• Journal of Periodontal and Implant Science
• /
• 제38권2호
• /
• pp.125-134
• /
• 2008

Purpose: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study evaluated the bone regenerative effect of rhBMP-2 delivered with different carrier systems. Materials and Methods: 8 mm critical-sized rat calvarial defects were used in 60 male Sprague-Dawley rats. The animals were divided into 6 groups containing 10 animals each. Two groups were controls that had no treatment and absorbable collagen membrane only. 4 groups were experimentals that contained rhBMP-2 only and applied with absorbable collagen sponge($Collatape^{(R)}$), $MBCP^{(R)}$, Bio-$Oss^{(R)}$ each. The histological and histometric parameters were used to evaluate the defects after 2- or 8-week healing period. The shape and total augmented area were stable in all groups over the healing time. Results: New bone formation was significantly greater in the rhBMP-2 with carrier group than control group. rhBMP-2/ACS was the highest in bone density but gained less new bone area than rhBMP-2/$MBCP^{(R)}$ and rhBMP-2/Bio-$Oss^{(R)}$. The bone density after 8 weeks was greater than that after 2 weeks in all groups. However, rhBMP-2 alone failed to show the statistically significant difference in new bone area and bone density compared to control group. Also $MBCP^{(R)}$ and Bio-$Oss^{(R)}$ particles remained after 8 weeks healing period. Conclusion: These results suggest that rhBMP-2 with carrier system is an excellent inductive agent for bone formation and we can use it as the predictable bone tissue engieering technique. Future study will likely focus on the kinetics of BMP release and development of carriers that is ideal for it.

• 한국기록관리학회지
• /
• 제16권1호
• /
• pp.121-150
• /
• 2016

본 연구는 노근리디지털아카이브 구축을 위한 예비분석으로, 참여형 아카이브 구축을 위한 오픈소스 소프트웨어(Open Source Software)를 분석하였다. 노근리사건은 한국전쟁 중의 양민 학살 사건으로 1999년 처음 사건이 알려진 이래로 한미 양국의 서로 다른 정치적 환경에서 벌어진 진상 규명 과정과 연구 활동, 이후 사회문화적인 다양한 치유 과정을 거쳐왔다. 이에 사건의 본질적인 이해를 위해서는 사건의 전후 내용뿐만 아니라 양국의 사회적 이해와 사회 구성원의 기억이 중요한 의미를 가진다. 따라서 노근리디지털아카이브는 사회적 기억의 수집을 위하여 참여형이라는 방식을 도입해 디지털아카이브를 구축하고자 한다. 이를 위해 본 연구는 현 시점에서 디지털아카이브 구축의 도구로 활용 가능한 대표적인 OSS들을 선별하여 평가 분석하였다. 평가를 위해 기존 OSS 평가 연구들을 통하여 평가 기준들을 종합하고, 또 사회적 기억을 저장하기 위한 핵심 기능과 조건들을 고려하여 참여형디지털아카이브를 위한 평가 기준을 마련하였다. 이를 바탕으로 기존 디지털 프로젝트에 널리 사용 중인 OSS 중 6개 시스템을 선정하여 분석하였다. 각 OSS의 특성과 장단점을 통해, 사회적 기억이라는 콘텐츠를 담는 디지털아카이브에 적합한 OSS에 대해 논의하고자 하였다.

• 한국정보보호학회:학술대회논문집
• /
• 한국정보보호학회 1996년도 종합학술발표회논문집
• /
• pp.99-108
• /
• 1996

디지틀 서명을 구현하기 위해서는 몇 가지 중요한 요소 알고리즘들이 필요하게 된다. 본 논문에서는 이러한 구성 요소 알고리즘들에 대해 고찰해보며, 이러한 알고리즘들을 여러 가지 운영체제상에서 구현하여, 각 운영체제의 특성에 따른 구현결과를 비교해본다. 이러한 구현결과는 디지틀 서명 및 여러 가지 암호화 기술을 실제로 구현하는 경우 최적화가 가능한 운영체제 및 컴파일러 선택에 좋은 기준을 제공해 줄 수 있을 것이다.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
• /
• pp.745-745
• /
• 2006

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제14권1호
• /
• pp.31-39
• /
• 2008

센서노드 운영체제는 다종다양한 센서를 효율적으로 관리하기 위해서 통일된 API와 효율적인 디바이스 드라이버 매니저를 지원하여야 한다. 하지만 Tiny-OS, Nano-Q+ 등의 기존 운영체제들은 이와 같은 디바이스 드라이버 매니저를 지원하지 않는다. 본 논문에서는 센서 I/O 서브시스템을 제안하여 응용프로그래머에게 통일된 API를 제공하며 디바이스 드라이버의 장탈착이 용이한 디바이스 관리 매니저를 제시한다. 탈부착이 가능한 스마트 센서를 위하여 원격 디바이스 드라이버 업데이트 방식을 제안한다. 이 방식은 일부 센서가 변경되었을 때 전체 응용이 아닌 디바이스 드라이버만의 다운로딩이 가능하다. ETRI가 개발한 Nano-Q+에 상기한 기능을 추가하여 설계하고 구현하였다. 기존 운영체제와 성능을 비교 평가하였고 디바이스 드라이버 부분 다운로딩이 다운로딩 속도를 획기적으로 개선시켰다.

• Journal of Periodontal and Implant Science
• /
• 제39권3호
• /
• pp.321-329
• /
• 2009

Purpose: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. Methods: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight $3.0{\sim}3.5kg$). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The specimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. Results: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). Conclusions: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human application.

• Journal of Periodontal and Implant Science
• /
• 제33권3호
• /
• pp.533-542
• /
• 2003

The purpose of this study is to evaluate histologic result of bone substituting material on defects followed tooth extraction. We compare the histologic findings control, DFDBA, Bio-Oss(R), and $Regenafil^{TM}$, Briefly, mandibular premolar teeth were extracted available for bone filling. All alveolar sites were checked after extraction and thoroughly debrided with a dental curet to remove the periodontal ligament. Extraction sites were prepared dehiscence on buccal side 7mm height from alveolar crest. The graft materials were filled into the extraction socket and dehiscenc defects. The animals were sacrificed 12 weeks after implantation. Both treated and control mandibular sites were histologically evaluated with light microscopy. Histologic observation at 12 weeks revealed that control and experimental sites were healed uneventfully and directly apposed to new bone without any adverse tissue reaction. DFDBA and Bio-Ossn(R)sites maintain width of alveolar crest but were not fully resorbed. $Regenafil^{TM}$ sites also maintain width and particles were resorbed more than other graft materials. From this results, it was suggested that $Regenafil^{TM}$ is promising boen substituting materials maintaining the width of alveolar crest and height follewed tooth extraction.

• Imaging Science in Dentistry
• /
• 제47권1호
• /
• pp.51-55
• /
• 2017

Purpose: This study was conducted to suggest the development of a learning management system for dental radiology education using the Modular Object-Oriented Dynamic Learning Environment(Moodle). Materials and Methods: Moodle is a well-known and verified open-source software-learning management system (OSS-LMS). The Moodle software was installed on a server computer and customized for dental radiology education. The system was implemented for teaching undergraduate students to diagnose dental caries in panoramic images. Questions were chosen that could assess students' diagnosis ability. Students were given several questions corresponding to each of 100 panoramic images. Results: The installation and customization of Moodle was feasible, cost-effective, and time-saving. By having students answer questions repeatedly, it was possible to train them to examine panoramic images sequentially and thoroughly. Conclusion: Based on its educational efficiency and efficacy, the adaptation of an OSS-LMS in dental school may be highly recommended. The system could be extended to continuing education for dentists. Further studies on the objective evaluation of knowledge acquisition and retention are needed.

• 대한치과보철학회지
• /
• 제40권3호
• /
• pp.275-286
• /
• 2002

Statement of problem. Surface alteration of the implant screws after function may be associated with mechanical failure. Theses metal fatigue appears to be the most common cause of structural failure. Purpose. The purpose of this study was to evaluate surface alteration of the implant screws after function through the examination of used and unused implant screws in SEM(scanning electron microscope). Materials and methods. In this study, abutment screws(Steri-oss, 3i), gold retaining screw(3i) and titanium retaining screw(3i) were retrieved from patients. New, unused abutment and retaining screws were prepared for control group. Each of the old, used screws was retrieved with a screwdriver. And retrieved implant complex of Steri-oss system was prepared for this study. Then, SEM investigation and EDS analysis of abutment and retaining screws were performed. And SEM investigation of cross-sectioned sample of retrieved implant complex was performed. Results. In the case of new, unused implant screws, as maunfactured circumferential grooves are regularly examined and screw thread are sharply remained. Before ultrasonic cleansing of old, used implant screw, a lot of accumulation and corrosion products were existed. After ultrasonic cleansing of old, used implant screws, circumferential grooves as examined before function were randomly deepened and scratches increased. Also, dull screw thread was examined. More surface alterations after function were examined in titanium screw than gold screw. And more surface alteration was examined when retrieved with driver than retrieved without driver. Conclusions. These surface alteration after function may result in the screw instability. Regularly cleansing and exchange of screws was recommended. We recommend the use of gold screw rather than titanium screw, and careful manipulation of the driver.

• Journal of Periodontal and Implant Science
• /
• 제30권3호
• /
• pp.527-538
• /
• 2000

Several extraction cases with advanced bone loss as a result of periodontal disease, root or labial bone fracture, extensive caries, and periapical lesions occur esthetic, functional problems and severe bone loss. Therefore, to treat these cases used several surgical methods and socket preservation among this therapies have been evaluated simple, effective and good prognosis in the implant placement. Socket preservation therapy have been used with barrier membranes or/and graft materials. Deproteinized bovine bone mineral have been evaluated ideal grafting materials. Recently, calcium-phosphate thin film coated bovine bone powders were developed in our country, but the study for these material wasn't reported. When two types of xenograft materials were implanted in extraction sockets of Beagle dogs, the effects of these were analyzed after 4 weeks and 8 weeks histological views. The results of this study were as follows. 1. In control groups, 4 weeks after implantation, the extraction sockets were filled with connective tissue which has dilated vessels and epithelial growth. And after 8 weeks, irregular connective bundles were observed. But new bone formation was not seen. 2. In Bio-Oss groups, epithelial growth was not seen and bone powder was covered with connective tissue fiber. New bone formation was found around the interproximal bone. There was no special change seen after 8 weeks, connective tissue fibers became more regular, and bone growth near bone powder was not made well. 3. In Ca-P BBP groups, epithelial cells didn't grow in the extraction sockets, there was a lot of new bone made around the bone powder after 8 weeks, new bone around bone powder was replaced with mature bone. It is thought that bone powder grafting into the extraction sockets is very useful for conservation of ridge, and Ca-P BBP is more effective in bone formation than Bio-Oss.