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At least 19 recordsLinked to original sources
PubMed1999

Corrosion of stainless steel, nickel-titanium, coated nickel-titanium, and titanium orthodontic wires.

Orthodontic wires containing nickel have been implicated in allergic reactions. The potential for orthodontic wires to cause allergic reactions is related to the pattern and mode of corrosion with subsequent release of metal ions, such as nickel, into the oral cavity. The purpose of this study was to determine if there is a significant difference in the corrosive potential of stainless steel, nickel titanium, nitride-coated nickel titanium, epoxy-coated nickel titanium, and titanium orthodontic wires. At least two specimens of each wire were subjected to potentiostatic anodic dissolution in 0.9% NaCl solution with neutral pH at room temperature. Using a Wenking MP 95 potentiostat and an electrochemical corrosion cell, the breakdown potential of each wire was determined. Photographs were taken of the wire speci mens using a scanning electron microscope, and surface changes were qualitatively evaluated. The breakdown potentials of stainless steel, two nickel titanium wires, nitride-coated nickel titanium, epoxy-coated nickel titanium, and titanium were 400 mV, 300 mV, 750 mV, 300 mV, 1800 mV, and >2000 mV, respectively. SEM photographs revealed that some nickel titanium and stainless steel wires were susceptible to pitting and localized corrosion. The results indicate that corrosion occurred readily in stainless steel. Variability in breakdown potential of nickel titanium alloy wires differed across vendors' wires. The nitride coating did not affect the corrosion of the alloy, but epoxy coating decreased corrosion. Titanium wires and epoxy-coated nickel titanium wires exhibited the least corrosive potential. For patients allergic to nickel, the use of titanium or epoxy-coated wires during orthodontic treatment is recommended.

Coated Materials, Biocompatible↗
PubMed1996

Bone bonding behavior of titanium and its alloys when coated with titanium oxide (TiO2) and titanium silicate (Ti5Si3).

It has been proposed that the essential requirement for artificial materials to bond to living bone is the formation of bonelike apatite on their surfaces in the body. Recent studies have shown that titanium hydrogel and silica gel induce apatite formation on their surface in a simulated body fluid. In this study, the influence of titanium oxide and titanium silicate on the bonding of titanium alloys to bone was studied. Rectangular implants (15 x 10 x 2.2 mm) of titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were implanted into the tibial metaphyses of mature rabbits. At 8 and 24 weeks after implantation, the tibiae containing the implants were dissected out and subjected to a detaching testing. The failure load for titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were, respectively, 0.68 +/- 0.48, 0.22 +/- 0.46, 0.67 +/- 0.59, 2.18 +/- 0.71 and 2.03 +/- 0.41 kgf at 8 weeks, and 2.7 +/- 0.91, 2.58 +/- 1.29, 2.38 +/- 0.41, 3.79 +/- 1.7, and 2.79 +/- 0.87 kgf at 24 weeks after implantation. Histological examination by Giemsa surface staining, CMR, and SEM-EPMA revealed the coated titanium alloy implants directly bonded to bone tissue during early implantation. A Ca-P layer was observed at the interface of the coated implants and the bone. The results of this study indicated that TiO2 and Ti5Si3 can enhance the early bonding of titanium alloys to bone by inducing a Ca-P layer (chemical apatite) on the surface of titanium alloys. It also is suggested that the direct bone contact occurs in relation to the calcium and phosphorus adsorption onto the surface of the titanium passive layer formed during long-term implantation.

Alloys↗
PubMed2003

Effect of hydrogen peroxide on titanium surfaces: in situ imaging and step-polarization impedance spectroscopy of commercially pure titanium and titanium, 6-aluminum, 4-vanadium.

To analyze titanium's response to representative surgical wound environments, a study was conducted on commercially pure titanium (CPTi) and titanium, 6-aluminum, 4-vanadium (Ti-6Al-4V) exposed to phosphate-buffered saline (PBS) with 30 mM of hydrogen peroxide (H(2)O(2)) added. The study was characterized by simultaneous electrochemical atomic force microscopy (EC AFM) and step-polarization impedance spectroscopy (SPIS). Surfaces were covered with protective oxide domes that indicated topography changes with potential and time of immersion. Less oxide dome coarsening was noted on surfaces treated with PBS containing H(2)O(2) than on surfaces exposed to pure PBS. Electrical data deduced from current transients collected while stepping voltage between 0 V and 1 V indicated that charge transfer in hydrogen peroxide solutions was an order of magnitude larger than it was in pure PBS. Oxide (early) resistances of CPTi samples were higher than were Ti-6Al-4V oxide resistances in both types of solutions, but CPTi oxide resistance was lower in the hydrogen peroxide solution compared to pure PBS. Capacitance data suggest that CPTi oxide films thicken in hydrogen peroxide solution more than they do in pure PBS. Differences in electrical properties between CPTi and Ti-6Al-4V surfaces suggest that CPTi, but not Ti-6Al-4V, has catalytic activity on H(2)O(2) and that the catalytic activity of CPTi oxide affects its ability to grow TiO(2). Differences in electrical properties are related to catalytic and oxidative mechanisms that take place directly on the titanium oxide surface and in wound environments. The study provides a foundation and theoretic basis for the porous oxide model on commercially pure titanium exposed to hydrogen peroxide.

Aluminum↗
PubMedDate not supplied

[Biomechanic and histomorphometric studies of HIP titanium glass ceramic, a new implant material, compared with glass ceramics, titanium and titanium alloy].

Interfacial tensile strength and quantitative histomorphological properties of alloplastic implant materials for hard tissue application were studied in animal models. Physico-chemical bonding in the order of 1 N/mm2 of bone to glass-ceramic (Ceravital) was demonstrated independent of magnitude of surface roughness with mineralized bone in excess of 80% at the implant interface. No bone-bonding, but contact of mineralized bone at the metal surface was observed in pure titanium and titanium alloys (Ti6Al4V, Ti5Al2, 5Fe) with smooth surfaces. Rough or porous surfaced specimens, however, exhibited mechanical interlocking and interdigitation, thus yielding interfacial tensile strength of up to 4 N/mm2 in geometrically porous or madreporic surfaces. The new composite material HIP-Titanium-glass-ceramic (Ceravital) displayed physico-chemical bonding to bone as well as mechanical interdigitation within the secondary porous structure, thus giving support to expectations that HIP-Titanium-glass-ceramic coated implants should perform superior than bulk materials.

Animals↗
PubMed1998

An immunocytochemical study for lysosomal cathepsins B and D related to the intracellular degradation of titanium at the bone-titanium interface.

The morphological relationship between titanium and lysosomal proteinases, cathepsins B and D, at the bone-titanium interface using titanium-coated plastic implants placed for 28 days in the tibiae of 6-week-old rats was immunocytochemically investigated by the colloidal immunogold-silver method. Under light microscopy the titanium layer appeared to make direct contact with the bone and one or a few layers of slender cells were interposed between the bone and titanium. Ultrastructurally, the titanium came in contact with the bone or the slender cell layer through a 20 to 40 nm thin amorphous zone. The slender cells at the bone-titanium interface consisted of two types; one was an osteoblast type with glycogen granules which was found along the newly-formed bone facing titanium layer. The other was a fibroblast type which came in contact with the titanium layer and occasionally endocytosed the detached titanium fragments. In addition, some of the slender cells also showed degenerative changes. Immunocytochemically, cathepsins B and/or D were sometimes colocalized in some phagolysosomes with titanium fragments. These findings suggested that the fibroblast types at the bone-titanium interface may act as scavengers to remove both cell debris and titanium by means of some endocytotic ability, and lysosomal cathepsins also developed in response to the endocytosed titanium. The osteoblast type also appears to show a high degree of osteogenic activity around the titanium-coated plastic implants.

Animals↗
PubMed1996

Influence of titanium oxide and titanium peroxy gel on the breakdown of hyaluronan by reactive oxygen species.

The molecular events occurring at the interface between titanium and connective tissue were investigated in order to help explain the unique biocompatible properties of titanium implants and their successful osseointegration into bone tissue. In this study the influence of commercially pure titanium and titanium peroxy gels on the breakdown of the connective tissue component and serum derived factor, hyaluronan, by reactive oxygen species (ROS), produced during the insertion of an implant in vivo, was examined. Hyaluronan breakdown was monitored in vitro in the presence of a hydroxyl radical flux, generated in the presence and absence of titanium powder and discs. Parallel studies examined the breakdown of hyaluronan by hydroxyl radicals in the presence of a titanium peroxy gel, prepared by incubation of the titanium powder or discs in concentrated hydrogen peroxide. The hyaluronan degradation products were separated according to their hydrodynamic size by gel exclusion chromatography. Similarly, experiments were also performed examining the degradation of 2-deoxy-D-ribose by a hydroxyl radical flux in order to demonstrate the detrimental potential of the hydroxyl radicals and to provide a measure of the effectiveness of titanium and titanium peroxy gels as scavengers of ROS. Titanium reduced the harmful effects of the hydroxyl radicals on the breakdown of hyaluronan, presumably acting as a scavenger for the reactive species, possibly by absorbing them into its surface oxide layer, which spontaneously forms on the surface. In contrast, the formation of a titanium peroxy gel from the titanium powder or on the surface of titanium discs enhanced breakdown of both the hyaluronan chains and 2-deoxy-D-ribose. The implications of these findings with regards to the biocompatible nature of the titanium and the ability of these implants to successfully osseointegrate are discussed.

Biocompatible Materials↗
PubMed2001

Bioactive titanium: effect of sodium removal on the bone-bonding ability of bioactive titanium prepared by alkali and heat treatment.

As reported previously, bioactive titanium is prepared by simple alkali and heat treatment, and can bond to living bone directly. The purpose of this study was to accelerate the bioactivity of bioactive titanium in vivo. In in vitro study, sodium removal by hot water immersion enhanced the apatite-forming ability of bioactive titanium in simulated body fluid dramatically. The specific anatase structure of titania gel was effective for apatite formation in vitro. In the current study, we investigated the in vivo effect of sodium removal on the bone-bonding strength of bioactive titanium. Sodium-free bioactive titanium plates were prepared by immersion in an aqueous solution of 5 M NaOH at 60 degrees C for 24 h, followed by immersion in distilled water at 40 degrees C for 48 h before heating them at 600 degrees C for 1 h. Three kinds of titanium plates were inserted into rabbit tibiae, including untreated cp-Ti, conventional alkali- and heat-treated Ti, and sodium-free alkali- and heat-treated Ti. In vivo bioactive performance was examined mechanically and histologically after 4, 8, 16, and 24 weeks. Sodium removal enhanced the bone-bonding strength of bioactive titanium at 4 and 8 weeks postoperatively; however, its bone-bonding strength was inferior to that of conventional alkali- and heat-treated titanium at 16 and 24 weeks. Histological examinations after the detaching test revealed breakage of the treated layer in the sodium-free alkali- and heat-treated titanium group. In conclusion, sodium removal accelerated the in vivo bioactivity of bioactive titanium and achieved faster bone-bonding because of its anatase surface structure, but the loss of the surface's graded structure due to the complete removal of sodium decreased the adhesive strength of the treated layer to the titanium substrate. Further investigations are required to determine the optimum conditions for preparation of bioactive titanium.

Alkalies↗
PubMed1996

Titanium serum and urine levels in rabbits with a titanium implant in the absence of wear.

Although devices made of titanium and its alloy with 6% aluminium and 4% vanadium have been remarkably successful primarily in orthopaedic and dental applications, clinical reports have implicated the biological response to released metal from this class of metals as a cause of failure. It is our hypothesis that in the absence of wear, the amount of titanium released is small and will preferentially accumulate in local tissues. One important implication of this is that measurable quantities of titanium in serum and urine that have been observed in clinical studies result from mechanically induced or assisted release phenomena. In order to test this hypothesis, titanium levels in various tissues and fluids of animals both with and without titanium implants need to be determined. In this paper, we report the titanium concentration in serum and urine of rabbits in the absence of wear. Titanium fibre felts were implanted into the tibia of rabbits. At various time points, serum and urine samples were collected from these rabbits as well as from two groups of control rabbits. The samples were analysed for titanium concentration using electrothermal atomic absorption spectrophotometry. The data for the implant group show that titanium levels in serum and urine do not increase in comparison to controls up to one year after implantation. Some clinical studies have documented elevated titanium serum and urine levels in the presence of titanium-based prostheses. The different results from these studies can be resolved by considering titanium release mechanisms other than passive dissolution.

Analysis of Variance↗
PubMed2003

The effect of thermal cycling on the bond strength of low-fusing porcelain to commercially pure titanium and titanium-aluminium-vanadium alloy.

OBJECTIVES: Titanium-ceramic restorations are currently used in spite of the pending problem of titanium-ceramic bonding, which has only been partially solved. In addition, some titanium-ceramic systems appear to be susceptible to thermal cycling, which can cause weaker bond strength. The objective of this study was to evaluate the bonding characteristics of titanium porcelain bonded to commercially pure titanium (Ti-Cp) or titanium-aluminum-vanadium (Ti-6Al-4V) alloy as well as the effect of thermal cycling on bond strength. METHODS: A three-point-flexure-test was used to evaluate the bond strength of titanium porcelain bonded to commercially pure titanium and Ti-6Al-4V alloy according to DIN 13.927. To evaluate the effect of thermal cycling on the samples, half were thermal cycled in temperatures ranging from 4 degrees C (+/-2 degrees C) to 55 degrees C (+/-2 degrees C). Results were compared with palladium-silver (Pd-Ag) alloy bonded to conventional porcelain (control). Scanning electron microscope (SEM) photomicrographs were taken to characterize the failed surfaces in the metal-ceramic interface. Anova and Tukey's multiple comparison tests were used to analyze the data at a 5% probability level. RESULTS: Thermal cycling did not significantly weaken the bond strength of porcelain to titanium interfaces. There was no significant difference in bond strength between commercially pure titanium (23.60 MPa for thermal cycled group and 24.99 MPa for non-thermal cycled group) and Ti-6Al-4V groups (24.98 and 25.60 MPa for thermal cycled and non-thermal cycled groups, respectively). Bond strength values for the control group (47.98 and 45.30 MPa, respectively) were significantly greater than those for commercially pure titanium and Ti-6Al-4V combinations. SIGNIFICANCE: The bond strength of low fusing porcelain bonded to cast pure titanium or Ti-6Al-4V alloy was significantly lower than the conventional combination of porcelain-Pd-Ag alloy. Thermal cycling did not affect the bond strength of any group.

Alloys↗
PubMed1998

Evaluation of the biocompatibility of titanium-tantalum alloy versus titanium.

To evaluate the biocompatibility of a new titanium-tantalum alloy, with qualities superior to titanium alone, for use in oral implantology, fibroblast and epithelial cell lines were grown on plastic, titanium, copper, and titanium-tantalum supports. Studies using scanning electron microscopy, flow cytometry, and cytotoxicity assays were conducted to compare the different supports. Scanning electron microscopic observations showed high densities of fibroblasts and epithelial cells with well-developed attachment systems in the form of cytoplasmic projections. Cell densities were lower on titanium and titanium-tantalum surfaces than on plastic. Cell numbers, as determined by cytotoxicity assays, were significantly higher on plastic than on titanium or titanium-tantalum surfaces while fibroblasts proliferated better than epithelial cells on both metal surfaces. Flow cytometric analyses of cell cycles did not reveal any significant variations in the distribution of cells among the cycle phases on the three materials. We found no differences with regard to the parameters studied between titanium and the titanium-tantalum alloy.

Alloys↗
PubMed2000

Bioactive macroporous titanium surface layer on titanium substrate.

A macroporous titanium surface layer is often formed on titanium and titanium alloy implants for morphological fixation of the implants to bone via bony ingrowth into the porous structure. The surface of titanium metal was recently shown to become highly bioactive by being subjected to 5.0 M-NaOH treatment at 60 degrees C for 24 h and subsequent heat treatment at 600 degrees C for 1 h. In the present study, the NaOH and heat treatments were applied to a macroporous titanium surface layer formed on titanium substrate by a plasma spraying method. The NaOH and heat treatments produced an uniform amorphous sodium titanate layer on the surface of the porous titanium. The sodium titanate induced a bonelike apatite formation in simulated body fluid at an early soaking period, whereby the apatite layer grew uniformly along the surface and cross-sectional macrotextures of the porous titanium. This indicates that the NaOH and heat treatments lead to a bioactive macroporous titanium surface layer on titanium substrate. Such a bioactive macroporous layer on an implant is expected not only to enhance bony ingrowth into the porous structure, but also to provide a chemical integration with bone via apatite formation on its surface in the body.

Apatites↗
PubMed1996

Local accumulation of titanium released from a titanium implant in the absence of wear.

Titanium and its alloys, like the majority of metallic implant materials, release passive metal dissolution products. This raises the issues of amount and fate, i.e. transport, storage, and/or excretion of these metal dissolution products. In this paper we document titanium levels in tissues local to a commercially pure titanium implant in the absence of wear; compare these values to control tissues; and determine the relative contribution of the local accumulation to total release. Titanium fiber felts were implanted into the tibia of rabbits for periods up to 1 year. Bone and muscle tissue samples near the implant were collected. Using electrothermal atomic absorption spectrophotometry the samples were analyzed for titanium content. Compared to controls, titanium levels in the bone near the implant were elevated at 1-, 4-, and 12-month postoperative time points. The 12-month time point had higher periprosthetic bone titanium levels than both the 1- and the 4-month implant groups. Titanium levels in muscle tissue near the felt also indicated release was occurring. The data support the hypothesis that metal species released from titanium implants in the absence of wear have a limited solubility. As a result, they tend to remain in an area local to the implant.

Analysis of Variance↗
PubMed1990

Difference in tissue response to nitrogen-ion-implanted titanium and c.p. titanium in the abdominal wall of the rat.

Ion implantation modifies the surface properties of different materials. We have compared the biological properties of titanium implanted with nitrogen with those of pure titanium. Implants were inserted in the abdominal wall of rats. The implants with surrounding tissue were excised after 1 and 6 weeks, and embedded in epoxy resin. The bulk metal was removed electrochemically and the tissue cut for light and electron microscopy. Using this technique the implant surface, formed by a thin oxide layer, remains and appears in sections as a dense line. After 1 week both types of implants were surrounded by a fluid space containing proteins and scattered macrophages but few polymorphonuclear granulocytes. The fluid space was wider around ion-implanted titanium (52 +/- 22 microns) than around pure titanium implants (15 +/- 3 microns). After 6 weeks the fluid space had largely disappeared around both type of implants. Around pure titanium implants macrophages and fibroblasts, quantified in 1-micron-thick sections in the light microscope, were present in about the same concentration in the inner tissue zone (within 25 microns from the implant surface). Around ion-implanted titanium macrophages predominated in the inner zone and multinuclear giant cells were present in almost all sections. Around both type of implants fibroblasts increased and macrophages decreased with increasing distance from the surface. In the electron microscope macrophages close to the surface of pure titanium were of small size and had an ultrastructure indicating a low activity. Macrophages close to ion-implanted titanium were large and had an active appearance as indicated by the presence of large amounts of endoplasmic reticulum and large Golgi areas in the cytoplasm. Our observations indicate that modification of the surface properties of titanium implants by ion implantation changes the biological properties.

Abdominal Muscles↗
PubMed2003

Individual prefabricated titanium implants and titanium mesh in skull base reconstructive surgery. A report of cases.

Titanium implants can be shaped by traditional hand forming, press shaping, modular construction by welding, construction on full-size models shaped from CT coordinates and, most recently, by computer-assisted design and computer-assisted manufacturing (CAD/CAM) that consist in the direct prefabrication of individual implants by milling them out of a solid block of titanium. The aim of our study was to present a set of preliminary cases of an ongoing program of reconstructive procedures of the skull base using titanium implants. The subjects underwent ablative procedures of the skull base with reconstruction either by titanium mesh or individual prefabricated CAD/CAM implants. Six patients have been operated on successfully since 2000: two received prefabricated CAD/CAM titanium plates and four others underwent reconstruction with titanium mesh. The stability of CAD/CAM plates is superior to that of mesh, thus it is more useful in reconstructing large lesions of the frontal skull base and the temporal and occipital bones. Titanium mesh was successfully used for defects smaller than 100 cm(2) or where selected viscerocranial defects are complicated in design and less reproducible by CAD/CAM. The intraoperative design, shaping and adjustment characteristic of titanium mesh can be dispensed with when CAD/CAM implants are used. The 3-D data set used in the CAD/CAM process also operates in the navigated simulation and planning of the ablation contours, the latter being of great assistance in establishing the optimal future defect. As a disadvantage, CAD/CAM technology is more expensive than titanium mesh, and the process is time-consuming as it is carried out in advance of surgery.

Adult↗
PubMed2001

Long-term results following reconstruction of craniofacial defects with titanium micro-mesh systems.

Introduction: Reconstruction of craniofacial defects can be carried out with autogenous tissue (calvarium, rib, iliac crest), allogeneic implants (AAA-bone, lyophilized cartilage) or alloplastic material (methacrylate, hydroxyapatite, titanium implants and mesh systems). Selection of the implant material used for reconstruction is still controversial. Material and Methods: At the Department of Oral and Maxillofacial Surgery, Kantonsspital Luzern, 20 patients with defects in the craniofacial and/or orbito-ethmoidal region have been treated using titanium micro-mesh between 1991 and 1998. Two different mesh systems, micro-titanium augmentation mesh and dynamic mesh, have been used for bony reconstruction in non load-bearing areas. The defects were caused by acute trauma, osteomyelitis of the frontal bone and previous operations. The titanium micro-mesh was used with the following indications: (1) immediate reconstruction in the primary treatment of comminuted fractures with bone loss in non load-bearing areas, (2) treatment of contour irregularities (possibly in combination with bone or cartilage grafts). All patients were followed up clinically and radiographically at quarterly intervals for a year. Results: No wound infections, exposures or loss of the mesh have been observed. Long-term stability of the reconstructions was excellent. When walls of the paranasal sinuses were reconstructed complete repneumatisation took place. Conclusions: Advantages of this reconstructive technique are: (1) universal applicability (craniofacial, orbital, sinus defects, comminuted fractures); (2) stable 3-D reconstruction of complex anatomic structures were easily performed; (3) immediate availability with no donor site morbidity as bone or cartilage grafts were not necessary; (4) combination with bone or cartilage grafts is possible; and (5) very low susceptibility to infection. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗
PubMed2001

Application of sintered titanium alloys to metal denture bases: a study of titanium powder sheets for complete denture base.

The purpose of this study was the fabrication of titanium powder sheets to enable the application of sintered titanium alloys as metal denture bases. The effects of titanium particle shape and size, binder content, and plasticizer content on the surface smoothness, tensile strength and elongation of titanium powder sheets was investigated. To select a suitable ratio of powdered metal contents for application as a metal denture base, the effects of aluminum content in Ti sheets and various other powder metal contents in Ti-Al sheets on the density, sintering shrinkage, and bending strength were evaluated. Based on the results of the above experiments, we developed a mixed powder sheet composed of 83Ti-7Al-10Cr with TA45 titanium powder (atomized, -45 microm), and 8 mass% binder content. This titanium alloy sheet had good formability and ductility. Its sintered titanium alloy had a density of 3.2 g/cm3, sintering shrinkage of 3.8%, and bending strength of 403 MPa. The titanium alloy sheet is clinically acceptable for fabricating denture bases.

Aluminum↗
PubMed1999

Silicon nitride coating on titanium to enable titanium-ceramic bonding.

Failures that occur in titanium-ceramic restorations are of concern to clinicians. The formation of poorly adhering oxide on titanium at dental porcelain sintering temperatures causes adherence problems between titanium and porcelain, which is the main limiting factor in the fabrication of titanium-ceramic restorations. To overcome this problem a 1-microm thick Si3N4 coating was applied to a titanium surface using a plasma-immersion implantation and deposition method. Such a coating serves as an oxygen diffusion barrier on titanium during the porcelain firings. The protective coating was characterized in the as-deposited condition and after thermal cycling. Cross sections of Ti/Si3N4-porcelain interface regions were examined by various electron microscopy methods and by energy dispersive analysis of X-rays to study the Si3N4 film's effectiveness in preventing titanium oxidation and in forming a bond with porcelain. The experiments have shown that this Si3N4 coating enables significant improvement in Ti-ceramic bonding.

Dental Porcelain↗
PubMed1990

Bactericidal properties of a titanium-peroxy gel obtained from metallic titanium and hydrogen peroxide.

A stable titanium-peroxy-radical complex is formed when metallic titanium interacts with hydrogen peroxide. The radical appears as one component in an aqueous gel formed when excess peroxides have been (catalytically) decomposed. The interaction between titanium and hydrogen peroxide may be of importance also in vivo during an inflammatory response at the implant. We report in this paper on the bactericidal effects of the titanium gel in the lacto- and myeloperoxidase-halogen systems. Escherichia coli viable count was used to evaluate the bactericidal properties of the gel and of H2O2 for comparison. The gel had only small or no toxic properties at high dilutions. Higher concentrations of the gel had bactericidal properties similar to those of H2O2. The results indicate that at physiological pH, the decomposition products of the gel ae titanium hydroxide (Ti(IV)(OH-)4) and hydrogen peroxide (H2O2). It was found that the gel probably oxidizes glutathione directly in contrast to H2O2, which needs a peroxidase to do so. A model for the interaction between titanium and hydrogen peroxide is suggested. Its consequences for the properties of titanium in vivo are also discussed.

Chlorine↗