Effects of Ti, Al and V Concentrations on Cell Viability

Science and Technology of Advanced Materials

Nagata

2012

Self Cite

Metal release from implantable metals and the properties of oxide films formed on alloy surfaces were analyzed, focusing on the highly biocompatible Ti-15Zr-4Nb-4Ta alloy. The thickness and electrical resistance (R p ) of the oxide film on such an alloy were compared with those of other implantable metals. The quantity of metal released during a 1-week immersion test was considerably smaller for the Ti-15Zr-4Nb-4Ta than the Ti-6Al-4V alloy. The potential (E 10 ) indicating a current density of 10 µA cm −2 estimated from the anodic polarization curve was significantly higher for the Ti-15Zr-4Nb-4Ta than the Ti-6Al-4V alloy and other metals. Moreover, the oxide film (4-7 nm thickness) formed on the Ti-15Zr-4Nb-4Ta surface is electrochemically robust. The oxide film mainly consisted of TiO 2 with small amounts of ZrO 2 , Nb 2 O 5 and Ta 2 O 5 that made the film electrochemically stable. The R p of Ti-15Zr-4Nb-4Ta was higher than that of Ti-6Al-4V, i.e. 0.9 cm 2 in 0.9% NaCl and 1.3 cm 2 in Eagle's medium. This R p was approximately five-fold higher than that of stainless steel, which has a history of more than 40 years of clinical use in the human body. Ti-15Zr-4Nb-4Ta is a potential implant material for long-term clinical use. Moreover, E 10 and R p were found to be useful parameters for assessing biological safety.Keywords: Ti-15Zr-4Nb-4Ta alloy, implantable metals, passive film, field-emission transmission electron microscopy, angle-resolved x-ray photoelectron spectroscopy, electrochemical stability evaluation

Section: Introductionmentioning

confidence: 99%

Comparisons of immersion and electrochemical properties of highly biocompatible Ti–15Zr–4Nb–4Ta alloy and other implantable metals for orthopedic implants

Science and Technology of Advanced Materials

Nagata

2012

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“…Since this alloy contains small amounts of vanadium, which has been shown to be cytotoxic at excess levels, there is concern over its effects on biological tissues. 1,2) The effect of aluminum on cell viability depends on surface roughness, surface treatment, strength of the aluminum oxide film and the extraction condition of the aluminum particles.…”

Section: Introductionmentioning

confidence: 99%

Dental Casting Properties of Ti-15Zr-4Nb-4Ta Alloy

2002

Mater. Trans.

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The dental casting properties of the Ti-15Zr-4Nb-4Ta alloy were compared with those of commercial pure Ti grade 2 and Ti-6Al-V alloy. Ti-15Zr-4Nb-4Ta dental castings were also surface-coated by TiN ion plating. Metal plates for complete and partial dentures, crowns and bridges were experimentally fabricated using the Ti-15Zr-4Nb-4Ta alloy. The cast surface down to a depth of about 200 µm had a highhardness layer due to the reaction with the dental investment. Also, there was no sharp increase in the current density caused by the breakdown of the passive film starting from the layer that reacted with the dental investment. The 0.2% proof strength, ultimate tensile strength, total elongation and Young's modulus of the Ti-15Zr-4Nb-4Ta castings, which were chemically polished by acid treatment after sandblasting, were 761 ± 33 MPa, 970 ± 31 MPa, 6 ± 4% and 90 ± 2 GPa, respectively. The micro-Vickers hardness of the TiN coated-surface was 740. The effect of TiN surface coating on the mechanical properties of the Ti-15Zr-4Nb-4Ta castings was negligible. The Ti-15Zr-4Nb-4Ta alloy exhibited a lower release of metal ions into the artificial saliva and 1% lactic acid solution than the Ti-6Al-4V alloy, and the quantity of metal ions released was less than 20% of that of titanium ions released from the Ti-6Al-4V alloy. The quantities of the titanium, zirconium and niobium ions released from TiN-coated Ti-15Zr-4Nb-4Ta casting into the artificial saliva were smaller than those released from the Ti-15Zr-4Nb-4Ta casting that was only chemically polished. Metal plates for complete and partial dentures, crowns and bridges were successfully fabricated using the Ti-15Zr-4Nb-4Ta alloy. A TiN-coated partial denture was also successfully fabricated using this alloy. The Ti-15Zr-4Nb-4Ta alloy with its excellent corrosion resistance and mechanical properties is expected to be used for dental prostheses in the future.

“…The α-medium solution contained 10 vol% fetal bovine serum and 7.5% NaHCO 3 solution (1 vol%). 24) The plate specimens were surface-finished with waterproof emery paper up to 1000 grit under running water and then ultrasonically cleaned. These specimens were placed in polypropylene bottles and separately sterilized in an autoclave for 30 min at 121…”

Section: Static Immersion Testmentioning

confidence: 99%

“…The effects of various metals on cell viability have been reported using metallic particles. [24][25][26] The colony formation ratio of the V79 cells derived from the lung tissue of a Chinese hamster and the growth ratios of the murine fibroblast L929 and murine osteoblastic MC3T3-E1cells relative to the control cells sharply decreased when the vanadium concentration in the medium was increased to 0.2 mg/L, and it became zero at approximately 0.5 mg/L. Since the quantities of the metal ions released into the medium were small (<0.3 mg/L) for titanium, zirconium, tantalum and niobium particle extractions, the relative growth ratios of the L929 and MC3T3-E1 cells were equal to 1 (non-cytotoxic).…”

Section: Introductionmentioning

confidence: 99%

Implant Applications of Highly Corrosion-Resistant Ti-15Zr-4Nb-4Ta Alloy

Gotoh

2002

Mater. Trans.

Self Cite

The release of metal ions from the Ti-15Zr-4Nb-4Ta alloy in pseudo body fluids was compared with those from Ti-6Al-4V and vanadium-free Ti-6Al-7Nb alloys widely used as implantable titanium alloys throughout the world, in order to choose an optimum acceleration solution for immersion testing. Bone plates, artificial hip joints of the cementless type and artificial tooth implants were experimentally fabricated using the Ti-15Zr-4Nb-4Ta alloy. The quantities of titanium ions released from the titanium alloys into phosphate-buffered saline, α-medium and fetal bovine serum were very small, and much lower than those released into 1.2 mass% L-cysteine, 0.05 mass%HCl and 1 mass% lactic acid solutions with lower pH values than the phosphate-buffered saline and α-medium. It was suggested that 1 mass% lactic acid solution was promising as an acceleration solution for immersion test. The quantities of titanium ions released from the Ti-15Zr-4Nb-4Ta alloy into fetal bovine serum, 1.2 mass% L-cysteine, 0.05 mass%HCl and 1 mass% lactic acid solutions were approximately 30% of those of titanium ions released from the Ti-6Al-4V alloy. The total quantity of zirconium, niobium and tantalum ions released from the Ti-15Zr-4Nb-4Ta alloy was much smaller than that of elements released from the Ti-6Al-4V and Ti-6Al-7Nb alloys. Bone plates, artificial hip joints and artificial tooth implants were successfully fabricated with the Ti-15Zr-4Nb-4Ta alloy using conventional manufacturing processes. The Ti-15Zr-4Nb-4Ta alloy with its excellent corrosion resistance is expected to become the preferential titanium alloy for implant applications in the future.