Reinforcement of hydroxyapatite by adding P2O5-CaO glasses with Na2O, K2O and MgO

Abstract

Commercial hydroxyapatite was reinforced by adding small amounts (2 and 4wt%) of P2Os-based glasses during its sintering process. The composites prepared had a chemical composition closely related to the mineral part of bone tissues in terms of trace elements usually detected, such as Na, K and Mg. X-ray diffraction analysis (XRD) showed that the glass reinforced-HA composites were composed of a HA matrix and variable amounts of tricalcium phosphate phase, depending on sintering temperature and glass composition. These composites were shown to have much higher biaxial bending strength than sintered HA, 107 MPa for Ha/2% of 35P=O5-35CaO-10Na20-10K20-10MgO glass composite and 28 MPa for sintered HA. The presence of J3-tricalcium phosphate in the microstructure of the composites is an important factor in the reinforcement process.

CaO–P2O5–Na2O-based sintering additives for hydroxyapatite (HAp) ceramics

“…It is proven that there is a substantial potential for improving mechanical properties of HAp by adding trace amounts of calcium oxide (CaO) based sintering additives [21,[27][28][29][30][31]. Lopes et al [27] studied the effect of glass (75 mol% P 2 O 5 and 25 mol% CaO) reinforcement on mechanical properties of HAp for two different wt% additions (2.5, 4.0).…”

“…Most of these studies were focused on addition of a secondary phase as sintering aid to improve densification [21][22][23][27][28][29][30][31][32]. The basic science behind such favorable behavior of ceramics in the presence of sintering aids may vary from system to system, and to understand this, each system necessitates in depth independent study.…”

Cell-induced response by tetracyclines on human bone marrow colonized hydroxyapatite and Bonelike®

“…Glass-reinforced HA with bioactive properties has been applied with success in medical and dental clinical applications aiming to regenerate the bone tissue [17,18]. Bonelike Ò is a registered and patented glass-reinforced HA with improved mechanical properties and enhanced bioactivity that result from the addition of CaO-P 2 O 5 -based glasses during the liquid phase sintering process of HA, leading to several ionic substitutions in the lattice that are responsible for the reduction of porosity and grain size [19,20]. Recently, it has been successfully applied in regenerative procedures aiming to restore bone structure and function in oral, maxillofacial and orthopedic procedures [21,22].…”

Adsorption and release studies of sodium ampicillin from hydroxyapatite and glass-reinforced hydroxyapatite composites

“…Recently, glass-reinforced hydroxyapatite (GR-HA) composites have been developed [10,11] and biologically characterised both under in vitro and in vivo conditions, using osteoblast-like cell cultures [12] and animal models [13,14], respectively, showing a clear biocompatibility and bioactivity [12].…”