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PubMed1998

Titanium aneurysm clips: mechanical characteristics and clinical trial.

Titanium clip is well documented to reduce the artifact observed in computed tomography (CT) or magnetic resonance (MR) imaging and improve the quality of these images. There are, however, some demerits based on metallic characteristics including large spring portions, lack of long and fenestration clips, and difficulties to produce. We examined the mechanical characteristics of Sugita titanium aneurysm clips (product of 6 aluminium-4 vanadium-titanium) and investigate the safety in clinical use and the imaging quality compared with those of cobalt (Co) alloy clips. On mechanical test, Sugita titanium clips showed no significant difference in closing force compared with the conventional Co alloy clips. The closing force reduced about 10% after 100 times repeated opening in titanium clips in contrast with no remarkable changes in Co alloy clips. Sixty-four patients with ruptured or unruptured cerebral aneurysms (total number of 71 aneurysms) were treated with Sugita titanium clips through the microsurgical technique. None of the unfavorable outcome occurred in related to the titanium clips. Neither clip dislocation nor deformation was experienced in this series during the follow-up period. The clip artifacts seen in CT and MR image were markedly reduced, however, MR angiography had less quality to resolve anatomical structures due to an existence of vessel gap. These results indicate that in spite of some disadvantages, Sugita titanium clips allow safe and beneficial use routinely in aneurysm surgery insofar as the complete clipping is obtained.

Biomechanical Phenomena↗
PubMed1988

The reaction of peri-implant tissues to titanium alloy and apatite-coated implants during the healing phase.

Oral implantation has been a controversial dental therapeutic procedure. Many implant materials and designs are presently in progress of study to evaluate the long term response of peri-implant tissues, together with anticipated loading considerations. The purpose of this examination was to make clear whether a fibrous layer would form between bone and Titanium alloy and apatite-coated Titanium implants under stressed and unstressed conditions, during the healing phase after implantation. The in vivo evaluation of 10 implants were made on two dogs. The upper 2nd and 3rd and lower 3rd and 4th premolar teeth were extracted and the sockets allowed to heal for 3 months. The implants in the unstressed condition were completely submerged, and in the stressed condition they were left with their top 2 mm above the surface of the bone, so that after suturing the top of the implant was exposed to the oral environment. After the postoperative healing phase of 3 months, the animals were killed and the specimens were prepared for histological, SEM examinations and EDX analysis of the interface zone between bone and the implants. Histological examination showed a direct contact between the apatite-coated implant and new bone, so that the implant became anchored to bone without an intervening soft tissue layer and a similar result was obtained between the Titanium implant and bone in the unstressed condition. However the high magnification electron micrographs showed a thin connective tissue between the bead-blasted surface of the Titanium implant and bone, and this peri-implant tissue could be detached from the implant. In the stressed condition, a thin layer of fibrous tissue was interposed between the Titanium implant and bone. The high magnification electromicroscopical views of the interface zone between the bone and these implants showed coarse fiber bundles developed perpendicular to the Titanium surface and their terminal ends were confluent with the rugged Titanium surface presumably as a result of micro-movement during the 3 months healing phase. In this study, an adequate space for a development of fibro-anchorage was about 20-200 microns in width. If occlusal stresses were within permissible range in healing period, the relative motion of the implant and bone was then optimal for the formation of a fibro-anchorage. It could be suggested that an ideal stress transfer from the Titanium implant to bone might be achieved by this fibro-anchorage.

Animals↗
PubMed1993

Backscatter radiation at tissue-titanium interfaces. Biological effects from diagnostic 65 kVp x-rays.

The induced secondary electrons from a metal surface by diagnostic x-rays are thought to contribute to cell damage near the tissue-metal boundaries of metal implants. Titanium implants are becoming increasingly more popular for tissue reconstructions and it is rather often desirable to take radiographs of the operated area. In this study we compared the biological effects of radiation on cultured mammalian test cells grown on titanium plates with the radiation effects on cells that were grown on plastic control plates. In order to study the acute radiation effects on cell growth it was necessary to work with rather high radiation doses (0.7-5 Gy). Photon energies, suitable for diagnostic radiography in odontology, 65 kV, were applied. We found that the cells grown on titanium plates were, in terms of the applied dose in the surrounding culture medium, more sensitive to the irradiations than the cells growing on plastic plates. The survival curve for the cells on titanium had a steeper slope, showed no shoulder in the low-dose region and looked like curves normally obtained for high LET radiation. It was not possible to resolve to what degree the titanium-dependent changes were due to an increased dose near the titanium surface or to a change in the radiobiological effectiveness. Although there was a significant decrease in cellular survival near the metal, postoperative intraoral radiography after titanium implantations need not be excluded. The maximal doses given in odontological x-ray examinations are less than 1 mGy and, if the results in this study are applied, the biological effects near the titanium implant will correspond to biological effects in soft tissue of doses less than 20 mGy which is lower than the doses that give acute effects. The risk of acute healing disturbances are significant only at much higher radiation doses.

Animals↗
PubMed1994

Diffusion of elements in porcelain into titanium oxide.

The diffusion of elements of commercial porcelain for titanium into titanium oxide during heating was investigated. Titanium was deposited on three kinds of disk-shaped porcelains by vacuum-vaporization and the porcelains were then heated. A thin titanium oxide film was formed on the porcelains by the heating. X-ray photoelectron spectroscopy was used to characterize the surfaces of the porcelains with and without titanium oxide. Only sodium, potassium, and barium diffused into titanium oxide during heating, where they formed a complex oxide with titanium. The diffusion of these elements may be involved in the bonding of porcelain to titanium.

Barium↗
PubMed2002

In vitro study of collagen coating of titanium implants for initial cell attachment.

The aim of this study was to examine the influence of collagen coating on titanium on the initial attachment of human gingival fibroblasts for the development of the implant with periimplant soft tissue attachment. The morphological changes of cultured human gingival fibroblasts were investigated by scanning electron microcopy (SEM). Four different surfaces, i.e. non-coated mirror-polished titanium, collagen-coated titanium, non-coated tissue-culture polystyrene, and collagen-coated polystyrene were examined. Collagen coating of titanium was effective for enhancing the initial cell attachment. It is expected that collagen coating of titanium implants will improve the attachment of the peri-implant soft tissue to titanium at early stages after the implantation. SEM observation revealed the morphological effect of collagen coating on both titanium and polystyrene surfaces. Many lamellipodia and filopodia were recognized on collagen-coated titanium or polystyrene. Collagen coating improved the activity of human gingival fibroblasts.

Cell Adhesion↗
PubMed2002

Surface properties and biocompatibility of nitrided titanium for abrasion resistant implant materials.

Corrosion, other related properties and biocompatibility of surface nitrided titanium were investigated to examine its possible use as an abrasion resistant implant material. The nitrided layer about 2 microm thick composed of TiN and Ti2N was formed on titanium by a gas nitriding method. The dissolved amount of titanium ion in SBF was as low as the detection limit of ICP, and that in the 1% lactic acid showed no significant difference from titanium. The tissue reaction of the cylindrical implant in soft tissue of rats showed no inflammation, and fine particles of 1 microm induced phagocytosis, which was similar to titanium. The implantation in the femor showed the new bone formed in direct contact with implants. All the results suggested that the wettability, corrosion resistance, S. mutans adhesion and biocompatibility were nearly equivalent to those of titanium. The surface of nitrided titanium was promising, with biocompatibility comparable with titanium, as an implant material such as for an abutment part of a dental implant, which requires high abrasion resistance.

Animals↗
PubMed2006

Surface modification of titanium with hydrothermal treatment at high pressure.

Surface modification of titanium was investigated by means of hydrothermal treatment with a maximum pressure of 6.3 MPa (280 degrees C temperature) in CaO solution or water to improve bioactivity and biocompatibility. As a result, calcium titanate was formed on the titanium surface. Moreover, titanium oxide and titanium hydroxide layers on the surface increased as temperature and pressure increased. The surface-modified titanium was also immersed in a simulated body fluid (SBF) to estimate its bioactivity. Needle-like apatite precipitation was observed on all hydrothermal-treated titanium surfaces after immersion in SBF for four weeks. In particular, the apatite precipitation of titanium treated with 6.3 MPa in CaO solution was clearer and larger in amount than those of all other hydrothermal-treated specimens. Further, the amount of precipitate corresponded to the thickness of the surface-modified layer and the amount of calcium in the surface layer. The results suggested that surface modification of titanium with high-pressure hydrothermal treatment seemed to improve bioactivity and biocompatibility.

Biocompatible Materials↗
PubMed1987

Abnormalities of pulmonary function and pleural disease among titanium metal production workers.

The authors conducted a cross-sectional survey of respiratory disease among 209 titanium metal production workers. Work in areas where there was exposure to titanium tetrachloride and titanium dioxide particulates was associated with reductions in ventilatory capacity. Pleural disease (plaques and diffuse thickening) was present in the chest radiographs of 17% of the subjects and was associated with the duration of work in titanium manufacturing. It was also associated with past asbestos exposure. After control for asbestos exposure, it remained associated with titanium manufacturing. The findings are consistent with the hypothesis that titanium tetrachloride and titanium dioxide particulates may be associated with a reduction in ventilatory capacity and that the overall process of titanium manufacturing may be associated with unexpected pleural disease.

Adult↗
PubMed1998

[The role of fetus decalcified bone matrix (FDBM) in inducing pure titanium-bone implant integration].

Because of its high biological compatibility, titanium has been a good biomaterial. The implanted artificial bone made from titanium can contact with the vital and mature osseous tissue directly within 3-6 months, the so-called osteointergration. In order to promote the process of osteointergration, FDBM of rabbit was prepared and was combined with pure titanium so as to speed up osteointergration. The study focused on bone density, bone intergration rate, new bone growth rate around the pure titanium, and the Ca2+ and PO(4)3- density of titanium-bone interface. A control group of pure titanium inplant without FDBM was set up. The results showed FDBM had no antigenicity. It could induce and speed up the new bone formation at titanium-bone interface. The titanium-bone intergration time was within 2 months. It was suggested that there were more bone morphogenesis protein (BMP) or other bone induction and bone formation factors in brephobone than that in child and adult bone. As a kind of bone induction material, FDBM was easy prepared, cheap in price, easy to storage, no antigenicity and obvious bone-inductive function.

Animals↗
PubMedDate not supplied

Surface characterizations of variously treated titanium materials.

The attachment of cells to titanium surfaces is an important phenomenon in the area of clinical implant dentistry. A major consideration in designing implants has been to produce surfaces that promote desirable responses in the cells and tissues. To achieve these requirements, the titanium implant surface can be modified in various ways. This research was designed to elucidate the relationship between surface roughness (Ra) and contact angle (theta) of various engineered titanium surfaces of commercially pure titanium, titanium-aluminum-vanadium alloy (Ti-6Al-4V), and titanium-nickel (TiNi) alloy. The contact angle was measured using distilled water, 1% sodium chloride solution, human neutrophils, and osteoblast-like cells. Surface oxide crystallography was identified by transmission electron diffraction. It was found that: (1) there were no significant differences in contact angles among the 4 media; (2) for commercially pure titanium, a combined treatment (hydrofluoric acid/nitric acid/water --> sodium hydroxide --> oxidation) showed the lowest theta (10.51 degrees in water), while the surface treated with sulfuric acid showed the highest value (72.99 degrees in water); (3) for all commercially pure titanium samples, when theta is greater than 45 degrees, the contact angle increases linearly with Ra (hydrophobic nature) and the surface is covered with rutile-type oxide only, while the contact angle decreases linearly with Ra when theta is less than 45 degrees (hydrophilic nature) and the surface is covered with a mixture of rutile and anatase oxides; and (4) a similar trend was found on Ti-6Al-4V and TiNi surfaces.

Acid Etching, Dental↗
PubMed2002

Element mixing distribution and structure feature of fusion zone in laser welding between different alloys and pure titanium.

OBJECTIVE: To study micro morphology and element-mixing distribution of different alloys welded in laser and analyze the feasibility of laser welding different alloys. METHODS: Alloys and titanium were matched into 4 groups: Au-Pt with Ni-Cr; Au-Pt with pure Ti; pure Ti with Ni-Cr; Ni-Cr with Co-Cr. They were welded in laser. Changes in metallography after hybridization of crystalline grain, ranges of heat-affected zone and pores were observed through SEM with ultra-thin windowed X-ray energy atlas. Meanwhile 10 testing points were chosen with area of 300 micro m x 900 micro m along the welding surface from the side A alloy to the side B alloy, than the element mixing distribution and tendency were analyzed with X-ray energy atlas. RESULTS: 1. Hybridization of different alloys: (l) in the group of Au-Pt with Ti, there was titanium element mixing into Au-Pt tissue gradually and evenly on the Au-Pt side of the interface without clear boundary and increasing in size of crystalline grain. However, there was titanium crystalline grain increasing in size, irregular morphology and small sacks on the titanium side with clear boundary. (2) in the group of Ni-Cr with Ti, there was mixing regularly, slow transition and interlocks between crystalline grains on the Ni-Cr side of the in terface. Poor transition, clear boundary and small cracks were observed on titanium side. (3) in the group of Co-Cr with Ni-Cr, there was good transition, obscure boundary on both sides resulting from network, cylinder and branch structure growing. 2. Element-mixing distribution of different alloys. In fusion zone, the metal elements in matched groups mixed well and hybridized into new alloys except titanium blocks. The location of wave peak depended on the composition of alloys. Most of elements were from the alloy far from the fusion zone. CONCLUSION: The hybridization between pure titanium and any other alloys is not good The effect of laser welding different alloys is ideal except with pure titanium.

Alloys↗
PubMed2000

[Study on physical properties of titanium alloy sample fabricated with vacuum-sintered powder metallurgy].

OBJECTIVE: To investigate the physical properties of titanium alloy fabricated with vacuum-sintered powder metallurgy. METHODS: The titanium powders of three different particle sizes(-160mesh, -200 - +300mesh, -300mesh) were selected, and mixed with copper and aluminum powder in different proportions. Two other groups were made up of titanium powder(-200 - +300mesh) plated with copper and tin. The build-up and, condensation method and a double-direction press with a metal mold were used. The green compacts were sintered at 1000 degrees C for 15 minutes in a vacuum furnace at 0.025 Pa. In the double-direction press, the specimens were compacted at the pressure of 100 MPa, 200 MPa and 300 MPa respectively. Then the linear shrinkage ratio and the opening porosity of the sintered compacts were evaluated respectively. RESULTS: 1. The linear shrinkage ratio of specimens decreased with the increased compacted pressure(P < 0.05). There was no significant difference among the linear shrinkage ratios of three different titanium powders at the same compacted pressure(P > 0.05), but that of titanium powder plated with copper and tin was higher than those of other specimens without plating(P < 0.05). 2. The opening porosity of specimens decreased with the increased compacted pressure(P < 0.05). Three different sized particle of titanium powder did not affect the opening porosity at the same compacted pressure(P > 0.05). CONCLUSION: The composition of titanium-based metal powder mixtures and the compacted pressures affect the physical properties of sintered compacts. Titanium powder plated with copper and tin is compacted and sintered easily, and the physical properties of sintered compacts are greatly improved.

Dental Alloys↗
PubMed2003

Adhesive bond of veneering composites on various metal surfaces using silicoating, titanium-coating or functional monomers.

OBJECTIVES: This study compared the shear bond strength (SBS) between veneering composites and titanium (grade 1), a cobalt-chromium-alloy and a high precious-alloy, which were pretreated using silicoating systems, functional monomers or an experimental titanium-dioxide coating system. METHOD: The specimens were sized to rectangular plates of 20 x10 x 2mm(3) (l,w,h) and a composite cylinder (height of 4mm, diameter 5mm) was axially polymerized to the middle of the plates. After aging (24h or 150 d storage in distilled water at 37 degrees C, or thermal-cycling: 6000 x 5 degrees /55 degrees C) the SBS was determined. RESULTS: Independent of the type of metal and the conditioning/coating techniques the lowest SBSs were found after thermal-cycling. Titanium. The SBS of the silica coating systems and the functional monomers did not differ statistically on titanium. However, the titanium-dioxide coating method had significantly higher values than the other methods. Cobalt-chromium. The highest mean values were observed with the titanium-dioxide coating system and the phosphate acid ester. Precious alloy. No statistical significant different SBS was found for the silicoating and the titanium-dioxide coating methods, while the functional monomers were statistically significant (lower) different to both systems. CONCLUSION: Generally, the titanium-dioxide coating system achieved the highest SBS under different aging conditions and on all three different metal-surfaces.

Adhesives↗
PubMed2003

[The influence of surface conditioning on the shear bond strength of La-Porcelain and titanium].

OBJECTIVE: To determine the influence of different surface conditioning methods on bonding strength of low fusing porcelain (La-Porcelain) and titanium. METHODS: The surface of the samples were sandblasted for 2 min with 80-250 microns Al2O3 or coated for two times with Si-couple agent or conditioned by pre-oxidation. The shear bond strength was examined by push-type shear test with a speed of 0.5 mm/min in a universal testing machine. Scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) were employed to explore the relationship between bonding strength and microstructures, as well as the element diffusion at the interface between porcelain coating and titanium when heated at 800 degrees C. RESULTS: Bonding strength was not statistically different (P > 0.05) after sandblasting with Al2O3 in particle size ranged from 80 microns to 250 microns. When a Si-couple agent was used, bond of porcelain to titanium was significantly lower (P < 0.05). The shear bond strength of the porcelain to the pre-oxidized titanium surface remained unchanged after heating (P > 0.05). The SEM results revealed integrity of porcelain and titanium. CONCLUSION: La-Porcelain showed a small effect of surface coarseness. Sandblasting the titanium surface with 150-180 microns Al2O3 can be recommended as a method for better bonding between La-Porcelain and titanium. The Si-couple agent coating and pre-oxidation of titanium surface is unnecessary.

Aluminum Oxide↗
PubMedDate not supplied

The treatment of uncoated and titanium nitride-coated abutments with different instruments.

PURPOSE: The aim of this in vitro study of titanium abutments was to investigate the extent of treatment traces, the roughness depth, and the quantity of titanium or, in the case of coated abutments, titanium nitride (TiN) removed from the surface after treatment with various instruments. MATERIALS AND METHODS: Eleven uncoated, mechanically smoothed abutments and 11 TiN-coated abutments were used. The abutments were treated with titanium, steel, and plastic curettes; a rubber cup; an ultrasonic scaler with a steel tip; and an air scaler and cleaning powder. There were two 2 x 2-mm test fields on each abutment; each was subjected to standardized treatment with an instrument. The untreated surfaces of each abutment served as controls. The roughness depth (Rz) and profile height of treated and untreated surfaces were measured with a profilometer; profile height served as a basis for determining the amount of substance removed by treatment. The treatment traces were analyzed by scanning electron microscopy and light microscopy. RESULTS: Both the ultrasonic scaler and the steel and titanium curettes left pronounced traces on the uncoated abutments and increased Rz. Substantial substance removal was recorded following the use of the ultrasonic scaler (17.57 +/- 2.87 microm) and the steel curettes (8.48 +/- 2.81 microm) on the uncoated abutments. In tests of the coated abutments, measurable substance removal (4.80 +/- 0.99 microm) and increased roughness depth were noted only with use of the steel curettes. The treatment traces left by the other instruments were distinctly less pronounced than on the uncoated abutments. Light microscopy revealed detachment of the TiN coating after use of the ultrasonic scaler, titanium curettes, and steel curettes. Slight to moderate treatment traces were recorded after use of the rubber cup; no substance removal was observed. On the TiN-coated abutments, only slight treatment traces, if any, were recorded, and there was no substance removal. A planing effect (ie, an Rz decrease of 66.4%) was observed. The plastic curette and the air scaler caused no damage to the titanium or TiN surfaces. DISCUSSION AND CONCLUSION: The TiN-coated abutments displayed fewer treatment traces, less roughness depth, and less substance removal after being treated with various instruments. Two concerns, however, are the detachment of the coating after only few actions with steel and titanium curettes or with an ultrasonic scaler with steel tip, and the greater initial roughness depth of coated implants.

Air↗
PubMed2004

Effect of titanium-ion on the growth of various bacterial species.

There are a number of studies that explain the metabolism and roles of metallic titanium and titaniumion. One of the most intriguing results from these studies is the finding of metallic titanium having no bacteriostatic effects on oral bacterial species. In this research, the effects of titanium-ion on the growth of twenty-two bacterial species, some of which are commonly found in foods such as yoghurt, kimchi, and soy fermented products, were investigated. All but two bacteria, Escherichia coli and Pseudomonas aeruginosa appeared to be sensitive to titanium-ion. These two species were grown on 360 microg/ml of titanium-ions, and they were found to be resistant to the titanium-ion. Both the wild-type and plasmid-cured E. coli showed good growth in a medium with 200 microg/ml of titanium-ions. These results suggest that titanium-resistance was independent from the effects of the plasmid in E. coli.

Bacteria↗
PubMed2004

[Effects of TCP/HA-coating titanium on the adhesion behavior of human gingival fibroblasts].

OBJECTIVE: To investigate effects of hydroxyapatite (HA) and porous tricalcium phosphate/hydroxyapatite (TCP/HA)-coating titanium on the adhesion behavior of human gingival fibroblasts (HGFs). METHODS: Coatings of HA and duplex phases TCP/HA on titanium (Ti) were formed by ion beam assisted deposition (IBAD) method. Attachment, spreading, extracellular matrix (ECM) production, and focal adhesion plaque formation of HGFs were investigated on commercially pure (CP) titanium, HA-coated CP titanium and porous TCP/HA-coated CP titanium. After incubation of HGFs on these substrates, the number of attached cell, the area of cell spreading, immunostained ECM including fibronectin (FN) and type I collage, and vinculin (presenting the formation of focal adhesion plaque) were quantified by morphometric analysis using immunofluorescence microscope. RESULTS: TCP/HA and HA coatings exhibited that the attached cell number and cell spreading area were greater than those of CP titanium (P < 0.05), and the formation of focal adhesion plaque was earlier than that of uncoated substrate (P < 0.05). The number of attached cell and the formation of type I collagen on TCP/HA were more than those on Ti and HA. After 24-hour incubation on TCP/HA surface, the number of attached cell was 198.1 +/- 27.7 and the fluorescent intensity of type I collagen was 154.10 +/- 31.56. While under the same condition, the corresponding numbers for the CP titanium were 125.1 +/- 29.9 and 132.63 +/- 35.26. The differences between the two groups were significant (P < 0.05). CONCLUSIONS: In this study, the porous TCP/HA coating significantly facilitated the adherence of human gingival fibroblasts to Ti surface and could improve the biocompatibility of titanium.

Calcium Phosphates↗
PubMed2006

[Cr-Ti-Al-N complex coating on titanium to strengthen Ti/porcelain bonding].

OBJECTIVE: To study the feasibility of magnetron sputtering Cr-Ti-Al-N complex coating as an interlayer on titanium to enhance the titanium-ceramic binding strength. METHODS: With a three-point bending test according to ISO 9693, the binding strength of Duceratin (Degussa) to titanium substrate prepared with 4 different surface treatments (polishing, polishing and megnetron sputtering Cr, Ti, Al, and N complex coating, sandblasting, sandblasting and coating) was evaluated. Ti/porcelain interface and fractured Ti surface were examined using scanning electron microscopy with energy-dispersive spectrometry (EDS). RESULTS: The binding strength of polished and coated titanium/Duceratin was significantly higher than polished titanium group (P<0.05). The binding strength of sandblasted and coated titanium/Duceratin did not differ significantly from that of sandblasted titanium group (P>0.05), and the strength in the two sandblasted titanium groups was significantly higher than that in polished and coated titanium group (P<0.05). CONCLUSION: Megnetron sputtering Cr-Ti-Al-N complex on polished titanium can increase the titanium/porcelain binding strength. Megnetron sputtering coating is a promising Ti/porcelain interlayer.

Aluminum↗