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PubMed2000

The effect of alkali- and heat-treated titanium and apatite-formed titanium on osteoblastic differentiation of bone marrow cells.

This study was based on the hypothesis that osteogenesis is enhanced by growth of osteogenic cells on an apatitic surface. To test this hypothesis, the behavior of rat bone marrow cells on these surfaces was examined: commercially pure titanium (Cp Ti), alkali- and heat-treated titanium (AH Ti), and AH Ti incubated in a simulated body fluid to deposit crystalline hydroxyapatite on the surface (Ap Ti). The alkaline phosphatase (ALP) activity of the cells cultured on Ap Ti was significantly higher at day 7 and day 14 than the ALP activity observed for the other titanium surfaces. At day 14, the ALP activity on AH Ti was significantly increased compared with the ALP activity on Cp Ti. The amount of DNA per well increased nearly in parallel for each titanium. However, northern blot analysis at day 14 revealed that expression of osteocalcin and alpha1(I) collagen mRNA was higher in the cells cultured on Ap Ti than the cells cultured on AH Ti. The cells cultured on Cp Ti showed the lowest mRNA levels. After 7 days of cell-free culture in medium supplemented with 15% serum, X-ray photoelectron spectroscopy (XPS), and thin-film X-ray diffraction (TF-XRD) analysis showed that calcium phosphate had been deposited on the AH Ti (resulting in an increase in thickness with time). No phosphate was detected on the Cp Ti, even after day 14. This study indicates that Ap Ti provides the most favorable conditions for differentiation of bone marrow cells, and, at a later stage, AH Ti also provides favorable conditions, perhaps because of the formation of a surface layer of calcium phosphate. This potential for apatite formation may play an important role in osteoblastic differentiation.

Alkaline Phosphatase↗
PubMed2004

Preparation of different forms of titanium oxide on titanium surface: effects on apatite deposition.

Methods of preparing different types of titanium oxide (TiO(2)) and their effects on apatite deposition and adhesion on titanium surfaces were investigated. Forty-eight commercially pure titanium (Ti) discs were divided into four groups (12 per group) and each group was subjected to the following treatments: Group 1, heat treatment at 750 degrees C; Group 2, oxidation in H(2)O(2) solution followed by heat treatment; Group 3, dipping in rutile/gelatin slurry; and Group 4, dipping in anatase/gelatin slurry. Surface-treated Ti discs were immersed in a supersaturated calcium phosphate solution to allow apatite deposition. Results showed that the percentage of area covered by deposited apatite was highest in Group 4 compared to the other groups. Apatite deposited on Ti discs pretreated in H(2)O(2) solution (Group 2) demonstrated the highest adhesion to the titanium substrate. Results from this study indicated that surface treatment method affects the type of TiO(2) layer formed (anatase or rutile) and affects apatite deposition and adhesion on the Ti surface.

Apatites↗
PubMed1994

Better histology and biochemistry for osteoblasts cultured on titanium-doped bioactive glass: bioglass 45S5 compared with iron-, titanium-, fluorine- and boron-containing bioactive glasses.

In the present study we used an established cell culture model to compare Bioglass 45S5 with four other bioactive glasses. Small substitutions or additions of certain ions like iron, titanium, fluorine or boron modified the basic 45S5 glass network. We used several histological and biochemical parameters to interpret the results found in terms of the used model. Regarding 45S5 as a reference, we found that osteoblasts cultured on iron-doped bioactive glass showed a more flattened morphology, and both lower proliferation rate and osteoblast expression. Osteoblasts cultured on titanium-doped glasses also showed a flattened morphology, but higher proliferation and remarkably higher osteoblast expression. On fluorine- and boron-containing glasses the osteoblasts showed a rather compact morphology, a normal proliferation but only moderate osteoblast expression. With microprobe analysis it was shown that the formation of calcium and phosphorus on titanium-doped glass was relatively lower and the release of sodium slower when compared with 45S5. Osteoblasts cultured on titanium-doped bioactive glasses demonstrated superior histological and biochemical parameters when compared with the other glass types. Further research into the physico-chemical properties and the in vivo behaviour of doped bioactive glasses is recommended.

Alkaline Phosphatase↗
PubMed1997

The qualitative effects of various types of hygiene instrumentation on commercially pure titanium and titanium alloy implant abutments: an in vitro and scanning electron microscope study.

STATEMENT OF PROBLEM: Implant survival depends on proper and timely oral hygiene maintenance, and a wide variety of oral prophylaxis procedures have been recommended and used on implant abutments. PURPOSE: This in vitro study compared the surface quality of both commercially pure titanium and titanium-alloy implant abutments, subjected to various hygiene methods and instruments with a standardized, clinically applicable scaling force. MATERIAL AND METHODS: Commercially pure titanium and titanium-alloy abutments were exposed to five oral hygiene methods; a gold-alloy-tipped scaler, a high-grade resin scaler, a graphite-reinforced scaler, an air-powder abrasive system, and a rubber cup with tin oxide slurry. A customized test device that simulated the scaling motion and allowed the application of a standard load at the tip of the scaler was used. Scanning electron photomicrographs (x200) of the pretreatment and treated surfaces were obtained and compared qualitatively. RESULTS AND CONCLUSIONS: No significant surface alteration was produced by the air abrasive system. All other hygiene methods either created significant surface alterations, left residual particles on the abutment surfaces, or both.

Acrylic Resins↗
PubMed2001

Electrochemical corrosion of titanium and titanium-based alloys.

STATEMENT OF PROBLEM: Two varieties of unalloyed titanium, Ti-6Al-4V and NiTi, commonly are used in medical and dental fields. Several other types of alloys for potential use in these fields have been developed, including Ti-4.5Al-3V-2Mo-2Fe and vanadium-free alloys (Ti-5Al-2.5Fe and Ti-5Al-3Mo-4Zr). The corrosion of these alloys under simulated physiologic conditions is not known. Purpose. This study compared the corrosion behaviors of 6 titanium materials through electrochemical polarization tests in 37 degrees C Ringer's solution. MATERIAL AND METHODS: The applied voltage was potentiostatically scanned from -0.6 to 1.0 V. From polarization curves, the corrosion rate (averaged over 3 samples) for each alloy was calculated and compared with that of other alloys. Analysis of variance (ANOVA) and the Student-Newman-Keuls multiple range test were performed at a 95% overall confidence level to identify statistically significance differences in corrosion rates. Surface oxide films were identified by electron diffraction, and the electrolyte medium was analyzed by atomic absorption spectrophotometry after each alloy was tested. RESULTS: Commercially pure titanium and Ti-5Al-2.5Fe were the most resistant to corrosion; Ti-5Al-3Mo-4Zr, Ti-6Al-4V, and NiTi were the least resistant to corrosion. NiTi exhibited pitting corrosion along with transpassivation. CONCLUSION: Electron diffraction patterns indicated that all titanium alloys were covered mainly with rutile-type oxide (TiO(2)) after corrosion tests. The oxides that formed on Ti-5Al-2.5Fe were identified as a mixture of TiO(2) and Ti(9)O(17), and those that formed on NiTi were identified as a mixture of TiO(2) and Ni(2)Ti(4)O.

Alloys↗
PubMed2001

Notch sensitivity of titanium alloy, commercially pure titanium, and stainless steel spinal implants.

STUDY DESIGN: This is a biomechanical study comparing the fatigue life of stainless steel (SS), titanium alloy (TI), and commercially pure titanium (CP) rods that were notched using techniques essential to spine surgery. OBJECTIVES: To show the difference in fatigue life of the three rods and the effect on fatigue life of marks caused by techniques unavoidable in spine surgery. SUMMARY OF BACKGROUND DATA: Past studies have shown a decrease in the fatigue life of titanium when there is a defect or notch in the surface. This has been demonstrated with spinal and fracture implants, prosthetic joints, and in the materials science literature. Previous authors have recommended avoidance of techniques that mark the surface of titanium implants. METHODS: Four Texas Scottish Rite Hospital rods of each metal were prepared in four different ways: 1) no notch, 2) a French bender notch, 3) a top-loading connector--left on, 4) a top-loading connector--removed. The rods were fatigued in four point bending up to 1 million cycles. Before fatigue testing, two samples of each preparation were examined with electron microscopy. RESULTS: No SS rods failed. No TI rods without a notch or connector removed failed. One TI rod with the connector left in place failed (106,635 cycles). Three of the TI rods in the French-bender group failed (average, 87,663 cycles). One CP rod without a notch failed (358,957 cycles). No CP rods with the connector left in place failed. All CP rods with the connector removed failed (average, 230,094 cycles). All CP rods in the French bender group failed (average 120,817 cycles). The following differences were significant (P < 0.05): SS-TI and SS-CP in the French bender group; SS-CP and TI-CP in the connector removed group. Electron micrographs performed before fatigue testing showed cracks in the TI and CP rods that were marked with the French bender. CONCLUSION: Caution is recommended when bending TI or CP rods, or placing a connector and removing it when using CP rods in situations in which fatigue failure is a concern.

Alloys↗
PubMed2001

Effect of lipopolysaccharide contamination on the attachment of osteoblast-like cells to titanium and titanium alloy in vitro.

Failing implants with loss of alveolar bone are associated with gram-negative bacteria that carry lipopolysaccharide (LPS) in the bacterial cell wall. Bony regeneration around these implants is still an unpredictable procedure due to the many clinical factors involved. One important factor is the presence of contaminants such as LPS on the implant surface. The effect of implant-associated LPS on the attachment of bone cells to the implant surface is unknown. This project investigated the effect of LPS on the attachment of osteoblast-like cells (MC3T3-E1) to titanium and titanium alloy surfaces in vitro. We hypothesized that LPS would inhibit bone cell attachment either through loss of cellular attachment sites or alteration of cellular function. Three experimental approaches were used. First, alloy surfaces were exposed to LPS (100 microgram/mL) before the cells were allowed to attach. In the second approach, the cells were exposed to the LPS before they were allowed to attach. Last, the cells were allowed to attach before exposure to LPS. Cellular attachment to implant materials was measured by using a histochemical stain (MTT). The results indicated that LPS presence did not significantly (P > .05) alter osteoblast attachment to titanium or titanium alloy surfaces whether the exposure occurred before or after cellular adherence. It was concluded that LPS did not directly effect the attachment of the MC3T3-E1 osteoblasts to these implant surfaces in vitro. Further research is needed to define the clinical liabilities of LPS during implant placement and maintenance.

3T3 Cells↗
PubMed1989

[Casting of pure titanium and high fusing dental alloys by experimental casting machine. 7. Casting procedure for pure titanium denture frame].

The pure titanium cast frameworks were made using an arc-melting pressure and vacuum casting apparatus invented by Sato, and an experimental investment material. The salient features of the method and the cast frameworks were as follows: 1. The casting apparatus used was capable of making both complete and partial denture frameworks with pure titanium. It reduced casting errors and the interaction between titanium and the casting mold, producing less porous casted frameworks with a smooth surface. 2. The experimental investment material made a firm heat-resistant investment model with a smooth surface. It showed appropriate expansion and also excellent strength at room temperature after the burn out of the wax pattern. 3. The titanium casted frameworks fitted to the model and the oral cavity closely, and yielded satisfactory clinical results in more than 15 patients.

Dental Casting Investment↗
PubMed1990

[Stress analysis of titanium-hydroxyapatite implant. Effect of titanium diameter on reinforcement and calculation of implant diameter].

In order to evaluate the effect of titanium diameter on reinforcement of titanium-hydroxyapatite implant and calculate the diameter of the implant under loading, stress analysis was performed using the finite element method. In finite element model, 100% or 70% of root length was supported by PMMA in place of bone and the implant was loaded 15 kgf at 45 degrees of the implant axis. The results were obtained as follows, 1. In the case of 100% support, the titanium diameter had little effect on the reinforcement of the implant, whereas in the case of 70% support, it had much effect. 2. The diameter of this implant was calculated to be more than 3.7 mm under loading. From these results and the view point of manufacturing techniques, the diameter of this implant was supposed to need 4.0 mm and that of titanium was to be 2.0 mm.

Dental Implants↗
PubMed1999

Simultaneous or delayed placement of titanium implants in free autogenous iliac bone grafts. Histological analysis of the bone graft-titanium interface in 10 consecutive patients.

The aim of the present study was to histologically analyse the bone graft-titanium implant interface after six and twelve months of healing for a simultaneous approach and after six months for a delayed approach. For this purpose, screw-shaped c.p. titanium microimplants, 2 mm in diameter and 5 mm long, were placed and retrieved at different time intervals in ten consecutive patients with severely resorbed maxillae and treated with iliac cortico-cancellous bone grafts and titanium implants in a two-stage procedure. The histomorphometrical analyses of ground sections of the specimens showed a higher degree of bone-implant contact and more bone filling the implant threads in the delayed approach microimplants. This was probably due to the partly revascularized grafted bone in the delayed approach being able to respond to the surgical trauma, resulting in interfacial bone formation. It is concluded that the results from the present study favour the use of a delayed approach when using free autogenous bone grafts and titanium implants for reconstruction of the severely atrophied maxilla.

Alveolar Process↗
PubMed2000

[The researches on titanium and titanium alloy in dental use].

Although titanium and titanium alloy have been used in dental field for several years because of their excellent biocompatibility, corrosion resistance and mechanical properties, many practical problems remain to be solved. This review focuses on the practical problems and the prospects of the researches on titanium, including the development of new titanium alloy, the surface treating, the corrosion in oral, and the processability.

Corrosion↗
PubMed1992

The effect of stainless steel, cobalt-chromium, titanium alloy, and titanium on the respiratory burst activity of human polymorphonuclear leukocytes.

Although infection is a serious complication associated with the use of orthopedic prosthetic implants, the impact of the metal used in these devices on host defense is poorly understood. The authors investigated the effect of stainless steel, titanium, titanium alloy, and cobalt-chromium alloy on the respiratory burst of polymorphonuclear leukocytes (PMN), a vital component of bactericidal activity. In the presence of stainless steel powder or supernatants obtained from the incubation of stainless steel in buffer, superoxide production by PMN was significantly impaired. Titanium, titanium alloy, and cobalt-chrome alloy had no significant effect on superoxide production. Nickel and chromium, the only metal ions detectable in the stainless steel supernatant, did not impair superoxide production when tested at concentrations similar to those found in the supernatant. Inhibition of PMN superoxide production may play a role in the establishment and persistence of stainless steel device-related infections.

Cell Survival↗
PubMed1990

[Ultimate tensile strength of plasma- and laser-welded cast titanium (Titaniumer, Ohara)].

The ultimate tensile strength (UTS) of titanium castings (Titaniumer, Ohara) as cast and after plasma-welding, laser-welding and soldering was investigated according to DIN 13912. The UTS of titanium as cast was 567 (+/- 36) MPa. After plasmawelding UTS decreased by 69% on the average, after laser-welding by 20%, after soldering with Ag65Cu20Pd15 (1060 degrees C) by 46% and after soldering with Ag72Cu20Ti8 (980 degrees C) by 63%. The highest tensile strength was observed in laser-welded titanium under the conditions described.

Dental Casting Technique↗
PubMedDate not supplied

[Comparison of the biological tolerance of titanium and titanium alloys in human gingiva cell cultures].

Mirror-finished solid specimens of pure titanium and the titanium alloys Ti-6Al-4V as well as Ti-5Al-2.5Fe showed no effects on the growth behavior and cell morphology of human gingival epithelial cell and fibroblast cultures. The growth of the cells contacting all three materials was uninhibited. SEM revealed growth of fibroblasts on the surfaces of the specimens, too. No differences could be found between the biocompatibility of titanium alloys and that of pure titanium. The formation of a stable surface oxide layer providing resistance to corrosion may be decisive.

Alloys↗
PubMedDate not supplied

An evaluation of skeletal attachment to LTI pyrolytic carbon, porous titanium, and carbon-coated porous titanium implants.

Porous titanium, carbon-coated porous titanium, and low-temperature isotropic (LTI) pyrolytic carbon transcortical implants were placed in the femora of mongrel dogs. Mechanical and histologic analyses were performed in specimens that remained in situ for six months. Qualitative histologic results indicated that the bone formed a direct appositional interface with as-deposited LTI carbon. The bone tissue response to the two systems with porous coatings was similar. Both systems showed little fibrous tissue interposition and a high degree of mineralized bone ingrowth. The ingrown bone was well organized. However, there was some evidence that the ingrown bone mineral differed significantly from the bulk bone mineral. The only difference between carbon-coated and uncoated porous systems was a significant increase in the percentage of bone ingrowth, with carbon-coated specimens having a 4% increase in bone volume. The strength of appositional attachment to LTI carbon was shown to be at least one order of magnitude weaker than bone ingrowth attachment to the porous systems. The interface shear stiffness of the two porous systems was equivalent; however, the attachment shear strength of bone growth into carbon-coated porous titanium was significantly increased compared with that of bone growth into the uncoated porous titanium. Correlation of the percentage of bone ingrowth and pushout strength was also found to be statistically significant, suggesting that the presence of the carbon coating enhanced bone ingrowth, which resulted in significantly increased shear strengths.

Animals↗
PubMedDate not supplied

Marginal fit of machine-milled titanium and cast titanium single crowns.

Eighteen type IV dental stone dies were fabricated from a metal master die that replicated a tooth prepared to receive a metal ceramic crown. They were divided into three groups according to the type of crowns to be made: (a) machine-milled, spark-eroded titanium crowns (Procera); (b) cast titanium crowns; and (c) noble alloy crowns (as the control). The control specimens showed the smallest mean marginal openings at 25 microns and were significantly different from both the machine-milled crowns (54 microns) and the cast titanium crowns (60 microns). The two types of titanium crowns were not significantly different from each other.

Analysis of Variance↗
PubMed1998

Nanoporous alkoxy-derived titanium oxide coating: a reactive overlayer for functionalizing titanium surface.

Effective immobilization of bioactive substances such as adhesive proteins, synthetic peptides and growth factors on metallic substrates is required for a number of medical applications. In the present work, evidence is presented to show that an alkoxy-derived nano-porous titanium oxide coating, synthesized electrochemically on titanium in methanolic electrolytes, may act as an effective interface for functionalizing a titanium surface. It is demonstrated that nanoporous oxide coatings could facilitate fast diffusion of small organic molecules within the oxide network and form strong chemical bonds with the functional groups of these molecules at room temperature. Fourier transformed-infrared spectroscopy was used to investigate the nature of the interfacial interactions between the oxide network and a range of molecules containing COOH, OH, NH2, C=O and phosphoric acid functional groups. The results indicate that the nanometre-sized oxide clusters within the coating may play an essential role in effective immobilization of organic molecules by providing numerous binding sites for chemisorption of these species. The surface-derivatized oxide coating may provide a solid phase for the subsequent attachment of a broad range of biochemically active molecules on the titanium surface.

Journal Article↗
PubMed1986

The biological response to titanium and titanium-aluminium-vanadium alloy particles. I. Tissue culture studies.

One aspect of the biological response to titanium and titanium-aluminium-vanadium alloy was investigated by exposing primary cultures of human synovial fibroblasts and mouse peritoneal macrophages to particulate preparations of these materials. Both cell types appeared to be unaffected by either material as judged by microscopical examination. A small but significant release of lactate dehydrogenase was detected from both cell types in response to their exposure to the particulate material indicating that some cell damage occurred. Macrophages also exhibited a small release of the two lysosomal enzyme markers beta-glucuronidase and N-acetyl-beta-D-glucosaminidase. This indicates that these materials may have a mild inflammatory potential. No soluble metal could be shown to have dissolved from the particulate alloy or from pure titanium.

Alloys↗