Titanium Levels Research Articles

Evaluation of polypropylene CSF low-bind collection tubes for trace metal contamination.

Due to the ability of metal ions to cross the blood-brain barrier, there has been interest in analyzing cerebrospinal fluid (CSF) for trace element concentrations to investigate possible correlations with neurodegenerative diseases. In this study, Sarstedt polypropylene CSF collection tubes were analyzed to determine the contamination levels of aluminum, titanium, chromium, manganese, cobalt, nickel, molybdenum, gadolinium, vanadium, arsenic, cadmium, mercury, lead, thallium, selenium, copper, zinc, and iron. Sarstedt polypropylene CSF collection tubes from 2 separate lots (n = 10 per lot) were filled with a 2 mL aliquot of a CSF pool with known element concentrations. After 24 hours of leaching at room temperature, all 18 elements were analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Results were subtracted from the initial pool concentration to determine contamination levels. No detectable contamination above the assay limit of detection was found in 11 analytes. Molybdenum and selenium contamination was measured in all tubes, and aluminum, titanium, manganese, thallium, and zinc had minimal levels of sporadic detectable contamination in 25% or fewer of the tubes tested. Sarstedt polypropylene CSF tubes are an acceptable collection tube for the analysis of most assessed metals in CSF.

Petrogenesis of the Dalaku’an Mafic–Ultramafic Intrusion in the East Kunlun, Xinjiang: Constraints from the Mineralogy of Amphiboles

The Dalaku’an mafic–ultramafic intrusion, located in the western segment of the East Kunlun, presents conducive conditions for the magmatic Cu-Ni sulfide deposits. According to the detailed petrographic observation, the amphiboles within distinct rock types were analyzed by EPMA analysis. The crystallization conditions, such as temperature, pressure, oxygen fugacity, and water content of the magma, were calculated to explore the genesis of the intrusion. The amphiboles were divided into three types: Amp-I, characterized by low silicon content but enrichment of aluminum, titanium, and alkali, predominantly comprising Tschermakitic hornblende and Magnesio-hornblende with mantle-derived traits; Amp-II, exhibiting elevated silicon content but diminished levels of aluminum, titanium, and alkali, primarily constituted of Magnesio-hornblende; whereas Amp-III manifests as Actinolitic hornblende, indicative of crustal origins. The calculated temperatures of amphiboles ranged between Amp-I (955–880) °C, Amp-II (852–774) °C, and Amp-III (761–760) °C; the pressures ranged between Amp-I (454–274) MPa, Amp-II (194–93) MPa, and Amp-III (101–84) MPa; the oxygen fugacities (△NNO) ranged between Amp-I (0.93–2.17), Amp-II (1.55–2.52), and Amp-III (1.89); and the water contents (H2Omelt) ranged from (6.69–8.67) to (5.90–7.32). The magma experienced multiple stages of crystallization and underwent complex magma evolution at different depths. The high oxygen fugacity and water content could be attributed to the subduction of the oceanic crust. The magma source of the Dalaku’an intrusion was metasomatized by fluids from subducting plates, thereby originating within a post-collision extension.

Excellent Results of Large-Diameter Ceramic-On-Ceramic Bearings in Total Hip Arthroplasty at Minimum Ten-Year Follow-Up

BackgroundThis study reports the minimum 10 years results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head ceramic-on-ceramic bearing. MethodsOf the 276 THAs included in this study, there were eleven deaths and 27 patients lost to follow up (11%) during the follow-up, leaving 237 (85%) hips available for review at a mean of 10.5 years (range, 10 to 12) postoperatively. Reoperations, implant revisions, adverse events, clinical outcomes, radiographic evaluation, and whole blood metal ion levels were assessed at the last follow-up. ResultsAfter a minimum of 10 years, implant survivorship was 98.7%. There were 3 revisions (1.3%): one for insufficient acetabular cup primary fixation, one traumatic periprosthetic acetabular fracture, and one probable deep chronic infection. No dislocation or ceramic implant fracture was observed. The mean University of California at Los Angeles activity score, Western Ontario and McMaster Universities Osteoarthritis Index score, and Forgotten Joint Score were 5.6 (2 to 10), 90.1 (9 to 100), and 79.2 (4 to 100), respectively. All patients (100%) were satisfied or very satisfied. Since implantation, 43% of patients reported hearing a squeaking noise from the prosthesis. But all patients who reported squeaking were satisfied with the surgery. The mean titanium level was 2.2 μg/L (1.1 to 5.6). No progressive radiolucent lines, osteolysis, or implant loosening signs were observed at the last radiographic evaluation. ConclusionsA large-diameter head ceramic-on-ceramic THA provides outstanding long-term (minimum 10 years) implant survivorship with unrestricted activity while avoiding implant impingement, liner fracture, and hip instability. Functional outcomes, satisfaction, and joint perception were excellent. Although the incidence of squeaking was high, it did not affect patient satisfaction or function. The systemic titanium levels were low, related to unavoidable passive corrosion of implant surfaces, and did not reveal any indirect signs of trunnionosis.

Comparative analysis of serum titanium level in patient with healthy dental implant and patients with peri-implantitis- A cross sectional prospective study

Objectives: Titanium dental implants can last for more than two decades in the oral environment. Corrosion of the implant surface can release metallic particles or ions into surrounding tissue. The metallic constituents like titanium in human blood serum have not been fully studied. The study compares titanium serum levels before and after dental implant placement and compares levels in patients with healthy implants and those with per-implantitis. Methods: The study comprised 2groups of Group 1 patient observing implant surgery and group 2 patients with diagnosed peri-implantitis. Each group comprised of 60 patients. Serum titanium level was measured from blood obtained from Group 1 at three different intervals (one month prior to implant surgery, 4th and 8th month after successful loading) and from Group 2 during the course of peri-implantitis by inductively coupled plasma–mass spectroscopy. The statistical analysis was done for the obtained data. Results: Analysis showed a raised level of serum titanium at 4th month of post implant placement (2.39 mg/dl) and in patient with peri-implantitis(2.94 mg/dl) and both levels are significantly differ (ANOVA test) from pre-surgical estimation of serum titanium level (1.79 mg/dl). Conclusions: Understanding the correlation between titanium corrosion and peri-implantitis is vital for enhancing the long-term success and safety of dental implants. Additional research is required to investigate these links and potential strategies to protect the well-being of implant patients.

Assessment of titanium and cobalt urinary release from dental implants by ICP-MS: A case-control study

IntroductionDental implants are medical devices designed to replace missing teeth. They are usually made of titanium and cobalt. The present study aimed to evaluate the systematic release of cobalt and titanium in patients with dental implants. Materials and methodsThe present case-control study was conducted in dentistry establishments of the region of Chlef and included 24 patients with dental implants (group P) and 24 control subjects (group C). Titanium and cobalt urinary evels were quantified using Inductively Coupled Plasma Mass Spectrometry. The Shapiro–Wilk and Mann-whitney statistical tests were performed using R software. ResultsAssessed levels ranged from 0.001 to 0.025 and 0.020–3.900 ug.g−1 of creatinine for titanium and cobalt respectively. No statistically significant differences in titanium and cobalt urinary concentrations were found between the Group P and C (p = 0.521 and p = 0.577 for titanium and cobalt respectively). No statistically significant difference in titanium urinary levels was found between the smokers and non-smokers (p = 0.137). However, a statistically significant difference in cobalt urinary levels was found between the smokers and non-smokers (p = 0.002). In addition, a statistically significant difference in titanium and cobalt urinary levels was found between the subjects with and without orthopaedic implant (p = 0.001). ConclusionThe results revealed that there was no significant release of titanium and cobalt through dental implants in the studied population. Further studies with multidisciplinary approach, long-term follow-up and larger sample are required to evaluate other metals release from dental and orthopaedic implants.

Metal Ion Release in Cancer Patients Following Megaprosthesis Salvage Surgery

BackgroundMegaprostheses contain many more modular components than conventional total hip and knee arthroplasty, which may lead to higher serum levels of metal ions. The aim of this study was to determine serum concentrations of titanium, chromium, and cobalt ions in cancer patients after limb salvage surgery with a megaprosthesis. MethodsA retrospective, descriptive cohort analysis consisting of patients who underwent cancer-related limb salvage surgery with a megaprosthesis at our hospital between 2010 and 2020 was conducted. Baseline and follow-up data were extracted from clinical and surgical records. Blood samples were prospectively obtained. Descriptive statistics were used for the analysis. ResultsA total of 71 patients underwent limb salvage surgery during the study period. Of these, 22 (10 women, 12 men) were included in the study. The mean age was 52 years (range, 21 to 80). Most cases (n = 16; 72.7%) involved the femur. Most patients (n = 14, 63.6%) underwent total knee megaprosthesis surgery. Implant revision surgery was required in 45% of cases (n = 10), with a mean interval of 4.32 years between the initial and revision surgeries. The mean follow-up time after revision surgery was 4.05 years. High levels of chromium were observed in 22.7% of patients (n = 5). High cobalt levels were found in 68.2% (n = 15) of patients, with toxic levels in 9.1% (n = 2). Titanium levels were high in 77.3% (n = 17) of cases and toxic in 22.7% (n = 5). Postoperative chemotherapy was significantly associated with titanium levels (P = .017). No correlation was observed between metal ion levels and time from primary or revision surgery or time from the first to revision surgery. ConclusionsThis study shows that cancer-related limb salvage surgery with megaprosthesis is associated with metal ion levels that exceed established safe thresholds. Compared to conventional hip arthroplasty, a higher proportion of the patients in this cohort presented elevated levels of metal ions. Level of evidenceIII.

Metal artifact reduction sequence-MRI abnormalities in asymptomatic patients with dual-mobility hip prostheses.

Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations. A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years' follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels. Overall, two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels > 3.0 μg/l. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels < 1.0 μg/l. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels < 1.0 μg/l, while one (2.6%) had a cobalt level of 1.4 μg/l. One patient (2.2%) had a chromium level > 3.0 μg/l and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels > 5.0 μg/l without associated MARS-MRI abnormalities. Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic DM articulations occur infrequently (4.4%), but further assessment is necessary due to implant heterogeneity.

The size of the femoral head does not influence metal ion levels after metal-on-polyethylene total hip arthroplasty: a five-year report from a randomized controlled trial.

In metal-on-polyethylene (MoP) total hip arthroplasty (THA), large metal femoral heads have been used to increase stability and reduce the risk of dislocation. The increased size of the femoral head can, however, lead to increased taper corrosion, with the release of metal ions and adverse reactions. The aim of this study was to investigate the relationship between the size of the femoral head and the levels of metal ions in the blood in these patients. A total of 96 patients were enrolled at two centres and randomized to undergo MoP THA using either a 32 mm metal head or a femoral head of between 36 mm and 44 mm in size, being the largest possible to fit the thinnest available polyethylene insert. The levels of metal ions and patient-reported outcome measures (Oxford Hip Score, University of California, Los Angeles Activity Scale) were recorded at two and five years postoperatively. At five years, the median levels of chromium, cobalt, and titanium were 0.5 μg/l (interquartile range (IQR) 0.50 to 0.62), 0.24 μg/l (IQR 0.18 to 0.30), and 1.16 μg/l (IQR 1.0 to 1.68) for the 32 mm group, and 0.5 μg/l (IQR 0.5 to 0.54), 0.23 μg/l (IQR 0.17 to 0.39), and 1.30 μg/l (IQR 1 to 2.05) for the 36 mm to 44 mm group, with no significant difference between the groups (p = 0.825, p = 1.000, p = 0.558). There were increased levels of metal ions at two years postoperatively in seven patients in the 32 mm group, compared with four in the 36 mm to 44 mm group, and at five years postoperatively in six patients in the 32 mm group, compared with seven in the 36 mm to 44 mm group. There was no significant difference in either the OHS (p = 0.665) or UCLA (p = 0.831) scores between patients with or without an increased level of metal ions. In patients who underwent MoP THA, we found no differences in the levels of metal ions five years postoperatively between those with a femoral head of 32 mm and those with a femoral head of between 36 mm and 44 mm, and no corrosion-related revisions. As taper corrosion can start after five years, there remains a need for longer-term studies investigating the relationship between the size of the femoral head size and corrosion in patients undergoing MoP THA.

Comparative analysis of serum titanium levels in patients with healthy dental implants and patients with peri‑implantitis: A cross sectional prospective study

Comparative analysis of serum titanium levels in patients with healthy dental implants and patients with peri‑implantitis: A cross sectional prospective study

Pre and post-operative serum levels of titanium cobalt and aluminium after implant placement.

The preoperative serum levels and postoperative serum levels of titanium, cobalt and aluminium from dental implants in order to assess the release of these ions and to assess any risk of toxicity from these ions after dental implant placement is of interest to dentists. It was observed that there was very slight increase in serum concentration of titanium, cobalt and aluminium after 12 months of placement of implants as compared to before placement of implants. However the increase was non-significant statistically. Our study concluded that the use of dental implants does not pose any risk of toxicity of metal ions like titanium, aluminium and cobalt because of very slight non-significant increase in serum levels of these ions 12 months after implant placement.

Evaluation of the cytotoxic effect of titanium dioxide nanoparticles in human embryonic lung cells.

Titanium dioxide nanoparticles are widely used in a variety of products, including sunscreens, paints, and ceramics. However, their increasing use has raised concerns about their potential health risks. Titanium dioxide nanoparticles have been shown to have the ability to enter the bloodstream and accumulate in various tissues, reaching the fetus via the placenta. The aim of this study was to investigate the cytotoxic effects of titanium dioxide nanoparticles on a human embryonic lung cell line (HEL 299/An1) and the formation of oxidative DNA damage. The cytotoxic effects of brookite-based titanium dioxide nanoparticles (<100 nm) were assessed using the 3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) assay for 24 and 48 h. Cell titanium levels were determined using inductively coupled plasma mass spectrometry. Oxidative DNA damage was assessed by measuring the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) as a biomarker. Titanium dioxide nanoparticles caused dose-dependent cytotoxicity in HEL 299/An1 cells. The IC50 values were 25.93 μM and 0.054 μM after 24 h and 48 h of exposure, respectively. Cell titanium levels were found to be 25,967 ppb after 24 h and 210,353 ppb after 48 h (p < 0.01). 8-OHdG was detected at 32.96 ng/mL after 24 h of exposure and 17.89 ng/mL after 48 h of exposure. In our study, it was shown that titanium nanoparticles caused dose-dependent cytotoxicity and oxidative DNA damage in human embryonic lung cells. The nanoparticles also accumulated in cells and were taken up in higher amounts after 48 h of exposure. These findings suggest that titanium dioxide nanoparticles may pose a health risk, especially for pregnant women who may not be aware of their pregnancy. Therefore, it is important to take preventive measures to reduce exposure to these nanoparticles.

Serum Titanium Levels Remain Elevated But Urine Titanium is Undetectable in Children With Early Onset Scoliosis Undergoing Growth-Friendly Surgical Treatment: A Prospective Study

Background: Elevated serum titanium levels have been found in patients with early onset scoliosis (EOS) treated with traditional growing rods (TGR), magnetically controlled growing rods (MCGR), and vertical expandable prosthetic titanium rib (VEPTR). No studies have investigated whether serum titanium remains persistently elevated and if titanium is excreted. Our purpose was to compare serum titanium levels in patients with EOS with growth-friendly instrumentation to age-matched controls and evaluate urine titanium and serial serum titanium levels in patients with EOS. Methods: This was a prospective case-control study. Patients with EOS with TGR, MCGR, or VEPTR underwent urine titanium and serial serum titanium collection at a minimum 6-month interval. Control patients did not have a history of metal implant insertion and underwent serum titanium collection before fracture fixation. Results: Twenty patients with EOS (6 TGR, 8 MCGR, and 6 VEPTR) and 12 controls were analyzed. The control group had no detectable serum titanium (0 ng/mL), whereas the patients with EOS had a median serum titanium of 4.0 ng/mL (P &lt; 0.001). Analysis of variance showed significantly higher median serum titanium levels in the MCGR and VEPTR groups than the TGR group at time point 1 (5.5 vs 6.0 vs 2.0 ng/mL, P = 0.01) and time point 2 (6.5 vs 7.5 vs 2.0 ng/mL, P &lt; 0.001). Binary comparisons showed a significant difference in serum titanium level between TGR and MCGR (time point 1: P = 0.026, time point 2: P = 0.011) and TGR and VEPTR (time point 1: P = 0.035, time point 2: P = 0.003). However, there was no difference between MCGR and VEPTR (time point 1: P = 0.399, time point 2: P = 0.492) even though the VEPTR group had a longer duration of follow-up (P = 0.001) and a greater number of lengthenings per patient at the first serum collection (P = 0.016). No patients with EOS had detectable urine titanium. Conclusions: Patients with EOS treated with titanium alloy growth-friendly instrumentation had elevated serum titanium levels compared with age-matched controls that persisted over time with no evidence of renal excretion. Additional studies are necessary to assess for local and systemic accumulation of titanium and the significance of long-term exposure to titanium in growing children. Level of Evidence: Level III, therapeutic.

The Evaluation of Serum Metal Ion Levels and Metallosis in Graduated Patients With Magnetically Controlled Growing Rods.

Magnetically controlled growing rods (MCGR) aim to control curve progression while limiting surgical burden in children with early-onset scoliosis. Systemic and local distribution of metal debris has been documented in children with spinal implants. The aim of the study was to assess serum metal ion levels and local metal debris-related changes at the conclusion of MCGR treatment. Between February 2019 and September 2022, all patients who had a conversion to definitive fusion at the completion of MCGR treatment in our institution were invited to participate in this study. Consenting patients had serum metal ion levels drawn (titanium, cobalt, and chromium) and histologic analyses of peri-implant tissue samples. We enrolled 24 children who underwent definitive fusion post-MCGR treatment for early-onset scoliosis. The average age at definitive fusion was 13.3 years (range: 11 to 17 y). The average length of MCGR treatment was 4.8 years (range: 1.5 to 6.8 y). At the end of the MCGR treatment, 23 (96%) patients had elevated serum metal ion levels. Mean serum titanium levels were 165.4 nmol/L (range: 30 to 390 nmol/L), mean serum cobalt levels were 4.6 nmol/L (range: 1.2 to 14 nmol/L), and mean serum chromium levels were 14 nmol/L (range: 2.4 to 30 nmol/L). Peri-implant soft tissue histologic analysis demonstrated local metal debris and foreign body reactions in all patients. At the completion of MCGR treatment, the majority of patients demonstrate elevated serum metal ion levels and local metal debris-related peri-implant soft tissue changes. Although there is no current literature to suggest these findings are harmful, further research as to the clinical significance is required. Level IV.

Estimation of Titanium Levels in Blood Following Reconstruction of Post-Craniotomy Defect by Titanium Mesh Using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES).

Titanium and its alloys are the most popular choice of materials for the reconstruction of craniofacial defects. They have lighter weight and are nonferromagnetic, which makes them an advantage in cranial defect reconstruction. Although the formed oxide layer makes them corrosion-resistant, levels of titanium in blood have been seen in trace amounts. This is the first study as per authors' knowledge that a study of such kind has been conducted. A pilot study was carried out at a tertiary level hospital, considering the inclusion and exclusion criteria in patients who were planned for the reconstruction of the residual defect using titanium mesh. Preoperative and 03- and 06-months postoperative blood samples were collected and analyzed for estimating the levels of titanium ions in blood by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Friedman's two-way analysis of variance by ranks was considered for testing of hypothesis summary, owing to the smaller sample size. The analysis suggested an increase in levels was minimal. Considering the asymptotic significances (two-tailed significance), a significance level was 0.050, which directed us to reject the null hypothesis. Pairwise comparison suggested the presence of negative values indicating steady increase in levels. Cluster analysis indicated that although minimal there is a cluster of difference in the values at all three stages. Continuous field information was used to determine the level with regard to the level of titanium at the three stages of study. The study revealed that the levels of titanium ions increase on prolonged contact with living tissues. The trace elements have to be analyzed at regular intervals. This first-of-the-time study if extended to larger sample size would reveal interesting facts.

Toxic element contaminations of prenatal vitamins

The detrimental effects of gestational and lactational exposure to adverse chemical agents are gathering increasing attention. In our study, the presence of toxic heavy metals in several prenatal vitamins from six brands available in supermarkets and pharmacies was measured using ICP mass spectrometry. Several toxic heavy metals were detected, some at levels that could have potential toxicity to the fetus and the mother as well. Previous studies have also detected toxic heavy metals in prenatal and other vitamins. One of the reasons for toxic heavy metals in “natural vitamins” sold to consumers is that they are produced from naturally grown material and not synthesized. They are likely exposed to the heavy metals from the ground that they are grown in and there has not been any significant attempt to get rid of them before the vitamin pill was sold to consumers. Thus, this problem is not an isolated issue and regulatory agencies should be dealing more aggressively than they have been doing. In fact, several papers have already been published showing similar findings as we are reporting here. The vitamin pills we analyzed have elevated levels of boron, aluminum, molybdenum, barium, lead, titanium, nickel, arsenic, strontium, and cadmium. The levels of total chromium were also elevated but we did not separately determine Cr(III) and the much more hazardous Cr(VI), because of the tedious procedure required to separate these two forms of Cr.

METAL ARTIFACT REDUCTION SEQUENCE MRI ABNORMALITIES IN ASYMPTOMATIC PATIENTS WITH DUAL MOBILITY HIP PROSTHESES

Modular dual mobility (DM) articulations are increasingly utilized during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) abnormalities with serum metal ion levels in patients with DM articulations.All patients with an asymptomatic, primary THA and DM articulation with &gt;2-year follow-up underwent MARS-MRI of the operative hip. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels.Forty-five patients (50 hips) with a modular DM articulation were included with average follow-up of 3.7±1.2 years. Two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels &gt;3.0 μg/L. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels &lt; 1.0 μg/L. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels &lt;1.0 μg/L, while one (2.6%) had a cobalt level of 1.4 μg/L. One patient (2.2%) had a chromium level &gt;3.0 μg/L and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels &gt;5.0 μg/L without associated MARS-MRI abnormalities.Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic dual mobility articulations occur infrequently (4.4%), but further assessment of these patients is necessary.Level of Evidence: Level IV

FEMORAL HEAD SIZE DOES NOT INFLUENCE METAL ION LEVELS AFTER METAL-ON-POLYETHYLENE TOTAL HIP ARTHROPLASTY: A FIVE-YEAR REPORT FROM A RANDOMIZED CONTROLLED TRIAL

In metal-on-polyethylene (MoP) THA large femoral metal heads are designed to increase stability and to reduce dislocation risk. The increased head size could lead to increased taper corrosion with the release of metal ions and adverse reactions. Using blood ion measurements, we aimed to investigate the association between femoral head size and metal-ion release after MoP THA.96 patients were enrolled at two centers and randomized to receive either a 32-mm metal head or a 36–44 mm metal head (the largest possible fitting the thinnest available polyethylene insert). Blood metal ions and PROMs (OHS, UCLA) were measured at two- and five-year follow-ups.Both 2- and 5-year median chrome, cobalt, and titanium levels were below taper corrosion indicative ion levels. At 5 years, median chrome, cobalt, and titanium levels were 0.5 μg/L (0.50–0.62), 0.24 μg/L (0.18–0.30), and 1.16 μg/L (1.0–1.68) for the 32-mm group, and 0.5 μg/L (0.5–0.54), 0.23 μg/L (0.17–0.39), and 1.30 μg/L (1–2.05) for the 36–44 mm group, with no difference between groups (p=0.825, p=1.000, p=0.558). At 2 years, 7 (32-mm) versus 4 (36–44-mm) patients had elevated ions. At 5 years, 6 (32-mm) versus 7 (36–44-mm) patients had elevated ions. There was no difference in either OHS (p=0.665) or UCLA (p=0.831) between patients with or without elevated blood metal ions.5 years after the insertion of MoP THAs, we found no differences in the blood metal ion levels between 32 mm heads and 36–44 mm heads and no corrosion-related revisions. As taper corrosion can debut after 5 years, there is still a need for long-term follow-up studies on the association between head size and corrosion in MoP THA.

Quantification of titanium and zirconium elements in oral mucosa around healthy dental implants: a case–control pilot study

ObjectivesMetallic particles are detected in different sites of the oral cavity, mainly in patients with peri-implantitis lesions. The aim of this pilot study was to analyze the levels of titanium and zirconium elements in the oral mucosa around healthy implants and to investigate the impact of titanium exogenous contamination on the measurements.Materials and MethodsForty-one participants were included in this three-phase study. Two groups of subjects were defined according to presence of titanium or zirconia implants (n: 20) or without any implants nor metallic restorations (n:21). Thirteen patients (n: 5 with zirconia implant; n: 3 with titanium implants; n: 5 control group) took part to the first part designed to optimize and validate the method of detecting titanium (Ti) and zirconium (Zr) elements in the oral mucosa and gingival tissues by the Inductively Coupled Plasma Mass Spectrometry (ICPMS). The second phase compared the levels of Ti and Zr concentrations in patients with implants (n: 12) and without implants (n: 6) who were controlled for their intake of titanium dioxide (TiO2). The last step included ten control subjects without any metallic devices to measure the concentration of Ti and Zr before and after having candies containing TiO2.ResultsIn the first phase, concentrations of Ti and Zr were below the limit of detection (LOD) in most cases, 0.18 μg/L and 0.07 μg/L respectively. In the titanium group, two out of three subjects displayed concentrations above the LOD, 0.21 μg/L and 0.66 μg/L. Zr element was only found in patients with zirconia implants. After controlling the intake of TiO2, all concentrations of Ti and Zr were below the limit of quantification (LOQ). Moreover, in patients with no implants, the Ti concentration in gingiva cells was superior for 75% of the samples after having a TiO2 diet.ConclusionsZirconium was only found in patients with zirconia implants, whereas titanium was detected in all groups even in subjects with no titanium implants. Zirconium and titanium elements were not detected in patients who were controlled for their intake of food and their use of toothpaste irrespective of the presence of implants or not. For 70% of the patients, the titanium detection was directly influenced by the intake of TiO2 contained candies.Clinical relevanceWhen analyzing titanium particles, it is necessary to pay attention to the risk of contamination bias brought by external products. When this parameter was controlled, no titanium particles were detected around clinically healthy implants.

Association Between Heavy Metals Exposure and Height in Chinese Preschoolers.

This study aimed to explore the association between multiple metals' exposure and children's height. We collected urine samples and physical measurement data of 1477 preschoolers in China. Children's actual height was measured, and whether reached target height was also assessed. Logistic regression analysis was performed to explore the association between heavy metals and height. The least absolute shrinkage and selection operator regression was used to select the urinary metals, which were highly correlated. In the single-metal model after adjusting for potential confounders, urinary iron, aluminum, nickel, chrome, titanium, vanadium, selenium, rubidium, and thallium levels were negatively associated with actual height. Urinary iron, aluminum, nickel, and chrome concentrations were also negatively associated with target height. The findings suggested that some urinary metal exposure might be associated with height in preschoolers.

Assessment of Metal Ions Levels in Blood of Dental Implant Patients.

Dental implants use has significantly increased and the concentration of metal ions into blood may have detrimental effect of human body. The present study aimed to determine metal ions levels in blood of dental implants patients. 48 patients scheduled for dental implant surgery was assessed for measurement of titanium and aluminum pre-operatively and post-operatively at 6 weeks, 3 months, 6 months, and 1 year. Out of 48 patients, males were 22 (45.8%), and females were 26 (54.2%). The mean ± SD titanium metal levels in blood pre-operatively was 2.34 ± 0.47 mg/dl, at 6 weeks was 2.35 ± 0.48 mg/dl, at 3 months was 2.37 ± 0.52 mg/dl, at 6 months was 2.37 ± 0.42 mg/dl, and at 1 year was 2.38 ± 0.51 mg/dl. A non-significant difference was seen (P > 0.05). The mean ± SD aluminum metal levels in blood pre-operatively was 4.4 ± 0.12 mg/dl, at 6 weeks was 4.45 ± 0.14 mg/dl, at 3 months was 4.7 ± 0.13 mg/dl, at 6 months was 4.7 ± 0.21 mg/dl, and at 1 year was 4.8 ± 0.17 mg/dl. A non-significant difference was seen (P > 0.05). A non- significant increase in titanium and aluminum ions level in blood of patients receiving dental implants was observed.