BACKGROUND Cement augmentation of pedicle screws increases fixation strength in an osteoporotic spine. This study was designed to determine the cement distribution and the correlation between the pull-out strength of the augmented screw and the cement volume within polyurethane (PU) foam. METHODS Twenty-eight cannulated pedicle screws (6×45 mm) (Peter Brehm, Erlangen, Germany) with four holes...

Nano-TiO2 (NT) and nano-SiO2 (NS) were separately added in the cement paste to investigate the rheological property of fresh mixtures and mechanical strength in hardened state. The effects of different dosages and types of nano-particles on the properties of cement paste were studied. The results indicated that the rheological behavior of the fresh cement paste coincides with the Modified Bingh...

Current concepts in cement Total Hip Arthroplasty advocates optimization of mechanical interlock of cement (PMMA) with trabecular bone. The Third generation cementing technique has been developed to achieve this with the use of cement gun retrograde cementing within the proximal femur and pressurization of the cement with wedge or surgeon’s thumb. The forces generated by cement compression duri...

To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO41...

Superplasticizers are a class of anionic polymer dispersants used to inhibit aggregation in hydraulic cement, lowering the yield stress of cement pastes to improve workability and reduce water requirements. The plant-derived biopolymer lignin is commonly used as a low-cost/low-performance plasticizer, but attempts to improve its effects on cement rheology through copolymerization with synthetic...

Construction of geothermal wells that are effectively cemented and durable poses a significant operational challenge. Typically, lost circulation while drilling and cementing can make it seemingly impossible to place a complete column of cement behind casing strings. Incomplete cementation can lead to well failure caused by cyclic temperature loading on the casing that occurs throughout the lif...

OBJECTIVE To study the results of implantation of preformed hydroxyapatite (HA) disks and HA cement in onlay augmentation. METHODS In this prospective study involving 16 adult New Zealand rabbits, HA disk and HA cement samples were implanted separately and together along the bony and cartilaginous nasal dorsum as well as over the supraorbital bone. Gross and histologic examinations of the imp...

Bone cement containing gentamicin may release antibiotic when fractured during revision operations. Tissue samples taken during surgery may be contaminated by gentamicin and give inaccurate microbiological assessment. We studied five patients in whom cement containing gentamicin had been used in the primary procedure. During revision hip replacement, samples of joint fluid, tissues and cement w...

Ordinary Portland Cement (OPC) is often used for the solidification/stabilization (S/S) of waste containing heavy metals and salts. These waste components will precipitate in the form of insoluble compounds on to unreacted cement clinker grains preventing further hydration. In this study the long term effects of the presence of contaminants in solidified waste is examined by numerically simulat...

The feasibility of calcium carbonate cements involving the recrystallisation of metastable calcium carbonate varieties has been demonstrated. Calcium carbonate cement compositions presented in this paper can be prepared straightforwardly by simply mixing water (liquid phase) with two calcium carbonate phases (solid phase) which can be easily obtained by precipitation. An original cement composi...