• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.761-764
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• 2009

Ag-Doped bioactive ceramic composites were prepared by colloidal silver solution. The physical properties of colloidal silver solution and Ag-Doped bioactive ceramic composites were characterized by Scanning electron microscopy(SEM), X-Ray Diffractometer(XRD) and Raman spectrophotometer respectively. According to XRD, we have identified that the chloride ion was chemically attached silver nano particles. SEM studies showed that silver chloride phases were homogeneously distributed on the Ag-Doped bioactive ceramic composites surface. Finally, we concluded that the silver chloride phase on the Ag-Doped bioactive ceramic composites surface was strongly prevent formation of Ag-hydroxyapatite.

• Journal of Technologic Dentistry
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• v.25 no.1
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• pp.21-28
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• 2003

The purpose of this study was to process bio-active glass ceramic composite, reinforced with sapphire fibers, by hot press. Also to study the interface of the matrix and the sapphire fiber, and the mechanical properties. Glass raw materials melted in Pt crucible at 1300$^{\circ}C$ during 3.5 hours. The melt was crushed in ball mill and then crushed material, ground and sieved to $<40{\beta}{\mu}m$. Sapphire fibers cut (30mm) and aligned. Powder and fibers hot pressed. The micrographs show good bonding between the matrix and the fiber and no porosity in the glass matrix. This means ideal fracture phenomena. Glass is fractured before the fiber. This is indication of good fracture strength. EDXS showing aluminum rich phase and crystalline phase. Bright field image of the matrix showing crystalline phase. Also diffraction pattern of TEM showing the crystalline phase and more than one phase. Strength of the samples was determined by 3 point bend testing. Strength of the 10vol% sample was approximately 69MPa, while strength of the control sample is 35MPa. Conclusions through this study as follow: 1. Micrographs show no porosity in the glass matrix and the interface. 2. The interface between the fiber and the glass matrix show no gaps. 3. Fracture of the glass indicates characteristic fiber-matrix separation. 4. Presence of crystalline phase at high processing temperature. 5. Sapphire is compatible with bioactive glass.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.205-210
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• 2019

Bioactive glass (BG) finds limited use as a bone replacement material owing to its low mechanical properties. In order to solve this problem, the micro-sized 13-93 BG was prepared as a fabric composite with SiC microfibers, and its mechanical properties and biocompatibility were investigated in this study. The tensile strengths of BG-SiC fiber-bundle composites increased in proportion to the number of SiC fibers. In particular, even when only one SiC fiber was substituted, the tensile strength increased by 81% to 1428 MPa. In the early stage of the in-vitro test, a silica-rich layer was formed on the surface of the 13-93 BG fibers. With time, calcium phosphate grew on the silica-rich layer and the BG fibers were delaminated. On the other hand, no products were observed on the SiC fibers for 7 days, therefore, SiC fibers are expected to maintain their strength even after transplantation in the body.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.18.2-18
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.224.1-224
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• 2003

• Journal of the Korean Ceramic Society
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• v.44 no.6 s.301
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• pp.291-296
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• 2007

Porous $Al_2O_3-(m-ZrO_2)$ composites were fabricated by pressureless sintering, using different volume percentages (40% - 60%) of poly methyl methacrylate (PMMA) powders as a pore-forming agent. The pore-forming agent was successfully removed, and the pore size and shape were well-controlled during the burn-out and sintering processes. The average pore size in the porous $Al_2O_3-(m-ZrO_2)$ bodies was about $200\;{\mu}m$ in diameter. The values of relative density, bending strength, hardness, and elastic modulus decreased as the PMMA content increased; i.e., in the porous body (sintered at $1500^{\circ}C$) using 55 vol % PMMA, their values were about 50.8%, 29.8 MPa, 266.4 Hv, and 6.4 GPa, respectively. To make the $Al_2O_3-(m-ZrO_2)$/polymer hybrid composites, a bioactive polymer, such as PMMA, was infiltrated into the porous $Al_2O_3-(m-ZrO_2)$ composites. After infiltration, most of the pores in the porous $Al_2O_3-(m-ZrO_2)$ composites, which were made using 60 vol % PMMA additions, were infiltrated with PMMA, and their values of relative density, bending strength, hardness, and elastic modulus remarkably increased.

• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.374-379
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• 2015

Mullite-matrix and $Al_2O_3$-matrix composites were fabricated with 30 wt% hydroxyapatite (HA) and tricalcium phosphate (TCP), respectively, as additives to give bioactivity. A diphasic gel process was employed to lower the densification temperature of the mullite matrix to $1320^{\circ}C$. A polymer complexation process was used to synthesize a TCP powder that was fully densified at $1250^{\circ}C$, for application to the matrix. For the HA/mullite composite, HA decomposed during sintering by reactions with the matrix components of $Al_2O_3$ and $SiO_2$, resulting in a mixture of $Al_2O_3$, TCP, and other minor phases with a low densification of less than 88% of the theoretical density (TD). In contrast, the TCP/$Al_2O_3$ composite was highly densified by sintering at $1350^{\circ}C$ to 96%TD with no reaction between the components. Different from the TCP monolith, the TCP/$Al_2O_3$ composite also showed a fine microstructure and intergranular fracture, both of which characteristics are advantageous for strength and fracture toughness.

• Journal of the Korean Ceramic Society
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• v.45 no.1
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• pp.1-29
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• 2008

In last two decades, an impressive progress has been recorded in terms of developing new materials or refining existing material composition/microstructure in order to obtain better performance in biomedical applications. The success of such efforts clearly demands better understanding of various concepts, e.g. biocompatibility, host response, cell-biomaterial interaction. In this article, we review the fundamental understanding that is required with respect to biomaterials development, as well as various materials and their properties, which are relevant in applications, such as hard tissue replacement. A major emphasize has been placed to present various design aspects, in terms of materials processing, of ceramics and polymer based biocomposites, Among the bioceramic composites, the research results obtained with Hydroxyapatite (HAp)-based biomaterials with metallic (Ti) or ceramic (Mullite) reinforcements as well as $SiO_2-MgO-Al_2O_3-K_2O-B_2O_3-F$ glass ceramics and stabilized $ZrO_2$ based bioinert ceramics are summarized. The physical as well as tribological properties of Polyethylene (PE) based hybrid biocomposites are discussed to illustrate the concept on how can the physical/wear properties be enhanced along with biocompatibility due to combined addition of bioinert and bioactive ceramic to a bioinert polymeric matrix. The tribological and corrosion properties of some important orthopedic metallic alloys based on Ti or Co-Cr-Mo are also illustrated. At the close, the future perspective on orthopedic biomaterials development and some unresolved issues are presented.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.319-330
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• 2005

Over the past few decades, much effort has been made to improve the mechanical and biological performance of HA, in order to extend its range of applications. As a major inorganic component of human hard tissues, hydroxyapatite bioceramic is regarded as being one of the most biocompatible materials. Numerous in vitro and in vivo studies have confirmed its excellent bioactivity, osteoconductivity and bone forming ability. However, because of its poor mechanical properties, its use in hard tissue applications has been restricted to those areas in which it can be used in the form of small sized powders/granules or in the non-load bearing sites. A number of researchers have focused on improving the mechanical and biological performance of HA, as well as on the formulation of hybrid and composite systems in order to extend its range of applications. In this article, we reviewed our recent works on HA-based biomaterials; i) the strengthening of HA with ceramic oxides, ii) HA-based bioactive coatings on metallic implants, iii) HA-based porous scaffolds and iv) HA-polymer hybrids/composites.