INTRODUCTION Highly crosslinked polyethylenes were introduced for hip arthroplasty more than 10 years ago [1]. The creation of highly crosslinked polyethylenes involves irradiation of the material followed by annealing or remelting. Higher doses of irradiation are desirable because it provides a sufficient level of cross-linking for wear reduction, which is why highly crosslinked polythethylene...

The elastic moduli of polymer-carbon nanotube composites are examined by molecular dynamics simulations of a single-walled carbon nanotube embedded in polyethylene. The overall system is modeled with a many-body bond order potential due to Brenner. Alternatively, only the carbon nanotube is modeled with Brenner’s potential and the polyethylene matrix is modeled by a united-atom potential. For t...

A dual mobility acetabular component has a structure that combines a polyethylene liner and a femoral head, unlike the general design of acetabular cups, making the dissociation of a polyethylene liner highly unlikely. In addition, it increases the range of motion and reduces the possibility of dislocations by increasing a jump distance. A fifty-one-year-old male who had received total hip arth...

Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty. Submicron particles, which are secondary to abrasive wear, migrate into the effective joint space and stimulate a foreign-body response resulting in bone loss which is mainly mediated by macrophages. Diagnosis depends on serial radiographic evaluation and frequent follow-up. Polyethylene wear and osteo...

Polyethylene glycol dinitrates (PEGN) with molecular weights between 400 and 20 000 g·mol-1 were prepared from polyethylene glycols by esterification with nitric acid/sulfuric acid in dichloromethane. The products were characterized by gel permeation chromatography. The yield of PEGN increases with increasing reaction temperature (0-40 °C) however large liberation of nitrogen oxides was observe...

Linear alkyl ethoxylates (polyethylene glycol alkyl ethers) were fermented completely to methane and CO2 in enrichment cultures inoculated with anoxic sewage sludge. Long-chain fatty acids were released as intermediates. No degradation was found with polypropylene glycol and polypropylene glycol-containing surfactants. Two types of primary ethoxylate-degrading bacteria were isolated and charact...

The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display-using a 3D optical scanner-wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee c...

PURPOSE The aim of this study was to evaluate the bone repair process in the maxillary sinus in monkeys treated with high-density porous polyethylene (Medpor) METHODS Four capuchin monkeys (Cebus apella) were submitted to bilateral horizontal osteotomies in the anterior wall of the maxillary sinus and divided into 2 groups: control group, left side with no implants, and porous polyethylene gr...

A retrieval analysis has been performed on 50 polyethylene inlays of cementless screw ring implants (Mecring, Mecron, Berlin, Germany) to investigate the failure mechanism of this specific open cup hip arthroplasty design that has shown a high clinical failure rate. Design-specific damage modes like rim creep, collar fatigue, and backside wear were assessed. Furthermore, the inlays were measure...

A new technique in which polyethylene glycol is added to double-antibody assays of lutropin and follitropin eliminates the need for an incubation period during the separatory phase. After the antigen-first-antibody equilibrium reaction, the second antibody and polyethylene glycol (30 g/L final dilution) are added, the tubes are immediately centrifuged, each supernate is aspirated, and the preci...