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        검색결과 46

        21.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Demineralized Freeze Dried Bone(DFDB) graft material have been used for reconstruction of large bony defects or augmentation of thin alveolar ridge during implantation of titanium fixtures. But at present osteogenic effect of DFDB do not overcome the capacity of autogenic bone graft. Thus many investigators had applicated various bioactive substance to DFDB to enhance the ability of osteogenesis of DFDB. In this study, mixture of grafting material was made from fibrin glue(F) and DFDB(D)(group 1: F+D), fibrin glue, DFDB and rhBMP-2(B) (group 2: F+D+B), fibrin glue, DFDB, polylactic- co-glycolic acid(PLGA)(P) and rhBMP-2(goup 3: F+D+B+P), fibrin glue, DFDB, PLGA, rhBMP-2 and autogenic osteoblasts( O)(group 4: F+D+B+P+O), and fibrin glue, DFDB, autogenic osteoblasts (group 5: F+D+O). During first surgical procedure, extraction of molar teeth was performed at male Biggle dog's mandible, and collected bone marrow tissue from tibia at same Biggle dog. Collected bone marrow tissue was cultured and differentiated into osteoblasts in vitro, and stored in nitrogen bottle. After four months, titanium fixture was implanted with prepared graft material to Biggle dog's mandible. After four and eight weeks respectively, experimental dog was sacrificed. Obtained tissues were prepared for examination by using resin embedded ground section method. Prepared sections were evaluated with transmitted and polarized microscope, and areas of osteoid and cacified bone were calculated with IPTK 5.0( image processing tool kit version 5.0). Resultant data was statistically analyzed by SPSS 13.0 software. Results of this study showed that autogenic osteoblats had more enhancing capacity of bone formation than rhBMP-2, but PLGA inhibited bone forming potential of bony tissue.
        4,300원
        22.
        2008.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Porous Ti implant samples were fabricated by the sintering of spherical Ti powders in a high vacuum furnace. To increase their surface area and biocompatibility, anodic oxidation and a hydrothermal treatment were then applied. Electrolytes in a mixture of glycerophosphate and calcium acetate were used for the anodizing treatment. The resulting oxide layer was found to have precipitated in the phase form of anatase TiO2 and nano-scaled hydroxyapatite on the porous Ti implant surface. The porous Ti implant can be modified via an anodic oxidation method and a hydrothermal treatment for the enhancement of the bioactivity, and current multi-surface treatments can be applied for use in a dental implant system.
        4,000원
        23.
        2007.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Al-42wt%Nb powder was prepared by high-energy mechanical milling(HEMM). The particle size, phase transformation and microstructure of the as-milled powder were investigated by particle size distribution (PSD) analyzer, scanning electron microscopy (SEM), X-ray diffractometery (XRD), transmission electron microscopy (TEM)and differential thermal analysis (DTA). The milled powders were heated to a sintering temperature at 1000C with under vaccum with vaccum tube furnace. Microstructural examination of sintered Ti-42wt%Nb alloy using 4h-milled powder showed Ti-rich phases (α-Ti) which are fine and homogeneously distributed in the matrix (Nb-rich phase: β-Ti). The sintered Ti-42wt%Nb alloy with milled powder showed higher hardness. The microstructure of the as quenched specimens fabricated by sintering using mixed and milled powder almost are same, but the hardness of as quenched specimen fabricated by using mixed powder increased due to solution hardening of Nb in Ti matrix. The aging effect of these specimens on microstructural change and hardening is not prominent.
        4,000원
        24.
        2007.10 KCI 등재 구독 인증기관·개인회원 무료
        Nowdays, implant treatment became a branch of universal dental treatment and results in mOI‘ e success by surface con dit ioning and continuous improvements. Recently, a method to extract crystal shows sirnilar Ca/P ratio as HA has introduced which is anodizing electrolyte pure titanium anodize by electrolyte ß -glycerophosphate disodium salt hydrate and calcium acetic acid on pure t itanium before hydrothermal treatment ln t his study fixu res have divided in 3 group: Machined(Group 1), Anodized(Group 1I), implant whi ch has a surface containing Ca and P formed by anodization and hyd rothermal treatment( Group m). Total 18 fixtures were impla nted on rabbit which sacrifi ced on week 2 and week 4 for the histological specimens. By t hese specimens polarized microscopic view‘ ll1icro CT view‘ EPMA, ISQ value were ll1easured, cOll1pa red and a nalysed by each group to f igure out the possible clinical use of titanium implant containing Ca and P by hydrothe rll1al treatment and anodizing electrolyte. ISQ value had no s ignifïcance differences between each 3 groups, However in each group 4 , 8 weeks had hi gher ISQ value than 2 weeks 1n polarized rni croscope, calcification level was following Group 1I ‘ Group m, Group 1. 1n rnicro CT‘ formation of cancellous bone level was following ‘ Group 1I , Group m, Group 1. 1n EPMA, distribution and concentration of Ca was following : Group 1I was two t ill1es more higher than Group 1 , Group m. Group m were higher level t han Group 1. In distribution and concentration of P Group 1I was high er than the other group. but th e re were no statical s ignifi cances. Finally, anodi zed implant was the most exellent on the early bone for ll1a tion Containing Ca and P implant by anodizing and hydrotherma l treatment was more better than machined surface implant, but there is no effi cience at ear ly bone formati on
        25.
        2006.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research was designed to investigate changes of growth factors and bone matrix proteins during the bone healing processes using immunohistochemistry and in situ hybridization. Especially this study was focused on the changes of bone matrix and growth factors around the titanium implant. Threaded implants were introduced into the long bone of tibia. Time dependent changes of several bone associated protein and and its mRNAs were observed. Proteins investigated in this study are collagen, osteonectin(ON), osteopontin(OPN), osteocalcin(OC). Expression of the proteins were measured using immunohistochemistry. VEGF and ON were measured using in situ hybridization, and northen blot technique. Bone regeneration were observed as early as the third day of experiment. Matrix proteins and growth factors observed around implant were identical to the proteins observed in the control group. The expression of the ON, OC and VEGF were observed mainly in the osteoblast-like cell on the surface of new bone around the implant and the cells lining the margin of bone defect apart from the implant. The observation may not result from direct osteoconducting activities of titanium but by passive adsorption of extracellular factors which has bone inducing capacities. These passive adsorption results in the immobilization of the growth factors and consequent prolongation of the activities.
        4,000원
        29.
        2003.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        무발정 증상을 보이는 젖소 65두를 대상으로 몇 가지 호르몬 처리기법을 사용하여 소의 번식효율 향상시키고자 본 실험을 수행하였다. Group 1. Ovsynch program (GnRH-PGF a /PGF a/GnRH), Group 2. Two plus Two program (GnRH-PGF a /PGF a/GnRH), Group 3. progesterone implant (CIDR)-GnRH/PGF a/PGF a/GnRH과 Group 4. (Folli
        4,000원
        34.
        1998.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        임프란트의 외표면적이 골과의 결합의 정도에 미치는 영향을 알아보기 위하여 10개의 grade ll 티타늄 임프란트를 사용하여 이를 직경 3미리와 5미리의 2개의 군으로 나누어 10마리의 토끼의 무릅뼈에 삽입하였다. 6주후에 동물들을 희생시키고 회전제거력을 Tohnichi 15-BTG-N Torque garge Manometer로 측정하여 5nmwlrrud 그룹의 회전제거력이 3mm직경 그룹의 회전제거력보다 큰 것을 확인하였다. (p=0.008)
        3,000원
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