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Wear debris-induced inflammation is considered to be the main cause for periprosthetic osteolysis in total hip replacements (THR). The objective of this retrieval study was to examine the tissue reactions and exposure to metal ions and wear particles in periprosthetic tissues and blood samples from patients with titanium (Ti)-based hip prostheses that were revised due to wear, osteolysis, and/or aseptic loosening. Semiquantitative, histological tissue evaluations in 30 THR-patients revealed numerous wear debris-loaded macrophages, inflammatory cells, and necrosis in both groups. Particle load was highest in tissues adjacent to loosened cemented Ti stems that contained mainly submicron zirconium (Zr) dioxide particles. Particles containing pure Ti and Ti alloy elements were most abundant in tissues near retrieved uncemented cups. Polyethylene particles were also detected, but accounted only for a small portion of the total particle number. The blood concentrations of Ti and Zr were highly elevated in cases with high abrasive wear and osteolysis. Our findings indicate that wear particles of different chemical composition induced similar inflammatory responses, which suggests that particle size and load might be more important than the wear particle composition in periprosthetic inflammation and osteolysis. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B:709–717, 2015.

Results are reported from a study on the in vitro separation and identification of leachables from three different polymer-based dental filling materials by using a combined method of gas chromatography and mass spectrometry. The median number of separable organic leachables in these materials was between 14 and 22. Of these organic leachables the following were identified and quantified: DL-camphorquinone, 4-dimethylaminobenzoic acid ethyl ester (DMABEE), drometrizole, 1,7,7-trimethylbicyclo[2,2,1]heptane, 2,2-dimethoxy[1,2] diphenyletanone (DMBZ), ethyleneglycol dimethacrylate (EGDMA), and triethyleneglycol dimethacrylate (TEGDMA). Three of the leachables have previously been shown to provoke allergy. The range of log P(ow) values (representing the lipophilicity of these compounds) varied between 1.09 and 4.20. By multivariate data analysis, selected leachables from the tested materials were shown to separate into characteristic patterns. The results contribute to a characterization of potential hazardous compounds in polymer-based dental filling materials.

Background and purpose Despite the fact that there have been some reports on poor performance, titanium femoral stems intended for cemented fixation are still used at some centers in Europe. In this population-based registry study, we examined the results of the most frequently used cemented titanium stem in Norway.Patients and methods 11,876 cases implanted with the cemented Titan stem were identified for the period 1987–2008. Hybrid arthroplasties were excluded, leaving 10,108 cases for this study. Stem survival and the influence of age, sex, stem offset and size, and femoral head size were evaluated using Cox regression analyses. Questionnaires were sent to the hospitals to determine the surgical technique used.Results Male sex, high stem offset, and small stem size were found to be risk factors for stem revision, (adjusted RR = 2.5 (1.9–3.4), 3.3 (2.3–4.8), and 2.2 (1.4–3.5), respectively). Patients operated in the period 2001–2008 had an adjusted relative risk (RR) of 4.7 (95% CI: 3.0–7.4) for stem revision due to aseptic stem loosening compared to the period 1996–2000. Changes in broaching technique and cementing technique coincided with deterioration of the results in some hospitals.Interpretation The increased use of small stem sizes and high-offset stems could only explain the deterioration of results to a certain degree since the year 2000. The influence of discrete changes in surgical technique over time could not be fully evaluated in this registry study. We suggest that this cemented titanium stem should be abandoned. The results of similar implants should be carefully evaluated.

Pregnant women and infants are at risk for selenium deficiency, which is known to have negative effects on immune and brain function. We have investigated selenium levels in 158 healthy never-pregnant women and in 114 pregnant and lactating women and their infants at age 6 months and related this to clinical outcomes during the first 6 months of life. Neurodevelopment was assessed with the parental questionnaire Ages and Stages (ASQ) at 6 months. A maternal selenium level ≤0.90 µmol/L in pregnancy week 18 was negatively related to infant neurodevelopment at 6 months (B = −20, p = 0.01), whereas a selenium level ≤0.78 µmol/L in pregnancy week 36 was associated with an increased risk (odds ratio 4.8) of having an infant infection during the first 6 weeks of life. A low maternal selenium status in pregnancy was found to be associated with an increased risk of infant infection during the first 6 weeks of life and a lower psychomotor score at 6 months. We suggest a cutoff for maternal serum selenium deficiency of 0.90 µmol/L in pregnancy week 18 and 0.78 µmol/L in pregnancy week 36. This should be reevaluated in an intervention study.

The present study examines the quantity, size, element signatures and distribution of titanium particles in normal oral mucosal tissue and in oral mucosa exposed to a titanium implant. Tissue samples from six healthy patients were obtained by a full thickness biopsy taken from the edge of the oral mucosa when inserting a titanium dental implant. At the abutment insertion 6 months later, a punch test biopsy of oral mucosa was taken over the implant site. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is a sensitive and specific multi-element microanalytical technique that demonstrated the presence of Ti particles in the tissue adjacent to implant cover-screws. The epithelial part of the control samples revealed more particles than the corresponding area of the test samples, consisting partly of newly formed scar tissue. High-Resolution Optical Darkfield Microscope (HR-ODM) confirmed the presence of particles in both the control and the test samples. The combination of LA-ICP-MS and HR-ODM appears to be a powerful combination for detection of particles in oral tissues; optical microscopy provides an overview with histological references, whereas LA-ICP-MS identifies the chemical composition.