Fretting corrosion of Ti-6A1-4V vs. Ti-6A1-4V contact and Ti-Al-4V vs. zirconia: dental implant against abutment

摘要

Fretting corrosion experiments related to dental implant connections are under survey. The connections submitted to this tribocorrosive mechanism are between the dental implant part and the abutment. Two combinations of materials have been investigated corresponding to two links in actual junctions. The behaviour of fretting corrosion between titanium alloy (Ti-6A1-4V) against titanium alloy and titanium alloy against zirconia, zirconia stabilized with Yttria, in artificial saliva has been highlighted. The device is a Fretting corrosion machine that has been developed by Mines Saint-Etienne and TA (ex. Bose). The contact stress has been estimated from the actual junction between implant and abutment (Astra™ TX4.5, Dentsply™/Atlantis™). The average contact stress was of 130 MPa. The ionic strength was the same than the one of the human saliva, i.e. 0,154 mol.L~(-1). The total average wear volume of zirconia against titanium alloy was higher than the one related to titanium alloy against titanium alloy. The Open Circuit Potential (OCP) evolution concerning both couples was expected as well. The values were the same at the beginning and at the end with combination of titanium alloys. However the OCP evolution of metal combined with zirconia showed that the end-value was lower, sign of corrosion of metal even after fretting test. From results, fretting corrosion between zirconia and titanium alloy involves more damage and wear debris than titanium alloy against titanium alloy.