| A/W bioactive is a system of CaO-MgO-SiO2-P2O5-CaF2. fluorapatite andβ-wollastonite crystals were uniformly distributed in the glass matrix like grains. with high mechanical strength and fracture toughness, it's one of the best bio-glass ceramics and to be combination with human bones fast and firmly. is by far the best glass-ceramic, one biological. Widely used in load-bearing bone substitute, prosthesis spine, chest, frontal bone defect repair and restoration. Commonly preparation of A/W glass-ceramic biological method is melting method, samples though this method prepared is non-porous bioactive glass, a small surface area. The porous biological materials have superior general of the biological activity, porous bioceramic materials has good biodegradation properties and bone conduction because there is a large number of pore structure which conducive to the growth of tissue. After the implantation of life, new bone around the material continuously infiltration to the internal of it, material has been dispersed, degradation and then the composition of them to be in line, materials were replaced by new bone final. Therefore, to further enhance the biological of A/W glass-ceramics, to prepared the porous A/W glass-ceramic wonld be study in this papers. To improve biological of the original A/W glass-ceramic materials we'll enhance the porosity of it, micro-structure of biological material increase in the aperture, so that human cells can grow into the material body, and the body more closely combine. The micro-structure and performance of this A/W glass-ceramic would be closer to the body's natural bone.Using Triethy phosphate, Ethyl Silicate; Tetraethyl Orthosilicate, Calcium nitrate tetrahydrate, magne sium nitrate, calcium fluoride as material, A/W bioactive glass-ceramic powder can be prepared by sol-gel method. And then add a pore-forming material used on the preparation of the A/W glass-ceramic for biological pore, establishing a reasonable heat treatment system to prepare the porous A / W glass-ceramics of biological. Simulation experiment in vitro to be used to examine biological activity of the porous A/W glass-ceramics. Through XRD, FTIR, SEM to analysis these samples. The results show that:(1) When the molar ratio of the main raw material for: Triethyl phosphate: Calcium nitrate: Magnesium nitrate: TEOS = 1:3.1:0.6:2.5, through Sol - gel method, and then after heat treatment system we could obtain A/W glass-ceramic samples which micro-crystalline structure is good.(2) The amount of distilled water and ethanol will affect the sol - gel process, when water and TEOS volume ratio of 6:00, the shortest form a gel; and with the using of ethanol is increased, the gel time also to be extended, so the amount of ethanol is enough as it can dissolved alkoxide.(3) When adding a dose of pore-20wt%, the existence of the pore size is 30um in these samples, and at the same time the apparent porosity is 45.5%, close to human bones, the natural body's porosity is about 40%, it can be seen that in the powder add amount about 20wt% of pore-forming material can prepared the biological materials sample which micro-structure closer to the human bone morphology.(4) Glass-ceramics prepared by sol-gel method was to be immersion in simulated body fluid, the surface of the material is carbonated hydroxyapatite, and there generates spherical particles in the porous of the material also. This is confirmed that porous A / W glass-ceramic's biological activity is better than A/W glass-ceramics. |
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