The Benefits of Cement Augmentation of Pedicle Screw Fixation Are Increased in Osteoporotic Bone: A Finite Element Analysis.

Study Design: Biomechanical study using a finite element model of a normal and osteoporotic lumbar vertebrae comparing resistance with axial pullout and bending forces on polymethylmethacrylate-augmented and non-augmented pedicle screws.

Objective: To compare the effect of cement augmentation of pedicle screw fixation in normal and osteoporotic bone with 2 different techniques of cement delivery.

Summary Of Background Data: Various clinical and biomechanical studies have addressed the benefits of cement augmentation of pedicle screws, but none have evaluated whether this effect is similar, magnified, or attenuated in osteoporotic bone compared with normal bone.

The Use of Finite Element Models to Assist Understanding and Treatment For Scoliosis: A Review Paper.

Introduction: Scoliosis is a complex spinal deformity whose etiology is still unknown, and its treatment presents many challenges. Finite element modeling (FEM) is one of the analytical techniques that has been used to elucidate the mechanism of scoliosis and the effects of various treatments.

Methods: A literature review on the application of FEM in scoliosis evaluation and treatment has been undertaken.

β-Peptide coatings by surface-initiated polymerization.

Homopolymers of β-lactams can be grown by surface-initiated polymerization. These surface-linked β-peptides are living polymers with the potential to be utilized as tunable, protease-resistant interfaces in multiphase structural composites where the characteristics of the interface influence bulk properties.

Oxidation of titanium, RGD peptide attachment, and matrix mineralization rat bone marrow stromal cells.

The aim of this study was to compare the efficacy of attachment of arginine-glycine-aspartic acid (RGD) peptide to titanium surfaces oxidized by different methods. Titanium surfaces were treated as follows: (1) treatment A: passivation in nitric acid, (2) treatment B: heated in air at 400 degrees C for 1 hour, (3) treatment C: immersed in 8.8 M H2O2/0.

Strength and fatigue of polyacid-modified restorative materials (compomers).

The purpose of this study was to compare the fatigue behavior of a hybrid composite, four compomers, and two viscous glass ionomers after short- and long-term soaking in distilled water. Bars with dimensions of 30 mm x 2 mm x 2 mm were formed in stainless steel molds, finished with 600 grit SiC, then soaked for either 24 h or one year, and tested in 3-point flexure at stressing rates between 0.001 and 2500 MPa s(-1).

Silane treatment effects on glass/resin interfacial shear strengths.

Objective: Methacrylic resin-based dental composites normally use a bifunctional silane coupling agent with an intermediary carbon connecting segment to provide the interfacial phase that holds together the organic polymer matrix with the reinforcing inorganic phase. In this study, fiber pull-out tests were used to measure the interfacial bond strength at the fiber-matrix interface.

Methods: Glass fibers (approximately 30 microm diameter, 8 x 10 (-2)m length, MoSci) were silanated using various concentrations (1, 5 and 10%) of either 3-methacryloxypropyl-trimethoxysilane (MPS) or glycidoxypropyltrimethoxy-silane (GPS) in acetone (99.

The role of adsorbed endotoxin in particle-induced stimulation of cytokine release.

Numerous in vitro models have demonstrated the capacity of wear particles to stimulate the release of soluble pro-inflammatory products with the ability to induce local bone resorption. Recent observations have demonstrated that binding of lipopolysaccharide (LPS) to particulate wear debris can significantly modulate the pattern of cell response in the in vitro models. These findings raise concerns over the possible role of LPS in the pathogenesis of aseptic loosening after total joint replacements, and also indicates the importance of controlling for possible confounding effects of LPS contamination in the in vitro models used to study the reactive nature of wear debris.

The role of surface functional groups in calcium phosphate nucleation on titanium foil: a self-assembled monolayer technique.

Surface functional groups play important roles in nucleating calcium phosphate deposition on surgical titanium implants. In this study, various functional groups were introduced onto the surface of commercially pure titanium foils using a self-assembled monolayer (SAM) technique. An organic silane, 7-oct-1-enyltrichlorosilane (OETS) was used and -OH, -PO4H2, -COOH groups were derived from its unsaturated double bond.