exposure hours. The gingival fibroblast response to Au-20Pd-10Ag-5Ti alloy was estimated by LDH-cytotoxicity, MTT cell proliferation assays, the assessment of substrate-dependent changes in extracellular fibronectin network, cell morphology and actin cytoskeleton organization. The cyclic potentiodynamic curves of Au-20Pd-10Ag-5Ti alloy exhibited a passive behaviour with transpassive dissolution of silver, without pitting corrosion. Open circuit potentials were finally stable at noble values. Open circuit potential gradients have low values that could not generate galvanic or local corrosion. The new Au-20Pd-10Ag-5Ti alloy did not promote cell damage and alterations in cell adhesion and morphological features, exhibiting a good biocompatibility.