In vitro biocompatibility of new bioactive lithia-silica glass-ceramics
Glass-ceramics based on the Li2O-SiO2 system have been extensively used as restorative dental materials due to their excellent chemical durability, aesthetics, inertness in the buccal environment, and high fracture strength; but they are not bioactive. On the other hand, all known bioactive glasses show ability to bond to bone, teeth and cartilage coupled to osteoconduction and osteoinduction, but their fracture strength and toughness are rather low. The aim of this study is to develop and evaluate the in vitro biocompatibility of a new type of (bioactive and strong) lithia-silica glass-ceramic.
New sintered wollastonite glass-ceramic for biomedical applications
We developed a new bioactive glass-ceramic (GC) based on the CaO-SiO2-MgO-Na2O-Li2O system. Four glass compositions were formulated by a proprietary software (Reformix) and tested by changing mainly the calcium content (from 20 mol% to 40 mol%) and the minor components - alumina, zirconia and zinc oxide. We produced our GCs using the sinter-crystallization process at different temperatures (800–1000 °C) and evaluated the effects of compositional changes on the sintering kinetics, microstructure (residual porosity and crystalline phases), hardness, bending strength and bioactivity.
Bioactivity and cytotoxicity of glass and glass–ceramics based on the 3CaO.P2O5–SiO2–MgO system
The mechanical strength of bioactive glasses can be improved by controlled crystallization, turning its use as bulk bone implants viable. However, crystallization may affect the bioactivity of the material. The aim of this study was to develop glass–ceramics of the nominal composition (wt%) 52.75(3CaO.P2O5)–30SiO2–17.25MgO, with different crystallized fractions and to evaluate their in vitro cytotoxicity and bioactivity.
The In Vitro Bioactivity, Degradation, and Cytotoxicity of Polymer-Derived Wollastonite-Diopside Glass-Ceramics
Ca-Mg silicates are receiving a growing interest in the field of bioceramics. In a previous study, wollastonite-diopside (WD) glass-ceramics were successfully prepared by a new processing route, consisting of the heat treatment of a silicone resin embedding reactive oxide particles and a Ca/Mg-rich glass. The in vitro degradation, bioactivity, and cell response of these new WD glass-ceramics, fired at 900–1100 °C for 1 h, as a function of the Ca/Mg-rich glass content, are the aim of this investigation
Mechanical properties and cytotoxicity of 3Y-TZP bioceramics reinforced with Al2O3 particles
The influence of Al2O3 addition and sintering parameters on the mechanical properties and cytotoxicity of tetragonal ZrO2–3 mol% Y2O3 ceramics was evaluated. Samples containing 0, 10, 20 and 30 wt.% of Al2O3 particles were prepared by cold uniaxial pressing (80 MPa) and sintered in air at 1500, 1550 and 1600 °C for 120 min. The effects of the sintering conditions on the microstructure were analyzed by X-ray diffraction analysis and scanning electron microscopy. Hardness and fracture toughness were determined by the Vickers indentation method and the mechanical resistance by four-point bending tests. As a preliminary biological evaluation, ‘‘in vitro’’ cytotoxicity tests were realized to determine the cytotoxic level of the ZrO2–Al2O3 composites, using the neutral red uptake method with NCTC clones L929 from the American Type Culture Collection (ATCC) bank
Effect of partial crystallization on the mechanical properties and cytotoxicity of bioactive glass from the 3CaO.P2O5–SiO2–MgO system
The aim of this study is to report on the development and characterization of bioactive glass and glass-ceramics from the 3CaO.P2O5-SiO2-MgO-system,using different degrees of cristallinity for applications as an implant material. A methodology was proposed to induce crystallization of phases. Bioglass samples of the nominal composition (wt%) 57.75CaO.P2O5–30 SiO2–17.25MgO were heat treated at temperatures ranging from 700 to 1100 °C for 4h. The findings from the research illustrate how partial crystallization and phase transformations modified the microstructure of the based glassy material, resulting in improved mechanical properties.