7th International Congress on Ceramics

Synthesis and characterization of bioactive ceramic in CaO-MgO-SiO2 system

Reference	Presenter	Authors (Institution)	Abstract
02-025	Daniel de Rezende Leme	Leme, D.d.(Instituto de Pesquisas Energéticas e Nucleares); Morais, V.R.(Instituto de Pesquisas Energéticas e Nucleares); Rodas, A.C.(Universidade Federal do ABC, Santo André, (SP), BRAZIL); Higa, O.Z.(Instituto de Pesquisas Energéticas e Necleares); Yamagata, C.(Instituto de Pesquisas Energéticas e Nucleares);	Since the discovery of 45S5 glass-ceramic $b i o g l a s s^{®}$ by Larry Hench in 1969, this material has been studied because of its bioactivity. Among various ceramic materials for orthopedic applications that have been developed recently, the $C a O - M g O - S i O_{2}$ system glass-ceramic received attention because the presence of $M g^{2 +}$ that improves mechanical properties of the material as well as osseointegration in living tissue. In this work, sodium silicate solution, as silica source, and hydrochloric solutions of calcium and magnesium were used as raw materials. Hydrochloric acid was added to sodium silicate solution resulting in gel of silica through acid catalysis reaction. In order to obtain a mixture of Si gel, $C a^{2 +}$ and $M g^{2 +}$ , calcium and magnesium solutions were blended into the gel. After adding NaOH to the mixture, $C a^{2 +}$ and $M g^{2 +}$ ions precipitated as hydroxides. Then, the resulted product was filtered and washed with deionized water until no $C l^{-}$ ion was detected. Subsequently, it was dried to attain the ceramic precursor powder, which was calcined at 900 ºC for 1h, compacted into a pellet form and sintered at 1200 ºC for 2h. The obtained ceramic body was characterized by SEM, XRD and FTIR. In vitro test for bioactivity verification was performed in SBF (Simulated Body Fluid) at pH 7.25 and 37 ºC. A surface deposition of hydroxyapatite on the ceramic body was observed after 3 days. The cytotoxicity test revealed that the material has cell viability above 70%, meaning that it is not toxic for the cells, according to ISO 10993-5 standard.
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