Mechanical and biological properties of Ti-(0-25wt%)Nb alloys for biomedical implants application.

James Kit Hon Tsoi,Danni Sun,Jiang Chen,Jun Cheng,Yuqing Zhang

doi:10.1093/rb/rbz042

James Kit Hon Tsoi, Danni Sun + Show 3 more

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https://doi.org/10.1093/rb/rbz042

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Abstract

Binary titanium–niobium (Ti–Nb) alloys have recently been attracted due to low Young’s moduli and non-toxic properties. This study explores the influence of low Nb content (0–25 wt%) on the comprehensive parameters of tensile stress–strain relationships (ultimate strength (σUTS), yield strength (σ0.2) and elastic modulus (E)), surfaces properties (Vickers microhardness, surface roughness (Ra), water contact angle (WCA), X-ray diffraction (XRD) and scanning electron microscopy (SEM)), corrosion resistance (in artificial saliva and lactic acid) and biological properties (cytotoxicity and alkaline phosphatase activity of MC3T3-E1 pre-osteoblasts) of Ti–xNb alloys (x = 5, 10, 15, 20 and 25 wt%), with using commercially pure grade 2 titanium (cp-Ti) as control. XRD results shown that all the Ti–xNb alloys comprised α + β Ti alloy phases, such that the β phase increased correspondingly with the increased amount of Nb in the alloy, as well as the reduction of E (69–87 GPa). Except Ti–5Nb, all other Ti–xNb alloys showed a significantly higher hardness, increased σUTS and σ0.2, and decreased WCA compared with cp-Ti. No corrosion was detected on Ti–xNb alloys and cp-Ti in artificial saliva and lactic acid solutions. The cytotoxicity of Ti–xNb alloys was comparable to that of cp-Ti in MC3T3-E1 pre-osteoblasts without interference from differentiation behaviour, but the proliferation rate of the Ti–5Nb alloy was lower than other groups. In overall, binary Ti–(10–25 wt%)Nb alloys are promising candidate for orthopaedic and dental implants due to their improved mechanical properties and comparable biological performance, while Ti–5Nb should be used with caution.

Highlights

Titanium (Ti) is an attractive biomaterial because of its osseointegration ability, relatively low elastic modulus and high corrosion stability
All Ti–xNb (x 1⁄4 5, 10, 15, 20 and 25 wt%) alloys comprised a þ b Ti alloy phases, and the increase of Nb content would increase the amount of b phase
There was a very minor amount of b phase in Ti–5Nb, and Ti–10Nb exhibited a minor but detectable amount of b phase, while b phase was dominant in the Ti–25Nb, which had very little a phase

Summary

Introduction

Titanium (Ti) is an attractive biomaterial because of its osseointegration ability, relatively low elastic modulus and high corrosion stability. Ti has received great attention in the orthopaedic and dental fields [1, 2]. Pure Ti has insufficient wear resistance and low load-bearing strength. This hampered the use of pure titanium in long-term applications such as implant. Titanium alloys, that were commented to be more mechanically advantageous [3, 4], would be more favourable in such an application.

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