• Journal of Periodontal and Implant Science
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• v.15 no.1
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• pp.83.2-83.2
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• 1985

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.41-44
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• 2001

A composite of $Ca_3$(PO$_4$)$_2$ and MgAl$_2$O$_4$ spinel is biologically active and has enduring strength. Its strength depends on the spinel phase. The flaws in the spinel depend on the grain size of the calcium phosphate phase and are not altered by dissolution. The calcium phosphate, ${\alpha}$ tri-calcium phosphate, controls the tissue response. Bone bonds to the implant. A design for a bone graft as a replacement for a section of the diaphysis of a canine femur provides for tensile, compressive, torsional and bending load; and for the physiological processes of bonding and remodeling. A bone plate, used to stabilize the implant at time of surgery was removed after about one year. Over seven years of service have been achieved without internal or external fixation.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.27-46
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• 1996

The purpose of this study was designed to compare with the effects of 4 different surface active bioceramics on the healing process of alveolar bone defects in dogs. Artificial alveolar bone defects depth 4-6mm, width 3-4mm) were created with # 6 round bur at interproximal areas of maxillary canine, maxillary 2nd premolar, mandibular canine, and mandibular 3rd premolar. porous hydroxyapatite(Interpore $200^R$) , 45S5 bioglass, CJ4/lOC crystalline glass, and JJ crystalline glass were implanted in intrabony defects randomly. Experimental groups were divided into 4 categories according to its implant material. After implantation, all groups were examined postoperatively 4 weeks to 12 weeks. 3 dogs was selected randomly and sacrificed after vascular perfusion with 2.5% glutaraldehyde at every 4 weeks. Tissue blocks with surroundig alveolar bone and soft tissues were removed and immersed in formaldehyde/glutaraldehyde fixative. After 20 weeks decalcification with EDTA and formic acid, sections were made and observed under light microscope and transmission electron microscope. In all experimental groups, the encapsulation of inactive connective tissue was observed around graft particles in 4 weeks. As time elapsed, the thickness of surrounding connective tissue was decreased. Osteoconductive bone growth pattern was seen apparently in all groups. CJ4/lOC crystalline glass showed the most active bone formation until 8 weeks. 45S5 bioglass was, however, the most active in new bone formation at 12 weeks. Though there was difference in resorption rate among grafting materials, the size of graft particles was decreased gradually. 45S5 bioglass was resorbed faster than the others. On the other hand, porous hydroxyapatite was degraded most slowly. Phagocytosed particulate matters was observed in the cytoplasm of multinuclear multinuclear giant cell and macrophage under transmission electron microscope. The results suggested suggested that 45S5 bioglass and CJ4/lOC crystalline glass may have some enhanced reparative potential when compared to porous hydroxapatite in the treatment of periodontal defeds. JJ crystalline glass reguires a further investigation of the safety of its use.

• Journal of the Korean Ceramic Society
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• v.26 no.2
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• pp.171-178
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• 1989

In order to develope hydroxyapatite ceramics which has mechanical strength as bio-implant materials and get the basic data for the study and application of biocompatibility, hydroxyapatite was synthesized at Ca/P=1.67~1.75, pH 7~11 by precipitation method. Using prepared powders, the sintered body, fluorine substituted body and the porous body was formed and their properties were investigated. The sample obtained in condition of Ca/P=1.67, pH 7 and sintering at 1,15$0^{\circ}C$ was decomposed to $\beta$-tricalcium phosphate, and co-existed with hydroxyapatite. Hydroxyapatite synthesized at pH 11 was not easily decomposed to $\beta$-tricalcium phosphate at sintering process. The substitution of a small amount of fluorine for hydroxyapatite prevented hydroxyapatite from being decompsed to $\beta$-tricalcium phosphate. Hydroxyapatite ceramics which substited of 10% fluorine was prepared at 1,15$0^{\circ}C$, and the valueof bending strength for this body were found to be 112MPa.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.47-67
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• 1996

The purpose of this study was to observe the effect of $Biocoral^R$ graft and bioglass 45S5 graft in combination with ePTFE membrane in periodontal osseous defects for new bone formation. Nine healthy dogs were used. Under general anesthesia, 3-wall defects were created on the mesial and distal surfaces of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars. To induce periodontitis, a silicone rubber, $Provil^R$ light body, was injected under pressure into the defects. Ninety days later, $Provil^R$was removed and followed by thorough root planing. The followings were then applied in the mesial and distal defects of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars by random selections : 1) ePTFE membrane only application, 2) $Biocoral^R$ graft, 3) $Biocoral^R$ graft and ePTFE membrane application, 4)Bioglass 45S5 graft, 5) Bioglass 45S5 graft and ePTFE membrane application. The membranes were removed 1 month later. The dogs were sacrified at 1, 2 and 3 months following the graft, and block sections were made, demineralized, embedded, stained and examined by light microscope and transmission electron microscope. On the sections from teeth treated with ePTFE membrane only, the defect demonstrated extensive connnective tissue and alveolar bone regeneration. The $Biocoral^R$ graft group demonstrated extensive bone regeneration compared with ePTFE membrane only group. In the $Biocoral^R$ graft plus ePTFE membrane group, regeneration of new alveolus and crest occurred within the defect. As the experimental period lengthened, bone regeneration was increased and bone bridge was formed among the graft particles. The but bioglass 45S5 graft group demonstrated extensive bone regeneration but the amount of new bone was less than that of the $Biocoral^R$ graft group. For the bioglass 45S5 graft plus ePTFE membrane group, the amount of new bone was also increased. As the experimental period lengthened, bone regeneration was increased. Multinucleated giant cells, fibroblasts and macrophages were observed. As the bone formation was increased, the number of such cells was decreased. In conclusion, the $Biocoral^R$ was found better than the bioglass 45S5 for new bone formation, and the use of ePTFE membrane alone or with $Biocoral^R$/bioglass 45S5 can be supported as potential methods of promoting bone formation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.5
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• pp.191-198
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• 2022

Zirconia and titanium alloys, which are mainly used for dental implant materials, have poor osseointegration and osteogenesis abilities due to their bioinertness with low bioactivity on surface. In order to improve their surface bioinertness, surface modification with a bioactive material is an easy and simple method. In this study, akermanite (Ca₂MgSi₂O₇), a silicate-based bioceramic material with excellent bone bonding ability, was synthesized by a solid-state reaction and investigated its bioactivity from the analysis of surface dissolution and precipitation of hydroxyapatite particles in SBF solution. Calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), and silicon dioxide (SiO₂) were used as starting materials. After homogeneous mixing of starting materials by ball milling and the drying of at oven, uniaxial pressing was performed to form a compacted disk, and then heat-treated at high temperature to induce the solid-state reaction to akermanite. Bioactivity of synthesized akermanite disk was evaluated with the reaction temperature from the immersion test in SBF solution. The higher the reaction temperature, the more pronounced the akermanite phase and the less the surface dissolution at particle surface. It resulted that synthesized akermanite particles had high bioactivity on particle surface, but it depended on reacted temperature and phase composition. Moderate dissolution occurred at particle surfaces and observed the new precipitated hydroxyapatite particles in synthetic akermanite with solid-state reaction at 1100℃.