Fatigue behavior of Ti50Zr alloy for dental implant application

The microstructure, tensile and fatigue behavior of a hot-rolled Ti50Zr alloy applied for dental implant were investigated. The commercial Ti16Zr alloy was taken as a reference material. The load vs. number of cycling curves of the one-piece type Ti16Zr and Ti50Zr dental implants were tested according to ISO 14801 standard testing methods. The results show that the yield strength and fatigue limit of Ti50Zr alloy are up to 1001 +/- 8 MPa and 500 +/- 10 MPa, respectively, 23% and 32% higher than Ti16Zr alloy. The enhanced strength of Ti50Zr alloy is attributed to multiple mechanisms, including acicular martensite strengthening, Zr solid solution strengthening, nano-twins and dislocations strengthening. The maximum cycling loads of Ti50Zr implants in air, artificial saliva solution and with sand blasting plus acid etching (SLA) treated surface reach 400 N, 400 N and 350 N (5 x 10(6) cycles without failure), respectively, 33%similar to 75% higher than Ti16Zr implants. High surface roughness harms the fatigue performance of the Ti-Zr implants owing to the promotion role of notch-type defects to fatigue crack initiation. A corrosion-assisted fatigue process in artificial saliva solution under large load reduces the fatigue life of the Ti-Zr implants. Ti50Zr alloy is an ideal candidate material applied for dental implant with regards to its good biocompatibility, excellent mechanical properties and economic processing route. (C) 2019 Elsevier B.V. All rights reserved.