Titanium Release Research Articles

Atomic layer deposited TiO2 nanofilm on titanium implant for reduced the release of particles.

Objective: Titanium implants are widely used in surgeries for their biocompatibility and mechanical properties. However, excessive titanium particle release can cause implant failure. This study explores Atomic Layer Deposition (ALD) to coat commercially pure titanium (Cp-Ti) with TiO2, aiming to improve its frictional and corrosion resistance while reducing particle release. By comparing TiO2 films with varying ALD cycle numbers, we assess surface properties, particle release, friction, and corrosion performance, providing insights into mitigating particle release from implants. Methods: Cp-Ti surfaces were prepared and coated with TiO2 films of 100, 300, and 500 ALD cycles. Surface characterization involved SEM, EDX, and XRD. Friction was tested using SEM, nanoindentation, and ICP-MS. Corrosion resistance was evaluated through immersion tests and electrochemical analysis. Cytotoxicity was assessed using BMSCs. Results: Surface characterization revealed smoother surfaces with increased ALD cycles, confirming successful TiO2 deposition. Friction testing showed reduced friction coefficients with higher ALD cycles, supported by nanoindentation results. Corrosion resistance improved with increasing ALD cycles, as evidenced by electrochemical tests and reduced titanium release. Cytotoxicity studies showed no significant cytotoxic effects. Conclusion: ALD-coated TiO2 films significantly enhance frictional and corrosion resistance of titanium implants while reducing particle release. The study underscores the importance of ALD cycle numbers in optimizing film performance, offering insights for designing implants with improved properties.

In Vitro Comparison to Evaluate Metal Ion Release: Nickel-Titanium vs. Titanium-Molybdenum Orthodontic Archwires.

Background When metals used in orthodontic materials are exposed to the oral environment, teeth, and gingivae over an extended period of time, they may gradually deteriorate. As a result, the patient is exposed to higher concentrations of metals and metal ions than what they would be exposed to through food and other sources. The goal of the current in vitro experiment was to evaluate and contrast the metal ion release from orthodontic archwires made of titanium-molybdenum alloy (TMA) and nickel-titanium (NiTi). Methods For 90 days, 20 orthodontic archwires in each group were immersed in 50 milliliters of simulated saliva using different containers. Atomic Absorption Spectrometry (AAS) (Shimadzu Corporation, Kyoto, Japan) was used to assess and compare metal ion emission. The unit of measurement is parts per million (PPM). Results The findings indicated that the discharge of nickel metal from the NiTi archwire (Group A) was much higher than that from the TMA archwire (Group B), with a statistical significance level of p < 0.001. It was discovered that Group B's release of titanium was statistically significantly (p < 0.05) higher than Group A's titanium release, which did not include the release of any other metals. Conclusion The study findings indicated that the amounts of metal ions released from the orthodontic archwires made of titanium molybdenum and nickel-titanium alloy were within safety limits.

Stability of ranibizumab during continuous delivery from the Port Delivery Platform

The Port Delivery System with ranibizumab (PDS) is an innovative intraocular drug delivery system that has the potential to reduce treatment burden in patients with retinovascular diseases. The Port Delivery Platform (PD-P) implant is a permanent, indwelling device that can be refilled in situ through a self-sealing septum and is designed to continuously deliver ranibizumab by passive diffusion through a porous titanium release control element. We present results for the studies carried out to characterize the stability of ranibizumab for use with the PD-P. Simulated administration, in vitro release studies, and modeling studies were performed to evaluate the compatibility of ranibizumab with the PD-P administration components, and degradation and photostability in the implant. Simulated administration studies demonstrated that ranibizumab was highly compatible with the PD-P administration components (initial fill and refill needles) and commercially available administration components (syringe, transfer needle, syringe closure). Subsequent simulated in vitro release studies examining continuous delivery for up to 12 months in phosphate buffered saline, a surrogate for human vitreous, showed that the primary degradation products of ranibizumab were acidic variants. The presence of these variants increased over time and potency remained high. The stability attributes of ranibizumab were consistent across multiple implant refill-exchanges. Despite some degradation within the implant, the absolute mass of variants released daily from the implant was low due to the continuous release mechanism of the implant. Simulated light exposure within the implant resulted in small increases in the relative amount of ranibizumab degradants compared with those seen over 6 months.

Titanium dioxide release behavior during wash of UV-protective garments by total reflection X-ray fluorescence

The increasing worldwide use of different kinds of clothes with ultraviolet protection in recent years, in particular employing titanium dioxide nanoparticles, is driving the researchers’ attention to the possible environmental problems due to titanium release. This study aims at determining the amount of titanium released from seven ultraviolet-protective garments into the wash water employing total reflection X-ray fluorescence spectrometry. For this, a wash protocol was designed based on the international standard ISO 105-C06:2010 and the literature. Pieces (4 cm × 10 cm) of textile were sampled from the garments and submitted 30 times to the wash protocol. The wash water produced in each wash was then prepared for total reflection X-ray fluorescence analysis. Results showed that the titanium released in 30 washes was between 8.6 ± 1.3 µg/L and 168 ± 3 µg/L. Every sample released titanium in the first to third wash, except sample 1, which first released titanium in the 18th wash. The greatest titanium release in one single wash was also the 18th wash of sample 1, which released 77 ± 2 µg/L. These results showed the good performance of total reflection X-ray fluorescence spectrometry in quantifying low titanium amounts in wash water, which is a hard task even for well-established analytical methods.

Quantifying the Release of Titanium From the Titanium Dioxide-Impregnated Composites Used in Orthodontic Bonding.

Previous literature data has extensively assessed the biocompatibility of various orthodontic adhesives and their components, where the results of most of the studies showed cytotoxic effects of different degrees owing to the unbound molecules released structurally from the cured components. The present in-vitro study was aimed to assess the release of titanium dioxide nanoparticles in the artificial saliva from the orthodontic composites impregnated with titanium dioxide nanoparticles of 5% w/w (weight/weight) and 1% w/wused for metal brackets bonding. The study assessed 160 teeth extracted freshly during orthodontic treatment and divided into two groups of 80 samples, each that bonded to orthodontic brackets having 5% w/w and 1% w/w composites with titanium dioxide nanoparticles kept in the artificial saliva.Quantification was done for 5% w/w and 1% w/w composites having titanium nanoparticles with inductively coupled plasma mass spectroscopy at 24 hours, two, four, and six months. It was seen that in teeth with 1% titanium dioxide, the greatest titanium release was seen at two months, with non-significant release after two months.In teeth with 5% w/w titanium dioxide nanoparticlesshowed significant titanium release all the time.A significantly greater titanium dioxide release on increasing concentration from 1% to 5% was seen for the 5% w/w group at all the assessment times. The present study concludes that a higher release of titanium is seen in 5% w/w composite containing titanium dioxide nanoparticles, and the concentrations of 1% and 5% can be safely used and are considered to be within permissible limits.

Quantitative determination and antibacterial properties of TiO2 nanoparticle-doped glass ionomer cement: an in vitro study.

The aim of the present study is to determine the amount of titanium ions released into the artificial salivary medium by modified glass ionomer cement (GIC) doped with 3% and 5% (w/w) titanium dioxide nanoparticles (TiO2-NPs), and to evaluate their antibacterial properties. 120 cylindrical discs with a diameter of 4 mm and a height of 6 mm were made with 3% and 5% w/w modified GIC containing TiO2 NPs, divided into two groups of 60, and immersed in a chemically synthesized salivary medium. The samples were quantified over four-time periods: 24 hours, two months, four months, and six months, using inductively coupled plasma mass spectroscopy (ICP-MS), antibacterial properties were evaluated by means of colony forming count (CFU) method. The amount of titanium ions released from the discs that received 3%(w/w) TiO2 was highest in the first two months, with no significant release at successive intervals. Also, the second group, which included 5% (w/w) TiO2, saw a considerable ion release at every interval, with the second month seeing the maximum release. The levels in the 5% (w/w) group were consistently higher when the two concentrations were compared at each of the four time points, indicating a considerable increase in titanium release and antibacterial property with a concentration increase from 3% to 5%. 3% and 5% (w/w) concentrations may be considered safe and exhibit significant antimicrobial effect, titanium ions were discharged at higher rates in 5% (w/w) modified GIC containing TiO2-NPs than in 3% (w/w) modified GIC containing TiO2-NPs.

In-vitro characterization of ranibizumab release from the Port Delivery System

The Port Delivery System with ranibizumab (PDS) consists of an implant that is a permanent, indwelling drug delivery device that can be refilled through a self-sealing septum and is designed to continuously release a customized formulation of ranibizumab into the vitreous by passive diffusion through a porous titanium release control element. Target release rates of ranibizumab via the implant used in studies of the PDS in patients with neovascular age-related macular degeneration were selected based on clinical and pharmacokinetic (PK) data from previously conducted intravitreal ranibizumab injection studies. In-vitro testing was performed to verify release rates with a range of ranibizumab concentrations before the phase II Ladder (NCT02510794) and phase III Archway (NCT03677934) trials of the PDS. Implants were filled with ranibizumab and were regularly transferred to new buffer-containing tubes to represent ocular ranibizumab clearance and release kinetics. Ranibizumab concentrations were measured and release rates calculated. Release rate data were fit to an exponential model and compared with expected release kinetics of diffusion. Release profiles of the implant releasing ranibizumab at concentrations of 10 mg/mL, 40 mg/mL, and 100 mg/mL were determined in the pre–phase II in-vitro studies. At day 3.5, mean (SD) ranibizumab release rates were 1.75 (0.07), 6.42 (0.35), and 16.69 (0.67) μg/d for PDS 10 mg/mL, 40 mg/mL, and 100 mg/mL, respectively. At month 6, mean (SD) release rates were 1.68 (0.05) and 4.16 (0.05) μg/d for PDS 40 mg/mL and 100 mg/mL, respectively. Measured release rates were within 90% of theoretical release rates during the course of drug release. PDS 100 mg/mL released 73% (SD, 1.92) of drug by month 6. In the pre–phase III in-vitro studies, mean (SD) release rates with PDS 100 mg/mL were 17.97 (0.90), 4.44 (0.11), and 2.45 (0.08) μg/d at 3.5 days, 6 months, and 9 months, respectively. Cumulative release (SD) was 73% (1.92) by month 6 and 87% (1.88) by month 9. The sustained, continuous, and reproducible release from the PDS observed in the in-vitro studies was also observed in Ladder and Archway. In conclusion, in-vitro studies were a powerful tool for characterizing and verifying ranibizumab release from the PDS implant and supported clinical evaluation of the PDS. PDS 100 mg/mL, which was associated with the longest therapeutic-level delivery of ranibizumab among the concentrations tested, was selected for evaluation in the pivotal phase III Archway trial.

Quantification of Titanium Release From Titanium Dioxide Impregnated Composites in Orthodontic Bonding—An In Vitro Study

Objective To evaluate the quantity of titanium dioxide nanoparticles released into the artificial salivary medium from orthodontic composite impregnated with 1% weight/weight (w/w) and 5% w/w titanium dioxide nanoparticles (TiO2 NPs) used for bonding metal brackets, thereby eventually comprehending the permissible levels. Materials and Method Eighty freshly extracted teeth for orthodontic treatment were divided into 2 groups of 40 teeth each and were bonded with brackets containing 1% w/w and 5% w/w composite containing titanium dioxide nanoparticles and placed in an artificial salivary medium. Quantification of 1% w/w and 5% w/w composite containing titanium nanoparticles was done using inductively coupled plasma mass spectroscopy for 4 timely periods 24 h, 2 months, 4 months, and 6 months. Results In the teeth that received 1% TiO2, the amount of titanium released was greatest in 2 months with no significant release at later intervals. In the second group that received 5%, there was a significant release of titanium at all intervals, with highest release at second month. On comparing the 2 concentrations at 4 different time intervals, the quantities were significantly greater in the 5% group at all time frames, thus implying a significant increase in titanium released with an increase in concentration from 1% to 5%. Conclusion Titanium release was higher in 5% w/w composite containing nanoparticles than 1% w/w composite containing nanoparticles, and 1% and 5% concentrations can be used safely and are within the permissible limits.

Effect of macrogeometry and bone type on insertion torque, primary stability, surface topography damage and titanium release of dental implants during surgical insertion into artificial bone

This study investigated the influence of implant macrogeometry and bone type on insertion torque (IT), primary stability (ISQ), surface topography damage, and the amount of titanium (Ti) released during insertion. Forty implants with different macrogeometries (Facility - Cylindrical with spiral-shaped threads; Alvim - Tapered with buttress-shaped threads) were inserted into artificial bone types I-II and III-IV. Surface morphology was evaluated by Scanning Electron Microscope (SEM) and roughness parameters with Laser Scanning Confocal Microscopy (LSCM) before and after insertion (AI). Implant macrogeometry was characterized by LSCM. The chemical composition of bone beds was determined by SEM associated with Energy Dispersive X-Ray Spectroscopy. The amount of Ti released was analyzed with Energy Dispersive X-Ray Fluorescence. Alvim had greater IT and ISQ than Facility. Bone types I-II require higher IT of implants. Alvim also had greater internal threads angle, higher initial roughness, and significant reduction of roughness AI, compared to Facility. The functional surface height reduced AI, especially in flank and valley of threads. Height of surface roughness of Alvim and Facility implants was similar AI. Implants surface morphology changes and metallic particles on bone beds were observed after implant insertion, mainly into bone types III-IV. Implants inserted into bone types I-II showed less surface damage. Alvim implants released more Ti (37.52 ± 25.03 ppm) than Facility (11.66 ± 28.55 ppm) on bone types III-IV. The implant macrogeometry and bone types affect IT, ISQ, surface damage, and Ti amount released during insertion. Alvim implants were more wear susceptible, releasing higher Ti concentration during insertion into bone types III-IV.

Evaluation of titanium release from titanium alloy implants in patients with spinal instrumentation.

ObjectiveThis study was performed to investigate the baseline serum titanium levels in patients with short-segment titanium alloy posterior instrumentation and to assess patient-, implant-, and surgery-related factors that might affect the serum titanium level.MethodTwo groups of patients were included in the study. The study group comprised 39 patients who had undergone short-segment posterior instrumentation from January 2013 to June 2016. The control group comprised 11 randomly selected patients who presented to the outpatient clinic with no history of orthopedic surgery. The serum titanium levels and inter-group differences were analyzed.ResultsThe mean serum titanium level was significantly higher in the study group than in the control group. No significant difference was observed between patients with different etiologies, implants used for fusion, numbers of instrumented segments, or postoperative durations.ConclusionThe serum titanium levels of patients with posterior lumbar spinal instrumentation are significantly higher than those of the normal population even after achievement of solid fusion. These levels are not affected by the use of transverse connectors, the use of cages, the operated segments, or the duration of implants.

Preclinical In Vitro Assessment of Submicron-Scale Laser Surface Texturing on Ti6Al4V.

Loosening of orthodontic and orthopedic implants is a critical and common clinical problem. To minimize the numbers of revision surgeries due to peri-implant inflammation or insufficient osseointegration, developments of new implant manufacturing strategies are indicated. Ultrafast laser surface texturing is a promising contact-free technology to modify the physicochemical properties of surfaces toward an anti-infectious functionalization. This work aims to texture Ti6Al4V surfaces with ultraviolet (UV) and green (GR) radiation for the manufacturing of laser-induced periodic surface structures (LIPSS). The assessment of these surface modifications addresses key aspects of topography, morphology and chemical composition. Human primary mesenchymal stromal cells (hMSCs) were cultured on laser-textured and polished Ti6Al4V to characterize the surfaces in terms of their in vitro biocompatibility, cytotoxicity, and metal release. The outcomes of the in vitro experiment show the successful culture of hMSCs on textured Ti6Al4V surfaces developed within this work. Cells cultured on LIPSS surfaces were not compromised in terms of their viability if compared to polished surfaces. Yet, the hMSC culture on UV-LIPSS show significantly lower lactate dehydrogenase and titanium release into the supernatant compared to polished. Thus, the presented surface modification can be a promising approach for future applications in orthodontics and orthopedics.

Evaluation of Titanium Serum Levels in Patients After Spine Instrumentation: Comparison Between Posterolateral and 360º Spinal Fusion Surgery.

IntroductionThe use of orthopedic implants is a cause for concern for the release of its integrating metals and the systemic complications that may occur. Instrumented spine arthrodesis is the recommended treatment for many spine diseases. Different segmental fixation devices, commonly made of titanium and its alloys, are used in these surgeries. The use of this metal for spinal fusion has introduced the possibility of generating microscopic metal particles that are present in the tissues of the surrounding implants (peri-implant environment). In fact, metal debris has been found in the paraspinal soft tissues of patients with posterior lumbar instrumentation and showed to be particularly high in patients undergoing revision procedures of pseudoarthrosis. In addition, part of the metals might also dissolve (either from the released particles or directly from the implant surface) and circulate in the body fluids, accumulating (eventually) in remote organs.Material and methodsA prospective study was designed with patients who were to be operated by the pathology of the lumbar spine to perform a vertebral arthrodesis composed of a titanium alloy (n=32). Two subgroups were differentiated according to the type of surgery performed: a) Posterolateral arthrodesis (N=5); b) Circumferential arthrodesis intervertebral implant of polyester-ether ketone (PEEK) (N=8) or titanium (N=19). The blood sample was taken before surgery and one year later. The samples were analyzed by mass spectrophotometry with a double focus inductive coupling plasma source (DF-ICP-MS).ResultsBlood titanium levels prior to surgery were similar to those in other publications (0.7449 micrograms per liter-1 (µgL-1), Standard Deviation (SD)=0.562). The average titanium concentration levels found after surgery was 2.5406 µgL-1 (SD=3,69), near 3.5-fold increase. After surgery, there was a significant mean increase in serum titanium levels of 1.7957 µgL-1 (SD=3.5765, Range=-0.57 µgL-1; 14.60 µgL-1). There is a statistically significant increment (p=0.00049) of the titanium concentration in the serum of the patients after surgery. If we analyze the patients in three groups according to the type of implants used (posterolateral, circumferential with PEEK, and circumferential with titanium), there are no differences between those who did not have an intersomatic device implanted and those in which PEEK implants were implanted, but with those in which it was titanium it was p=0.006 and p=0.018, respectively.ConclusionsPatients undergoing vertebral instrumentation experience a significant increase in serum titanium levels compared to before surgery levels. The use of an intersomatic device did not show differences in titanium release with not using it when it was PEEK. There are significant differences between patients without intersomatic implants or those who had a PEEK implant with those in whom it was titanium, with a significant increase in blood titanium levels.

Serum Nickel and Titanium Levels after Transcatheter Closure of Atrial Septal Defects with Amplatzer Septal Occluder.

Introduction There is a concern about release of nickel and titanium after implantation of nitinol-containing devices. Objective To evaluate serum nickel and titanium release after implantation of Amplatzer occluder. Materials and methods In 38 pediatric patients with no history of nickel sensitivity, blood samples were drawn 24 hours before and 24 hours, 1, 3, 6, and 12 months after implantation. Nickel and titanium concentrations were measured by atomic absorption spectrophotometry. Results The median serum nickel level which was 0.44 ng/mL before the implantation increased to 1.01 ng/mL 24 hours after implantation and 1.72 ng/mL one month after implantation. The maximum level was detected 3 months after implantation, with a median level of 1.96 ng/mL. During follow-up, the nickel levels decreased to those measured before implantation. Serum nickel levels at the 24th hour, 1st month, and 3rd month following implantation were found to have increased significantly. No patients showed a detectable serum titanium level. Discussion This is the first study that evaluated both serum nickel and titanium release after implantation of the Amplatzer occluder. Our study shows that nickel is released from the device in the first few months after implantation. Therefore, in patients with nickel allergy, other devices may be considered.

The role of citrate, lactate and transferrin in determining titanium release from surgical devices into human serum.

The presence of ionic titanium in the serum of patients with titanium implants is currently unexplained. This is presumed due to corrosion, and yet the serum titanium concentration measured in patients is far greater than that predicted by its solubility. The binding of titanium ion as Ti(IV) to human transferrin (hTF) in serum indicates that Ti(IV) ions interact with human physiology. This is an intriguing finding since there is currently no known role for titanium ions in human physiology. Thus, understanding the factors that determine in vivo titanium ion release is relevant to further understanding this metal's interactions with human biochemistry. The present study sought to determine the extent of titanium ion release of into human serum in vitro, and the role of citrate, lactate and hTF in this process. It was found that, when surgical devices of commercially pure titanium were placed into human serum, citrate and lactate concentrations were the prime determinants of titanium release. Crystallography revealed Ti(IV) bound to hTF in the presence of citrate alone, signalling that citrate can act as an independent ligand for Ti(IV) binding to hTF. Based on these findings, a two-stage process of titanium ion release into human serum that is dependent upon both citrate and hTF is proposed to explain the ongoing presence of titanium ion in human subjects with implanted titanium devices.

Corrosion behavior of titanium in response to sulfides produced by Porphyromonas gingivalis

ObjectiveTo investigate the effects of sulfides produced by Porphyromonas gingivalis (P. gingivalis) on the corrosion behavior of titanium. MethodsCommercially pure titanium disks were mirror-polished and immersed in culture medium (BHI), spent medium after culturing P. gingivalis (BHI-S), and culture medium with P. gingivalis (BHI-P), and incubated aerobically at 37°C for 3–14 days. Titanium corrosion was evaluated through surface observation (using scanning electron microscope: SEM), color change (ΔE*ab), glossiness (Gs(20°)), chemical composition and state (using X-ray photoelectron spectroscopy: XPS), and titanium release. ResultsΔE*ab and Gs(20°) did not significantly differ among specimens placed in test mediums for the study duration (p>0.05). SEM images of specimens showed no signs of localized or overall corrosion. XPS analysis indicated showed clear titanium metal state peaks on all specimens in addition to sulfide and sulfate on BHI-S and BHI-P specimens. Valency fraction of titanium decomposed from Ti2p spectrum of BHI-S and BHI-P specimens indicated no progression of oxidation. No significant levels of titanium release were found regardless of the mediums’ sulfide content. Results suggested that sulfides produced by P. gingivalis attached on the surface of titanium specimens but did not cause titanium corrosion over the immersion period of 14 days. SignificanceIt is imperative for dental practitioners to be aware of any elements which may influence the clinical success of titanium implants.

Influence of sulfide concentration on the corrosion behavior of titanium in a simulated oral environment

This study assessed the corrosion behavior of titanium in response to sulfide by determining the effects of sulfide concentration and pH over immersion period. Corrosion was evaluated through changes in color, glossiness, surface characterization, and titanium release. Sulfide solutions were prepared in 3 different concentrations with Na2S, each in pH unadjusted (sulfide-alkaline) and pH adjusted to 7.5 (sulfide-neutral). Titanium discoloration increased and glossiness decreased as sulfide concentration and immersion period increased in sulfide-alkaline solutions. Coral-like complexes were observed on the surface of these specimens, which became more pronounced as concentration increased. Small amounts of titanium release were detected in sulfide-alkaline solutions; however, this was not affected by immersion periods. Corrosion was indicated through considerable surface oxidation suggesting the formation of a thick oxide layer. No significant changes in color and glossiness, or titanium release were indicated for titanium specimens immersed in sulfide-neutral solutions indicating that pH had a significant effect on corrosion. Our findings suggest that a thick oxide layer on the titanium surface was formed in sulfide-alkaline solutions due to excessive oxidation.

Interruption of Electrical Conductivity of Titanium Dental Implants Suggests a Path Towards Elimination Of Corrosion.

Peri-implantitis is an inflammatory disease that results in the destruction of soft tissue and bone around the implant. Titanium implant corrosion has been attributed to the implant failure and cytotoxic effects to the alveolar bone. We have documented the extent of titanium release into surrounding plaque in patients with and without peri-implantitis. An in vitro model was designed to represent the actual environment of an implant in a patient’s mouth. The model uses actual oral microbiota from a volunteer, allows monitoring electrochemical processes generated by biofilms growing on implants and permits control of biocorrosion electrical current. As determined by next generation DNA sequencing, microbial compositions in experiments with the in vitro model were comparable with the compositions found in patients with implants. It was determined that the electrical conductivity of titanium implants was the key factor responsible for the biocorrosion process. The interruption of the biocorrosion current resulted in a 4–5 fold reduction of corrosion. We propose a new design of dental implant that combines titanium in zero oxidation state for osseointegration and strength, interlaid with a nonconductive ceramic. In addition, we propose electrotherapy for manipulation of microbial biofilms and to induce bone healing in peri-implantitis patients.

Titanium release in serum of patients with different bone fixation implants and its interaction with serum biomolecules at physiological levels

Increased concentrations of circulating metal-degradation products derived from the use of Ti orthopaedic implants may have deleterious biological effects over the long term. Therefore, there is an increasing need to establish the basal level of Ti in the serum of the population (exposed and non-exposed) with appropriate highly sensitive techniques and strategies. With this aim, we have developed a quantitative strategy for the determination of total Ti concentration in human serum samples by isotope dilution analysis using a double-focussing inductively coupled plasma mass spectrometer. Minimizing sample handling and therefore contamination issues, we obtained detection limits of about 0.05 μg L(-1) Ti working at medium resolution (m/Δm 4000). Such extremely good sensitivity permitted us to establish the range of Ti concentration in serum of 40 control individuals (mean 0.26 μg L(-1)) and also to compare it with the level in exposed patients with different Ti metal implants. On the other hand, Ti transport "in vivo" studies have been enabled by online coupling of liquid chromatography (anion-exchange) separation and double-focussing inductively coupled plasma mass spectrometry for sensitive detection of Ti. The development of a postcolumn isotope dilution strategy permitted quantitative characterization of the Ti-transporting biomolecules in human serum. The results for unspiked serum revealed that 99.8% of the Ti present in this fluid is bound to the protein transferrin, with column recoveries greater than 95%.

Titanium allergy: could it affect dental implant integration?

Degradation products of metallic biomaterials including titanium may result in metal hypersensitivity reaction. Hypersensitivity to biomaterials is often described in terms of vague pain, skin rashes, fatigue and malaise and in some cases implant loss. Recently, titanium hypersensitivity has been suggested as one of the factors responsible for implant failure. Although titanium hypersensitivity is a growing concern, epidemiological data on incidence of titanium-related allergic reactions are still lacking. A computer search of electronic databases primarily MEDLINE and PUBMED was performed with the following key words: 'titanium hypersensitivity', 'titanium allergy', 'titanium release' without any language restriction. Manual searches of the bibliographies of all the retrieved articles were also performed. In addition, a complementary hand search was also conducted to identify recent articles and case reports. Most of the literature comprised case reports and prospective in vivo/in vitro trials. One hundred and twenty-seven publications were selected for full text reading. The bulk of the literature originated from the orthopaedic discipline, reporting wear debris following knee/hip arthroplasties. The rest comprised osteosynthesis (plates/screws), oral implant/dental materials, dermatology/cardiac-pacemaker, pathology/cancer, biomaterials and general reports. This review of the literature indicates that titanium can induce hypersensitivity in susceptible patients and could play a critical role in implant failure. Furthermore, this review supports the need for long-term clinical and radiographic follow-up of all implant patients who are sensitive to metals. At present, we know little about titanium hypersensitivity, but it cannot be excluded as a reason for implant failure.

Calcium and titanium release in simulated body fluid from plasma electrolytically oxidized titanium

The release of titanium and calcium species to a simulated body fluid (SBF) at 37 degrees C has been investigated for titanium treated by dc plasma electrolytic oxidation (PEO) in three different electrolytes, namely phosphate, silicate and calcium- and phosphorus-containing. The average rate of release of titanium over a 30 day period in immersion tests, determined by solution analysis, was in the range approximately 1.5-2.0 pg cm(-2) s(-1). Calcium was released at an average rate of approximately 11 pg cm(-2) s(-1). The passive current densities, determined from potentiodynamic polarization measurements, suggested titanium losses of a similar order to those determined from immersion tests. However, the possibility of film formation does not allow for discrimination between the metal releases due to electrochemical oxidation of titanium and chemical dissolution of the coating.