• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.1-28
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• 1990

The severe atrophic edentulism with poor neuromuscular control militates against successful conventional denture therapy. To such situation, a prescribing of dental implant treatment has been considered with some probability. Implant materials used as a trial for dental implants includes metals, plastic polymers and ceramics. The purpose of this study was to observe histologic response in osseointegration process at titanium implant-tissue interface based on biocompatibility at specific period of sequential natures which were divided into a half month, one, month, two months, three months and immediate as a base line. In this study, unilateral lower left premolar and molar teeth were extraced in three dogs. After allowing to heal for 6 months, three kinds of osseointegrated implant, $Br{\aa}nemark$, Corevent and kimplant(a prototype of SNU implant study)were inserted in each dog respectively according to the above sequence from front to back. The specimens were taken from those dogs at the same time since implant were inserted quite reverse order of the specified periods, and decalcified and processed for histologic examination for the light microscopy and the electron microscopy. The microscopic histologic findings at the interface between titanium implants and tissue were interpretated as follows : A. Light microscopic findings : a. Immediate : Implant were surrounded by compact bone and spongy bone. Microcrak was observed in the superficial bone tissue. Osteocytes were disappeared and bone lacunae were observed as a vacant space in some parts. In the contacting with the spongy bone, bone trabeculae and bone marrow were in contact with the implant. b. A half Month : Osteoblasts exist as a monolayer in th inner bone trabeculae and do bone additiocn. Osteoblasts&inflammatory cells were observed in some parts. c. One Month : The presence of osteoclasts decreased. Osteoblasts did active bone fromation, and bone marrow was in contact with the implant in the many places. d. Two Months : Bone formation was advanced in comparison with the b and c. The presence of osteoclsts was not observed. e. Three Months : The superficial bone tissue contacted with the implants was entirely composed by the compact bone. B. Electron microscopic findings : a. A half month and one month group : In the parts of the active bone formation, osteoblasts with the well developed endoplasmic reticulum and Golgi apparatus were arranged in the monolayer. In the parts of the bone resorption, ruffled border was well developed and many osteoclasts with the well-developed golgi apparatus, mitochondria, vacuole, vesicle and lysosome were existed. b. Three months group : No osteoblasts were observed in the superficial bone tissue. Bone matrix with collaen fiber was observed. c. No significant dirrerence in the histologic findings was observed in $Br{\aa}nemark$, Core-vent and kimplant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.425-429
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• 2011

Bone grafts are becoming increasingly common in oral and maxillofacial surgery to improve bone healing procedures. Bovine bone as a xenograft is a representative osteoconductor and space filler; however, sometimes complications, such as infection and wound dehiscence are encountered with its use. We report the result of an eight-year follow-up of a xenograft case and processing methods of inorganic bovine bone along with a review of the literature. Xenograft ($LUBBOC^{(R)}$) was used in a cyst enucleation site of the maxilla, as a bone substitute and space filler. Inflammation and infection were defined several times as lack of osseous contact between the graft and host bone, caused by remodeling failure over an eight-year period. Pathologic findings of the xenograft revealed dead bony trabeculae with inflamed fibrous tissue and actinomycosis.

• The korean journal of orthodontics
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• v.43 no.3
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• pp.120-126
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• 2013

Objective: To gain basic information regarding the biologic stability of plasma ion-implanted miniscrews and their potential clinical applications. Methods: Sixteen plasma ion-implanted and 16 sandblasted and acid-etched (SLA) miniscrews were bilaterally inserted in the mandibles of 4 beagles (2 miniscrews of each type per quadrant). Then, 250 - 300 gm of force from Ni-Ti coil springs was applied for 2 different periods: 12 weeks on one side and 3 weeks contralaterally. Thereafter, the animals were sacrificed and mandibular specimens including the miniscrews were collected. The insertion torque and mobility were compared between the groups. The bone-implant contact and bone volume ratio were calculated within 800 mm of the miniscrews and compared between the loading periods. The number of osteoblasts was also quantified. The measurements were expressed as percentages and analyzed by independent t-tests (p < 0.05). Results: No significant differences in any of the analyzed parameters were noted between the groups. Conclusions: The preliminary findings indicate that plasma ion-implanted miniscrews have similar biologic characteristics to SLA miniscrews in terms of insertion torque, mobility, bone-implant contact rate, and bone volume rate.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.307-314
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• 2005

After dental implant are planted into their bony site among the various growth factors associated with bone formation. BMP is expressed in the bone surrounding the implant fixture. By taking a close look at BMP2, BMP4 which are growth factors that take put in bone formation, its histologic features and radiographic bone healing patterns we would like to examine the mechanism of osseointegration. We randomly used 8 male and female house rabbit amd used diameter 5 mm height spiral shaped implants(Ostem, Korea) for animal use handled as a resorbable blast machined(RBM) surface and machined surface. 2group were formed and each group had RBM surface and machined surface implant or a simple bone cavity. After 3, 7, 14 and 28 days post surgery 2 objects were sacrificed from each group and histologic specimens were acquired. RT-PCR analysis was conducted and after H&E staining the extent of osseointegration was measured applying a histologic feature and histomorphometric analysis program. Quanitity one -4.41(Bio-Rad, USA) was used after scanning the PCR product image of the growth factors manifested in each group. According to the histomorphometric features the RBM, Machined surface group showed increased contact between bone and implant surface at 3, 7, 14 and 28 days after surgery. The BMP2 level increased in both experiment groups but remained unchanged in the contrast group. BMP4 levels stayed steady after the early post implantation period for RBM but showed decreased in the machined surface group and contrast group. The amount of contact between bone and implant surface increased with the passage of time. BMP2, BMP4 were expressed in both experimental group and contrast group. These growth factors play a role in osseointegration of implant.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.6
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• pp.671-678
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• 2004

Statement of problem. Reducing treatment time in implant dentistry is a matter of main concern. There are so many factors affecting the success rate of immediate or early loaded implant for the initial bone response. The especially microscopic properties of implant surfaces playa major role in the osseous healing of dental implant. Purpose. The aims of this study were to perform a histologic and histomorphometric comparison of the healing characteristics anodically roughened surface, HA coated surface and RBM surface implant, and to compare of ISQ values measured by $Osstell^{TM}$ for resonance frequency analysis in dogs mandible during 2 weeks. Material and method. Bone blocks from 2 dogs were caught after covered healing for 0 day(2 h); Group I, 1 week; Group II and 2 weeks; Group III. One longitudinal section was obtained for each implant and stained with hematoxylin and eosin. Histomorphometric analysis was done with Kappa Imagebase system to calculate bone-to-implant contact and bone volumes inside the threads. ISQ values were measured in every time of surgery schedule. Conclusion. The experiment revealed that: 1. The percentages of bone-to-implant contact on the fixture in each group were not significantly different(P > 0.05). 2. The percentages of bone area inside the threads on the fixture in each group were not significantly different(P > 0.05). 3. The ISQ level showed clinical stability of each fixture during 2 weeks(all ISQ level ${\geq}71$ ).

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.789-798
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• 2005

Primary stability is a fundamental criteria of implant success. There has been various trials to increase initial stability and bone to implant contact. The objective of osteotome technique is to preserve all the existing bone by minimizing or even eliminating the drilling sequence of the surgical protocol. The bone layer adjacent to the osteotomy site is progressively compacted with various bone condensers(osteotomes) this will result in a denser bone to implant contact. This improved bone density helps to optimize primary implant stability in low density bone. The use of wide implant is one of methods to increse primary stability. They can be used in special situations in which they can increase the surface area available for implant anchorage and improve their primary stability The aim of this study was to evaluate the influence of the osteotome technique and implant width on primary stability. Osteotome technique was compared with conventional drilling method by resonance frequency measurments according to the implant fixtures diameter. The results were as follows: 1. The average of ISQ value was sightly higher in osteotome technique, but there was not statistically significant in regular and narrow implant(p <0.05). 2. Either osteotome technique or conventional technique. ISQ value was significantly higer as increasing of implant diameter(p <0.05). 3. ISQ value of drilling technique was higer than those of osteotome technique in wide implant. It was assumed to be caused by difference in final preparation diameter.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.33-48
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• 2000

Purpose : To investigate osseointergration of titanium implants into the tibia of rabbits, which were fed a low calcium diet and irradiated. Materials and Methods : To prepare the experimental model, control group was fed a normal diet and experimental group was fed a low calcium diet for 4 weeks. And then, titanium implants were inserted into the tibia of each rabbit. Experimental group was subdivided into two groups; low calcium diet/non-irradiation group and low calcium diet/irradiation group. The low calcium diet/irradiation group was irradiated with a single absorbed dose of 15 Gy at the 5th postoperative day. At 12, 19, 33, 47, and 61 days after implantation (1, 2, 4, 6, and 8 weeks after irradiation), the bone formation in the bone-implant interface area was examined by light microscopy and fluorescent microscopy. Results and Conclusions: 1. In the control group, there began to form woven bone in the bone-implant interface area at 12 days after implantation. As the experimental time was going on, the amount of bone which was in contact with the implant was increased. 2. In the low calcium diet/non-irradiation group, there began to form woven bone in the bone-implant interface area at 19 days after implantation. Although the amount of bone which was in contact with the implant was increased as the experimental time was going on, the extent of increased bone was weak as compared with control group. 3. In the low calcium diet/irradiation group, there began to form woven bone incompletely in the bone-implant interface area at 19 days after implantation, but there were vascular connective tissues in the bone-implant interface area over the entire experimental period. 4. In the control group and low calcium diet/non-irradiation group, bone labeling bands were observed at 33 days after implantation, which suggests that the bone formation and remodeling was in process, but interstitial bone remodeling was not observed in the low calcium diet/irradiation group.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.179-180
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• 2006

In this study, the effect of stem-end design on contact pressure and stress distribution in revision TKR was investigated using finite element method. The finite element model of tibia, including the cortical bone, the cancellous bone and canal, was developed based on CT images. The stem models with various stem lengths, diameters and frictional coefficients, and press-fit effects were considered. The results showed that the longer stem length, the stronger press-fit, the bigger stem diameter, and the higher frictional coefficient increased both peak contact pressure and the highest Von-Mises stress values. We hypothesized that peak contact pressure and Von-Mises stress distribution around the stem, may be related to the stem end pain. The results of this study will be useful to design the stem endand reduce the end-of-stem pain in revision TKR.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.41-56
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• 2008

The methods of surface modification of commercial implants were various according to the manufacturer. Surface modification of implant may produce diverse physical and chemical surface characteristics resulted from the treatment method and treatment condition. As a result, the bone response might be different. Even though surface modified implants have been used clinically, most researches are focusing on the bone response of surface modified implants comparing to machined implants rather than surface modified commercial implants. This study compare and analyze bone responses of 4 surface modified commercial implants with different shapes and surfaces. Eighty surface modified commercial implants with 4 different surface characteristics were installed in the tibia of white Newzealand rabbits. Biomechanical stability tests and histomorphometric evaluation were done. The results were as follows: 1. Surface modified commercial implants showed stable osseointegration at 6 weeks after installation. 2. Histomorphometric evaluation showed that there was no significant differences in bone to implant contact among 4 different commercial titanium implants. In comparing the implants with different shape the measurement of bone growth in subcortical area would be more reliable than entire bone to implant contact length. 3. Resonance Frequency Analysis showed that there was no significant differences among 4 types of implants, even though they were significantly different in installation. 4. There was significant differences in interfacial shear strength among 4 type of implants. 5. It is difficult to observe accurate bone to implant interface using Micro-CT. However, it is possible to measure the entire contact length of the implant to the bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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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.