Synthetic hydroxyapatite (HA) whiskers have been utilized as a new, biocompatible reinforcement for orthopedic biomaterials. High-density polyethylene (HDPE) was reinforced with either the synthesized HA whiskers or a commercially available spherical HA powder using a novel powder processing technique that facilitated uniform dispersion of the reinforcements in the matrix prior to compression m...

This paper investigates some mechanical and rheological properties of low density polyethylene (LDPE) composites reinforced by multi-walled carbon nanotubes (MWNTs). It was found that the Young’s modulus and tensile strength of the composites can increase by 89% and 56%, respectively, when the nanotube loading reaches 10 wt%. The curving and coiling of MWNTs play an important role in the enhanc...

A multi-scale method to predict the stiffness and stability properties of carbon nanotube-reinforced laminates has been developed. This method is used in the prediction of the buckling behavior of laminated carbon nanotube-polyethylene composites formed by stacking layers of carbon nanotube-reinforced polymer with the nanotube alignment axes of each layer oriented in different directions. Linki...

The objective of this study was to examine the effects of the hydroxyapatite (HA) reinforcement morphology and content on the fatigue behavior of HA reinforced high density polyethylene (HDPE). To this end, HDPE was reinforced with 20 and 40 vol% of either HA whiskers or an equiaxed HA powder, and tested in four-point bending fatigue under simulated physiological conditions. The fatigue life, m...

The use ofcarbon fibre implants in orthopaedics is widely reported, but the potential risks associated with their use are less well defined. In its pure form carbon fibre may be spun into ligament and tendon replacements. Incorporated into epoxy resin, it has been used in plates for the internal fixation of fractures. Carbon fibre has also been used to reinforce polyethylene composites for join...

BACKGROUND Relapse following orthodontic treatment is a constant concern of orthodontists. Fixed retention is preferred especially for the lower arch by most orthodontists. OBJECTIVES This review focuses on in vivo studies. The main objective is to determine the survival rates of different types of retainer: glass-fiber reinforced composite resin, polyethylene or multistrand stainless steel w...

A composite hip prosthesis (CHP) made from alumina reinforced ultra high molecular weight polyethylene (UHMWPE) was designed and manufactured. The main objective of the study was to fabricate the composite hip prosthesis which would be an ideal replacement of metallic one as bone is a composite material consisting of collagen fibre matrix and embedded hydroxyapatite mineral. With this idea we d...

In order to investigate the mechanical properties of particulate reinforced polyethylene when using rotational moulding process, different mathematical models are used to predict the tensile properties. A series of micro-sized particles at various volume fractions are used as fillers for Liner MediumDensity Polyethylene (LMDPE) to verify those theoretical models. A comparison with the experimen...