• 한국세라믹학회지
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• 제45권10호
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• pp.584-588
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• 2008

Porous hydroxyapatite(HA) and HA-coated porous $Al_2O_3$ possessing pore characteristics required for bone substitutes were prepared by a slurry foaming method combined with gelcasting. The HA coating was deposited by heating porous $Al_2O_3$ substrates in an aqueous solution containing $Ca^{2+}$ and ${PO_4}^{3-}$ ions at $65{\sim}95^{\circ}C$ under ambient pressure. The pore characteristic, microstructure, and compressive strength were investigated and compared for the two kinds of samples. The porosity of the samples was about 81% and 80% for HA and $Al_2O_3$, respectively with a highly interconnected network of spherical pores with size ranging from 50 to $250{\mu}m$. The porous $Al_2O_3$ sample showed much higher compressive strength(25 MPa) than the porous HA sample(10 MPa). Fairly dense and uniform HA coating(about $2{\mu}m$ thick) was deposited on the porous $Al_2O_3$ sample. Since the compressive strength of cancellous bone is $2{\sim}12$ MPa, both the porous HA and HA-coated porous $Al_2O_3$ samples could be successfully utilized as scaffolds for bone repair. Especially the latter is expected suitable for load bearing bone substitutes due to its excellent strength.

• 대한의용생체공학회:의공학회지
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• 제24권5호
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• pp.447-451
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• 2003

준분자 동력학 기법을 적용한 새로운 골-재형성 해석 방법을 제안 하였다. 본 연구에서는 기존의 연구에서 고려하지 못 하였던 해변골 내의 유체 압력이 골-재형성에 미치는 영향 까지를 고려한 해석 모델이 제안 되었다. 골-재형성의 대상 모델로 추체 시상면상의 2-D 모델을 개발 하였으며, 약 2kN의 수직 압축력에 해당되는 1.8564mm의 일정 변위 조건에 따른 모델내의 준분자들의 재배치 과정을 해석 하였다. 수렴된 피질골 및 해면골 모델의 준 분자의 형상은 실제 추체의 모양과 일치된 형태를 보이고 있었으며 계산된 수핵 압력 변화도 기존의 in-Vitro 실험 결과와 비교적 일치 하여 본 모델의 타당성을 입증 할 수 있었다.

• 구강회복응용과학지
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• 제30권3호
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• pp.215-222
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• 2014

본 연구는 수평적, 수직적 안면 골격 유형에 따른 하악 전치부 치조골의 형태학적 차이를 알아보기 위하여 시행 하였다. 연구 재료 및 방법: 40명의 Cone-beam computed tomography (Cone-beam CT)를 선별하여, 4개 군으로 분류하였다. Cone-beam CT 자료를 이용하여 하악 전치부 치조골의 부피($mm^3$), 하악 4절치 치축 기준 시상단면의 단면적(총 단면적, 해면골 단면적: $mm^2$), 백악법랑경계(cemento-enamel junction: CEJ) 2 mm, 3 mm 아래 순, 설측 치조골 두께를 측정하였다. 통계분석은 GLM, Kruskal-Wallis test and Tukey HSD를 사용하였다. 결과: 측절치의 백악법랑경계 2 mm, 3 mm 하방 설측 치조골 두께가, Class I low angle군이 나머지 3군 보다 두꺼웠다 (P < 0.05). 하악 전치 치조골의 부피, 전체 치조골 및 해면골의 단면에서의 통계적으로 유의한 차이는 없었다. 결론: Class I low angle군은 Class II high angle군에 비해 하악 전치 치조골의 설측 부위가 더 두껍다.

• 한국임상수의학회지
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• 제29권5호
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• pp.412-415
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• 2012

1년령의 중성화된 수컷 요크셔테리어와 7년령의 암컷 푸들이 골절의 지연유합으로 내원하였다. 요크셔테리어의 경우 오른쪽 요골과 척골의 원위부가 골절되었고, 푸들의 경우 왼쪽 경골과 비골의 원위부가 골절되었다. 두 환자에서 신체검사 및 방사선검사를 통해 골절의 유합이 지연되고 있음을 확인하였다. 골절부는 금속판 및 나사못으로 고정시키고 자가해면질골을 골절 틈새에 이식하였다. 또한 빠른 골유합을 위해 $20{\mu}g$의 rh-BMP 2 가 포함된 matrigel을 골절부에 주입하였다. 수술 후 방사선검사를 통해 골절부의 치유 상태를 확인하였다. 장기간의 방사선검사에서 두 마리 모두 빠른 골유합을 보였다. 첫 증례에서는 방사선사진상에서 2주째에 요골과 척골 골절 틈새에 골밀도가 증가하였다. 20주째에는 골절선이 더 이상 관찰되지 않았으며, 정상 외관을 회복하였다. 두 번째 증례에서는 방사선사진상에서 11주째에 골절 치유가 진행되고 있음이 확인되었다. 이 두 증례 모두 예상한 것보다 골절의 치유가 빠르게 일어났다. 따라서 rh-BMP 2와 matrigel은 지연유합된 골절의 치유를 촉진하는데 효과가 있다고 생각된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권2호
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• pp.100-104
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• 2023

Autogenous bone grafts from the mandibular ramus are a known source of inadequate bone volume scenarios of the residual alveolar ridge. However, the conventional block-type harvesting technique cannot prevent bone marrow invasion, which can cause postoperative complications such as pain, swelling, and inferior alveolar nerve injury. This study aims to suggest a complication-free harvesting technique and present the results of bone grafting and donor sites. One patient received two dental implants with a complication-free harvesting technique that involves creation of ditching holes with a 1 mm round bur. Sagittal, coronal, and axial osteotomies produced grid-type cortical squares using a micro-saw and a round bur to confirm the cortical thickness. The grid-type cortical bone was harvested from the occlusal aspect, and the harvesting was extended through an additional osteotomy on the exposed and remaining cortical bone to prevent bone marrow invasion. The patient did not suffer postoperative severe pain, swelling, or numbness. After 15 months, the harvested site exhibited new cortical bone lining, and the grafted area had healed to a cortico-cancellous complex with functional loading of the implants. Our technique, grid-type cortical bone harvesting without bone marrow invasion, allowed application of autogenous bone without bone marrow invasion to achieve acceptable bone healing of the dental implants and to regenerate the harvested cortical bone.

• 대한치과보철학회지
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• 제38권5호
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• pp.631-639
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• 2000

Root-form endosseous implants which are in use today have a variety of materials, designs and surface characteristics. Among them, pure titanium surface implants and titanium matrix coated with HA are popular as well as are available in many studies. Rate of clinical success is obviously lower in jaw with cancellous bone than dense bone. In order to increase the rate of success in poor bone quality. More advanced techniques of implant surgery and surface treatment of implant fixture body have been developed. As a successful result, the installation of HA coated implant in bone quality type III or IV became highly successful. Since most clinical studies were performed without knowing the characteristics of HA coated implants, it has been impossible to come up with proper clinical data. Therefore the characterization of HA coated implants is essential to understand long term clinical performance and the predictability of HA coated implant system Our results showed that HA coated implants had the success rate at 93.7% in bone quality type III, IV for 3.8 years, and the fixture of Steri-Oss showed more stability with time.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.491-510
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• 2005

This study was performed to evaluate the effect of inorganic polyphosphate on bone formation in the calvaria of rabbit in the procedure of guided bone regeneration with bovine cancellous bone graft and titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group I used only TR-ePTFE membrane, control group II used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in saline, experimental group III and IV used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 1% or 2% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 12 rabbits with titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in saline or inorganic polyphosphate. The animals were sacrificed at 2 weeks, 4 weeks, and 8 weeks after the surgery. Decalcified and non-decalcified specimens were processed for histologic and immunohistochemistric analysis. 1. Titanium reinforced ePTFE(TR-ePTFE) membrane showed good spacemaking and cell occlusiveness capability, but it showed poor wound stabilization. 2. The deproteinized bovine bone mineral did not promote bone regeneration, but it acted as a space filler. 3. There was no complete resorption of the deproteinized bovine bone mineral within 8 weeks. 4. 1% inorganic polyphosphate did not promote bone formation, but 2% inorganic polyphosphate promoted bone formation. Within the above results, 2% inorganic polyphosphate could be used effectively for bone regeneration.

• 대한한방부인과학회지
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• 제18권3호
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• pp.32-50
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• 2005

Purpose : This study was carried out to investigated the effects of Saenghyeolbosu-Tang on the morphometric changes of femur, and on the hormones and cytokines associated with bone metabolism in ovariectomized rats. Methods : Twenty-four female Sprague-Dawley rats were divided into sham operated group(normal), ovariectomized group(control), and treated with extract of Saenghyeolbosu-Tang group(treated). Each group was evaluated the changes of body weight at 0, 3, 6, 8, weeks after ovariectomy. Morphometric analysis(femur weight, femur/body weight, femur ash weight, femur ash/body weight, cross sectional area of compact bone and cancellous bone of femur) and histopathological examination were performed at 8 weeks after ovariectomy. Estrogen and cytokines($TNF-{\alpha},\;IL-1{\beta}$, IL-6) assay were performed at 8 weeks after ovariectomy. Results : 1. The femur weight(g) of treated group(1.59${\pm}$0.08) was significantly increased(p<0.05)compared with the control group(1.50${\pm}$0.07) at 8 weeks. 2. The femur/body weight(g) of treated group(5.27${\pm}$0.36) was significantly increased(p<0.05) compared with the control group(4.78${\pm}$0.37) at 8 weeks. 3. In the cross sectional area of cancellous bone of femur(${mm^2}$) the treated group(1.60${\pm}$0.20)was significantly increased(p<0.01) compared with the control group(1.19${\pm}$0.19) at 8 weeks. 4. The serum estrogen level(pg/ml) of treated(83.67${\pm}$27.44) and control group(800.49${\pm}$22.27)showed no significantly different changes at 8 weeks. 5. The serum $TNF-{\alpha}$ level(pg/ml) of treated(33.71${\pm}$6.43) and control group(41.35${\pm}$8.47) showed no significantly different changes at 8 weeks. 6. The serum $IL-1{\beta}$ level(pg/ml) of treated group(53.78${\pm}$10.83) was significantly decreased(p<0.001) compared with the control group(79.80${\pm}$11.40) at 8 weeks. 7. The serum IL-6 level(pg/ml) of treated group(55.52${\pm}$9.02) was significantly decreased(p<0.01) compared with the control group(69.69${\pm}$7.95) at 8 weeks. Conclusion : This study shows that Saenghyeolbosu-Tang inhibits bone resolution in ovariectomized rats. These results may be related to the inhibitory effect of Saenghyeolbosu-Tang on the secretion of $IL-1{\beta}$ and IL-6 in the Pathogenesis of　osteoporosis.

• 대한치과보철학회지
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• 제34권1호
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• pp.187-200
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• 1996

After loss of tooth, initial healing process is critical to preserve residual alveolar process. This study was conducted to compare the effect of hydroxylapatite particle synthetic graft and guided tissue regeneration procedure on healing of extraction wounds in 5 mongrel dogs. To investigate the maturity of bone and velocity of bone heating, bone-labeled tracers were used. After 16 weeks healing period, dogs were sacrificed. The specimens were treated with Villanueva bone stain. Fluorescence microscopy and polarized microscopy were performed to exam the pattern of bone formation in the extraction socket. The results were following ; 1. Pattern of bone regeneration in the group of hydroxylapatie graft and the group of membrane protection after hydroxylapatite graft was following ; bone regeneration was slow, regenerated bone was immature, and thickness of cortical layer was thin compare to that of untreated control group. 2. Cortical layers in membrane protected group were somewhat thicker but less condense to that of untreated control group. 3. Infiltration of inflammation cells were found in the groups using hydroxylapatite graft and membrane. We concluded that grafting of replamineform hydroxylapatite particles into the extraction socket delayed healing of the wound and disturbed the formation of cortical bone at the roof of extraction socket. The placement of expanded polytetrafluoroethylene membranes on the extraction socket promotes the bone regeneration. But newly formed bone in cortical layer consists of the cortico-cancellous bone in comparison with the cortical bone of the control group.