• 대한치과보철학회지
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• 제44권2호
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• pp.217-228
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• 2006

Statement of problem: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. Purpose: Primary objective was to investigate the influences or the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. Results: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. Conclusion: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.

• 한국정보전자통신기술학회논문지
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• 제5권4호
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• pp.216-223
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• 2012

임플란트 삽입 시 뼈의 회복기간은 약 8주에서 12주가 소요되는데, 이 때 임플란트 주위에서 발생하는 뼈의 회복작용 다시 말하여 골융합은 임플란트의 사용에 있어서 매우 중요한 역할을 한다. 이 조사논문에서는 골융합의 촉진작용으로 직접적인 기계적 자극, 초음파에 의한 자극, 레이져에 의한 자극, LED에 의한 자극을 비교 하였으며, 이번 조사를 통해서 자극 방법에 상관없이 $1.47^{\sim}1.6MHz$의 자극이 가장 이상적임을 찾아내었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권6호
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• pp.616-621
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• 2008

Osseointegration is a result of bone formation and bone regeneration processes, which takes place at the interface between bone and implant, and it indicates a rigid fixation that can be stably maintained while functional loading is applied inside the oral cavity as well as after implant placement. Although many researches were carried out about osseointegration mechanism, but cellular and molecular events have not been clarified. With recent development of molecular biology, some researches have examined biological determinants, such as cytokine, growth factors, bone matrix proteins, during osseointegration between bone and implant surface, other researches attempted to study the ways to increase bone formation by adhering protein to implant surface or by inserting growth factors during implant placement. Cellular research on the reaction of osteoblast especially to surface morphology (e.g. increased roughness) has been carried out and found that the surface roughness of titanium implant affects the growth of osteoblast, cytokine formation and mineralization. While molecular biological research in dental implant is burgeoning. Yet, its results are insignificant. We have been studying the roles of growth factors during osseointegration, comparing different manifestations of growth factors by studying the effect of osseointegration that varied by implant surface. Of many growth factors, $TGF-{\beta}$, IGF-I, BMP2, and BMP4, which plays a significant role in bone formation, were selected, and examined if these growth factors are manifested during osseointegration. The purpose of this article is to present result of our researches and encourage molecular researches in dental implant.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1373-1377
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• 2003

Current prostheses for amputees are generally extrinsic wearing socket type that the coupling between body stump and appliance wraps the soft tissue and this structure causes several problems :applying direct weight to soft tissue such as skin and muscle, skin trouble of contacting area and pain. In this study, osseointegration implant is a method to directly connect prosthesis to the residual stump skeletal tissue of arm, finger and leg through surgical operation. Technology presented in this paper essentially solves the problems of pain and abnormal weight transfer system indicated above and recovers the functions of the amputated arm and leg. In this paper, implant shape was designed for the first step for the development of osseointegration implant and then we studied the possibility to apply this osseointegration implant to human body by performing implant insertion operation to beagle tibia for the clinical animal test and normal beagle's gait analysis was executed in order to quantitatively verify the beagle's skeletal functions after the implant insertion.

• 대한치과의사협회지
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• 제46권8호
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• pp.494-504
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• 2008

Osseointegration is a result of bone formation and bone regeneration process, which take place at the interface between bone and implant and biologic determinants such as cytokine, growth factors, bone matrix proteins play an important role in osseointegration. The purpose of this study is to compare the expressoin of TGF-$\beta$, IGF-I, BMP2, BMP4 during osseointegration. We designed an experimental group which was inserted with a RBM surface titanium implants and machined surface, and compared with a control group which had a simple bone cavity and normal bone. Titanium implants were placed into tibia of 8 rabbits. We compared the expression of TGF-$\beta$, IGF-I, BMP2, BMP4 using RT_PCR (reverse transcriptase chain reaction)analysis in day 3,7,14 and 28 of implant insertion. According to the results, growth factors of experimental groups were more expressed than control groups. Among experimental groups, expression of TGF-$\beta$, IGF-I, BMP4 of BMP group had tedency to increase more at 14th, 28th days than Machined surface group. Therefore, our results suggest that TGF-$\beta$, IGF-I, BMP4 are expressed within the bone around the implant and more increased around rough surface implants while osseointegration occurs after dental implant insertion.

• 대한수의학회지
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• 제44권1호
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• pp.131-136
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• 2004

Osseointegration involves anchoring dental implants to stable bone rather than to soft-tissue. Clinical osseointegration is currently defined as the process whereby alloplastic material is asymptomatically and rigidly fixed and maintained in bone during functional loading. Full osseointegration is necessary for the success of long-term dental implants. Recent developments in computer assisted measurement of bone formation have improved maxillofacial examination and osseointegration. Computer assisted examination has also proved effective in dental implantology. This investigation was aimed to determine osseointegration in immediate and delayed implantation in the dog mandible using dental computed tomography (CT) and bone scintigraphy. Five adult (mean age of 2 years) mongrel dogs with a mean weight of 9.1 kg were used in this investigation. Titanium alloy implant systems with 4 mm in diameter and 10 mm in length were chosen for insertion. The second and third left mandibular premolars in each dog were extracted for the delayed implant insertion. Twelve weeks later, the second and third right mandibular premolars were extracted for the immediate implant insertion. Before the delayed and immediate implantation procedures and 0, 4, 8, and 12 weeks after the insertions, dental CT and scintigraphy were conducted. The CT and scintigraphic images indicate that reconstruction of bone surrounding of the immediate implant can be as successful as reconstruction of bone surrounding of the delayed implant.

• Journal of Periodontal and Implant Science
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• 제50권6호
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• pp.392-405
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• 2020

Purpose: Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and periimplant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration. Methods: Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. In vivo and in vitro experiments were used to assess osteogenesis. Results: The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration. Conclusions: Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.

• 대한치과교정학회지
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• 제28권3호
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• pp.453-459
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• 1998

저자들은 임프란트 매식 후 골유착을 위한 초기 치유기간 이전에 악정형력이 임프란트 주위 조직에 미치는 영향을 관찰하기 위하여 가토 12마리의 양측 대퇴골에 임프란트를 식립하고 2주, 4주 그리고 6주후에 각각 300g의 악정형력을 Ni-Ti close coil spring을 이용하여 매식된 임프란트에 4주동안 가하고 관찰한 후 다음과 같은 결론을 얻었다. 1. 모든 실험군의 임프란트는 4주간의 악정형력 적용후에도 안정된 견고성을 유지하였다. 2. 2주 실험군에서 대조군에 비해 임프란트와 골조직 사이의 섬유조직 증식이 많이 관찰 되었으나 특이할만한 염증소견은 관찰되지 않았다. 3. 4주 실험군, 대조군에서는 2주 실험군, 대조군과 각각 비교하였을 때 보다 많은 양의 골재생이 관찰 되었으며 실험군과 대조군 모두에서 임프란트와 골조직 사이의 섬유조직은 관찰하기 힘들었다. 4. 6주에서는 실험군과 대조군 사이에 뚜렷한 차이가 발견되지 않았다. 이상의 결과로 보아 임프란트 주위의 골조직 재생이 충분하지 않아도 골의 양과 질이 우수해 임프란트 식립시 견고한 초기고정을 얻을 수 있다면 골유착이 완성되는 초기 치유기간 이전에도 치과교정적 고정원으로 사용가능할 것으로 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.46-54
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• 2005

Purpose: This study was performed in order to compare the osseointegration of 4 different surfaced implants in the dog's tibia which has thick dense cortical bone and loose marrow space. Materials & methods: Four mongrel dogs and four different surface types of implants, smooth surfaced AVANA implants, RBM surfaced AVANA implants, HA-coated Steri-Oss implants and SLA Bicon implants, were used in this study. The animals were divided into 4 groups on the basis of implant surface characteristics: Control group, RBM group, HA group, and SLA group. Three implants of each group were installed into the metaphysis of tibia of adult dogs. The animals were sacrificed at 8 weeks after implantation. The undecalcified specimens were prepared for histological examination and histomorphometric analysis of implant-bone contact ratios. Results: Radiographically and histologically good osseointegration of implant was observed in the dense cortical bone, but poor osseointegration was observed in the marrow space. Histologically more bone apposition to implant surface was found in rough surfaced groups than the smooth surfaced, Control group. In histomorphometric findings of cortical bone the average bone-implant contact ratios of HA group (95.4%, p<0.01), RBM group (87.1%, p<0.05), and SLA group (86.0%, p<0.05) were significantly higher than that of Control group (75.9%). In marrow space the average bone-implant contact ratios of HA group (76.1%, p<0.01) and SLA group (45.4%, p<0.05) were significantly higher than that of Control group (29.6%). The ratio of RBM group was higher than that of Control group but there was no significantly difference between RBM group and Control group. Conclusion: These results suggest that the rough surfaced implants can obtain the better osseointegration than the smooth surfaced implant in the cortical and marrow space and that HA-coated implants can obtain the best osseointegration in the marrow space among them.

• 대한치과교정학회지
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• 제46권6호
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• pp.386-394
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• 2016

Objective: The objective of the study was to evaluate the practicality and the validity of different surface treatments of self-drilling orthodontic mini-implants (OMIs) by comparing bone cutting capacity and osseointegration. Methods: Self-drilling OMIs were surface-treated in three ways: Acid etched (Etched), resorbable blasting media (RBM), partially resorbabla balsting media (Hybrid). We compared the bone cutting capacity by measuring insertion depths into artificial bone (polyurethane foam). To compare osseointegration, OMIs were placed in the tibia of 25 rabbits and the removal torque value was measured at 1, 2, 4, and 8 weeks after placement. The specimens were analyzed by optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Results: The bone cutting capacity of the etched and hybrid group was lower than the machined (control) group, and was most inhibited in the RBM group (p < 0.05). At 4 weeks, the removal torque in the machined group was significantly decreased (p < 0.05), but was increased in the etched group (p < 0.05). In the hybrid group, the removal torque significantly increased at 2 weeks, and was the highest among all measured values at 8 weeks (p < 0.05). The infiltration of bone-like tissue surface was evaluated by SEM, and calcium and phosphorus were detected via EDS only in the hybrid group. Conclusions: Partial RBM surface treatment (hybrid type in this study) produced the most stable self-drilling OMIs, without a corresponding reduction in bone cutting capacity.