The recovery force of Ti-Nb coated and uncoated TiNi shape memory alloy rods was investigated. The rods were 6.0 mm, 6.5 mm and 7.0 mm in diameter respectively. The mean transition temperature was 33.0 degrees C. The rods were stored at -18 degrees C and pre-bent with a three-point bending fixture, the span was 20. 0 centimeters and the deflections were 5.0 mm, 10.0 mm, 15.0 mm and 20.0 mm, respectively. The rods were then heated in a constant temperature saline solution chamber. The experimental temperature was 37.0 C and 50.0 C respectively. The recovery force was measured in a constant displacement mode on biomaterial test machine. The results showed that the recovery force of the memory alloy rod increased with increasing recovery temperature, rod diameter and deformation of both Ti-Nb coated and uncoated surface. The recovery force of Ti-Nb coated rods of 6.0 and 6.5 millimeter in diameter was lower than the uncoated rods in the same diameter. However, the recovery force of 7.0-mm-diameter rods showed no significant difference between coated and uncoated surface.
Alloys ; chemistry ; Biomechanical Phenomena ; Coated Materials, Biocompatible ; Niobium ; Temperature ; Titanium

PURPOSE: The purpose of this study was to investigate the electrochemical characteristics of nanotubular Ti-25Nb-xZr ternary alloys for dental implant materials. MATERIALS AND METHODS: Ti-25Nb-xZr alloys with different Zr contents (0, 3, 7, and 15 wt.%) were manufactured using commercially pure titanium (CP-Ti), niobium (Nb), and zirconium (Zr) (99.95 wt.% purity). The alloys were prepared by arc melting in argon (Ar) atmosphere. The Ti-25Nb-xZr alloys were homogenized in Ar atmosphere at 1,000℃ for 12 hours followed by quenching into ice water. The microstructure of the Ti-25Nb-xZr alloys was examined by a field emission scanning electron microscope. The phases in the alloys were identified by an X-ray diffractometer. The chemical composition of the nanotube-formed surfaces was determined by energy-dispersive X-ray spectroscopy. Selforganized TiO₂ was prepared by electrochemical oxidation of the samples in a 1.0 M H₃PO₄+0.8 wt.% NaF electrolyte. The anodization potential was 30 V and time was 1 hour by DC supplier. Surface wettability was evaluated for both the metallographically polished and nanotube-formed surfaces using a contact-angle goniometer. The corrosion properties of the specimens were investigated using a 0.9 wt.% aqueous solution of NaCl at 36℃±5℃ using a potentiodynamic polarization test. RESULT: Needle-like structure of Ti-25Nb-xZr alloys was transform to equiaxed structure as Zr content increased. Nanotube formed on Ti-25Nb-xZr alloys show two sizes of nanotube structure. The diameters of the large tubes decreased and small tubes increased as Zr content increased. The lower contact angles for nanotube formed Ti-25NbxZr alloys surfaces showed compare to non-nanotube formed surface. The corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface showed longer the passive regions compared to non-treatment surface. CONCLUSION: It is confirmed that corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface has longer passive region compared to without treatment surface.
Alloys* ; Argon ; Atmosphere ; Corrosion ; Dental Implants* ; Freezing ; Ice ; Nanotubes ; Niobium ; Spectrum Analysis ; Titanium ; Water ; Wettability ; Zirconium

Screw-shaped implants of commercially pure (c.p.) titanium, c.p. niobium, c.p. zirconium, and stainless(Sus 304) were inserted in the rabbit tibial over 12 weeks of follow-up. New developed torque gauge instrument was used to evaluate the implant holding power and a image analysis program coupled to a microscope was used for histomorphometry. The three best consecutive threads of each implant were measured. Quantitative analyses at 12 weeks revealed a partial bone contact to the four kinds investigated metals. There were no obvious adverse tissue reactions to any of the biomaterials. At 12 weeks the average removal torques for titanium, niobium and zirconium were better than that needed for Sus 304 screws, on the other hand high score of bony contact ratio of titanium and niobium were showed in comparison to those of zirconium and Sus 304. There was no significant differences in the amount of interfacial bone of zirconium and Sus 304 whereas there was significant differences in the torque forces of niobium and Sus 304. Three months after implant insertion, the average removal torque was 6.64 Ncm for the titanium, 6.57 Ncm for the niobium, 6.38 Ncm for the zirconium, and 4.25 Ncm for the Sus 304. On average bone contacts there were 51.24% in the titanium, 48.19% in the niobium, 31.79% in the zirconium, 23.54% in Sus 304. Biocompatibility of the titanium, niobium and zirconium was acceptable level in comparison to the Sus 304.
Biocompatible Materials ; Follow-Up Studies ; Hand ; Metals ; Niobium ; Titanium ; Torque ; Zirconium

OBJECTIVE: To evaluate the cytotoxicity of a new type of titanium alloy Ti-25Nb-10Ta-1Zr-0.2Fe by studying the induced proliferation of L929 cells in contrast with other titania widely used in clinical practice. METHODS: The cell line was treated with extracting liquid containing different concentrations of titanium alloys. The number and morphology of cells was observed under an inverted phase contrast microscope. MTT was used to measure the relative growth rate (RGR) and judge the cytotoxicity grade. Flow cytometry was used to observe cell cycle progression. RESULTS: The RGR of TNTZ group cells at the 3 time points was (93.7±0.8), (100.6±0.4), and (106.4±0.3); the cytotoxicity grade was 1, 0 and 0 after treating for 1, 3 and 5 days; with influence on neither the cell morphology nor the cell cycle. The flow cytometry showed that the sequence of S phase cells was Ti>TNTZ>TC4>blank control >TC4ELI, with no significant difference (P>0.05). None of the 4 materials inhibited the cell proliferation. CONCLUSION The cell morphology and proliferation are not affected by TNTZ. The new titaniu alloys shows good cyto-compatibility. The cytotoxicity is grade 0, meeting the clinical application standard.
Alloys ; toxicity ; Animals ; Cell Line ; Dental Alloys ; toxicity ; Fibroblasts ; cytology ; Mice ; Niobium ; Tantalum ; Titanium ; toxicity ; Toxicity Tests ; Zirconium

STATEMENT OF PROBLEM: The success of titanium implants is due to osseointegration or the direct contact of the implant surface and bone without a fibrous connective tissue interface. PURPOSE: The purpose of this study was to evaluate the osteoblast precursor response to titanium - 10 tantalum - 10 niobium (Ti-Ta-Nb) alloy and its sputtered coating. MATERIAL AND METHODS: Ti-Ta-Nb coatings were sputtered onto the Ti-Ta-Nb disks. Ti6-Al-4V alloy disks were used as controls. An osteoblast precursor cell line, were used to evaluate the cell responses to the 3 groups. Cell attachment was measured using coulter counter and the cell morphology during attachment period was observed using fluorescent microscopy. Cell culture was performed at 4, 8, 12 and 16 days. RESULTS: The sputtered Ti-Ta-Nb coatings consisted of dense nanoscale grains in the range of 30 to 100 nm with alpha-Ti crystal structure. The Ti-Ta-Nb disks and its sputtered nanoscale coatings exhibited greater hydrophilicity and rougher surfaces compared to the Ti-6Al-4V disks. The sputtered nanoscale Ti-Ta-Nb coatings exhibited significantly greater cell attachment compared to Ti-6Al-4V and Ti-Ta-Nb disks. Nanoscale Ti-Ta-Nb coatings exhibited significantly greater ALP specific activity and total protein production compared to the other 2 groups. CONCLUSIONS: It was concluded that nanoscale Ti-Ta-Nb coatings enhance cell adhesion. In addition, Ti-Ta-Nb alloy and its nanoscale coatings enhanced osteoblast differentiation, but did not support osteoblast precursor proliferation compared to Ti-6Al-4V. These results indicate that the new developed Ti-Ta-Nb alloy and its nanoscale Ti-Ta-Nb coatings may be useful as an implant material.
Alloys ; Cell Adhesion ; Cell Culture Techniques ; Cell Line ; Connective Tissue ; Edible Grain ; Hydrophobic and Hydrophilic Interactions ; Microscopy ; Niobium ; Organothiophosphorus Compounds ; Osseointegration ; Osteoblasts ; Tantalum ; Titanium

OBJECTIVEA novel biological piezoelectric ceramic was made by beta-tricalcium phosphate (beta-TCP) and lithium sodium potassium niobate (LNK) piezoelectric ceramics. To study its biocompatibility to osteoblast isolated from the cranium of 1-day-old Sprague-Dawley mice.

METHODSThe biological piezoelectric ceramic TCPLNK1/10, TCPLNK5/5 respectively mixed by beta-TCP and LNK piezoelectric ceramic at the ratio of 1/10 and 5/5. Then osteoblasts were used and seeded respectively on the negative and positive surfaces of TCPLNK1/10 and TCPLNK5/5. Growth and proliferation of the osteoblasts on TCPLNK1/10 and TCPLNK5/5 surfaces were evaluated in vitro by means of scanning electron microscopy (SEM) examination, fluorescence dyeing of osteoblast skeleton protein and MTT assay.

RESULTSCell morphology of osteoblast on positive and negative surfaces of TCPLNK1/10 and TCPLNK5/5 was normal, and both adhesion and growth characteristics showed better than control group. The growing osteoblasts on the TCPLNK1/10 negative surface were significantly higher than others. The negative surface of TCPLNK1/10 possessed better osteogenesis potential than others in vitro.

CONCLUSIONThe surface of TCPLNK may permit the imitation piezoelectric effect of natural bone for bone regeneration.

Animals ; Bone Regeneration ; Bone and Bones ; Calcium Phosphates ; Cell Proliferation ; Ceramics ; Mice ; Microscopy, Electron, Scanning ; Niobium ; Osteoblasts ; Osteogenesis ; Oxides ; Periosteum ; Rats ; Rats, Sprague-Dawley ; Skull

Variation in pH value of oral cavity circumstance causes decayed tooth. In this paper, corrosions of Ti-Fe-Mo-Mn-Nb-Zr dental alloys in various pH lactic acids were studied by immersion test. In the case of pH=4, which is an acidity slightly larger than that causes decayed tooth, Ti-Fe-Mo-Mn-Nb-Zr alloys are entirely corrosion-resistant, and the corrosion type is pitting. With the increase in acidity, the corrosion-resistance of Ti-Fe-Mo-Mn-Nb-Zr alloys deteriorates, and the corrosion type changes from pitting to intergranular corrosion. Fe ion is the most dissolved substance in impregnation, which means Fe goes against the corrosion-resistance of Ti alloys. Both results of thermodynamics calculation and X-ray photoelectron spectroscopy have shown that Mn2O3, Nb2O5 and TiO2 form oxide film on the surface of Ti-Fe-Mo-Mn-Nb-Zr alloys.
Corrosion ; Dental Alloys ; chemistry ; Humans ; Hydrogen-Ion Concentration ; Iron ; chemistry ; Lactic Acid ; chemistry ; Manganese ; chemistry ; Molybdenum ; chemistry ; Niobium ; chemistry ; Surface Properties ; Titanium ; chemistry ; Zirconium ; chemistry

PURPOSE: This study was performed to evaluate the osteogenic potential of 3mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) and niobium oxide containing Y-TZPs with specific ratios, new (Y,Nb)-TZPs, namely YN4533 and YN4533/Al20 discs. MATERIALS AND METHODS: 3Y-TZP, YN4533 and YN4533/Al20 discs (15 mm diameter and 1 mm thickness) were prepared and their average surface roughness (Ra) and surface topography were analyzed using 3-D confocal laser microscope (CLSM) and scanning electron microscope (SEM). Mouse pre-osteoblast MC3T3-E1 cells were seeded onto all zirconia discs and evaluated with regard to cell attachment and morphology by (CLSM), cell proliferation by PicoGreen assay, and cell differentiation by Reverse-Transcription PCR and Quantitative Real-Time PCR, and alkaline phosphatase (Alp) staining. RESULTS: The cellular morphology of MC3T3-E1 pre-osteoblasts was more stretched on a smooth surface than on a rough surface, regardless of the material. Cellular proliferation was higher on smooth surfaces, but there were no significant differences between 3Y-TZP, YN4533, and YN4533/Al20. Osteoblast differentiation patterns on YN4533 and YN4533/Al20 were similar to or slightly higher than seen in 3Y-TZP. Although there were no significant differences in bone marker gene expression (alkaline phosphatase and osteocalcin), Alp staining indicated better osteoblast differentiation on YN4533 and YN4533/Al20 compared to 3Y-TZP. CONCLUSION: Based on these results, niobium oxide containing Y-TZPs have comparable osteogenic potential to 3Y-TZP and are expected to be suitable alternative ceramics dental implant materials to titanium for aesthetically important areas.
Alkaline Phosphatase ; Animals ; Cell Differentiation ; Cell Proliferation ; Ceramics ; Dental Implants ; Gene Expression ; Mice ; Niobium ; Osteoblasts ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Titanium

In this study, the general toxicity tests including acute toxicity test, haemolysis test, MTT assay of Ti-Fe-Mo-Mn-Nb-Zr alloys were carried out. The morphology of these cells was also observed under phase-contrast microscope. By using X-ray photoelectron spectroscopy(XPS), the kind and mol% of element in surface film were studied. The kind and concentration of element in dipping fluid were investigated by ICP atomic emission spectrometry. The results showed the primary component is TiO2 in surface film. The dipping fluid of Ti-Fe-Mo-Mn-Nb-Zr alloys contains Fe 0.2-1.07 mg/l and Mn 0.16-0.5 mg/l; such dental materials are beneficial to health. No cytotoxic effect was disclosed by in vitro and in vivo tests. The level of cytotoxicity was grade 0 and 1; the haemolysis degree was 0.558%-0.642%, i.e. less than 5%. The cells growing in the extract showed normal morphology. These data indicate that Ti-Fe-Mo-Mn-Nb-Zr alloy, as a dental material, has good biocompatibility.
Animals ; Biocompatible Materials ; chemistry ; toxicity ; Dental Alloys ; toxicity ; Iron ; toxicity ; Male ; Manganese ; Mice ; Molybdenum ; toxicity ; Niobium ; toxicity ; Osmotic Fragility ; Rabbits ; Random Allocation ; Spectrometry, X-Ray Emission ; Titanium ; toxicity ; Zirconium ; toxicity

AIMThe piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated.

METHODOLOGYCold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague-Dawley rats were examined by a scanning electron microscopy (SEM) and methylthiazol tetrazolium (MTT) assay.

RESULTSThe results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts.

CONCLUSIONNiobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.

Animals ; Biocompatible Materials ; chemistry ; toxicity ; Bone Substitutes ; chemical synthesis ; toxicity ; Cell Adhesion ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Ceramics ; chemical synthesis ; toxicity ; Coloring Agents ; Electrochemistry ; Materials Testing ; Microscopy, Electron, Scanning ; Niobium ; toxicity ; Osteoblasts ; drug effects ; Oxides ; chemical synthesis ; toxicity ; Porosity ; Potassium ; toxicity ; Pressure ; Rats ; Rats, Sprague-Dawley ; Skull ; cytology ; Stress, Mechanical ; Surface Properties ; Tetrazolium Salts ; Thiazoles