• Journal of Periodontal and Implant Science
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• v.54 no.3
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• pp.177-188
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• 2024

Purpose: Placing dental implants in areas with low bone density or in conditions where bone healing is suppressed is challenging for clinicians. An experiment using a rodent model was performed with the aim of determining the efficacy of host modulation by increasing the systemic level of cholesterol sulfate (CS) using Irosustat in the context of the bone healing process around dental implants. Methods: In 16 ovariectomised female Sprague-Dawley rats, 2 implant fixtures were placed in the tibial bones (1 fixture on each side). At 1 week after surgery, the high-CS group (n=8) received Irosustat-mixed feed, while the control group (n=8) was fed conventionally. Block specimens were obtained at 5 weeks post-surgery for histologic analysis and the data were evaluated statistically (P<0.05). Results: Unlike the high-CS group, half of the specimens in the control group demonstrated severe bone resorption along with a periosteal reaction in the cortex. The mean percentages of bone-to-implant contact (21.5%) and bone density (28.1%) near the implant surface were significantly higher in the high-CS group than in the control group (P<0.05), as was the number of Haversian canals (by 5.3). Conclusions: Host modulation by increasing the CS level may enhance the osseointegration of dental implants placed under conditions of impaired bone healing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.138-141
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• 2006

Introduction : In recent years, vascularized, i.e., living bone grafts, have been widely applied in the field of oral and maxillofacial surgery, as a method of treatment of congenital or acquired non-unions, and a large defects in mandible. The vascularized fibular graft has been especially used for this purpose because of its shape and mechanical strength. The postoperative hypertrophy of grafted fibula is of particular interest to us. Material and methods : This study was undertaken to determine the volume change(indirect methods) and radiographic appearance of a free vascularized fibular graft as it responds to the mechanical and physiologic features of its new environment. In order to elucidate the long term effect on fibular mass after mandibular reconstruction, change in various method of volume change was utilized as indirect measure of change in long-term. Results : The younger the patient, the more prominent and rapid the hypertrophy of the graft. the hypertrophy of the graft never exceeded the diameter of the recipient bone, except for callus enlargement after stress fracture of the grafted bone. Conclusion : Etiologic explanations for this phenomenon have not been clarified in the previeous literature. some of the factors implicated include a periosteal reaction or new bone formation, as seen at the onset of bone union after a fracture in a child, a reaction to the mechanical loading on the graft and a reaction to the circulatory changes resulting from the grafting procedure.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.23-34
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• 1991

Even if we can recover the function of mastication, pronunciation and esthetic using the fixed or removable prosthesis in the loss of teeth or hard tissue in the oral cavity, we use several kinds of implants in order to solve the problem which can be occured when we can't install the denture because of excessive bone resolution or psychlogical affairs. At present Titanium implant plays a major role in this field and has osseointegrated. And the study on the modern material is going on, that result in developing and using the implant which is coated with HA, bone induced material. In this, I studied histologically the change of the bone tissue which is occured when three kinds of HA coated implants. Such as Integral, Sustain, Biovent implanted into mandible of dog and got a 8-weeks healing period. I got the conclusion as follows: 1. Most of the implant which is covered with serveral kinds of HA coating implant in bone after 8 weeks being implanted and has osseointegrated, partially converted into the connective tissue. 2. Biovent formed the connective tissue in the perforated area of inferior alveolar canal and has osseointegrated.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.80-86
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• 1996

Parathyroid hormone(PTH) is known to stimulate bone resorption and to inhibit bone collagen synthesis. In contrast, as the evidence of stimulation of bone formation by PTH has recently been observed, the study on the role of PTH involved in osteoporosis draws remarkable attention. This study has dealt with the role of alkaline phoshatase(AP), a marker enzyme for bone formation and osteoblast action, Animals(BALS/cmice) were divided into three dietary groups(high and medium Ca and Ca-free) and hormones including PTH, calcitonin(CT), cholecalciferol(citamin D) were i.p. injected. AP in the serum and liver was measured using Sigma 221 alkaline buffer solutions containing 9mM of p-nitrophenyl phoshate. Enzume was reacted at 37$^{\circ}C$ for 10 minutes and the reaction was stopped by 1.8ml of 0.1N NaOH and measured at 410nm. We found that serum and liver AP activity was increased by low dietary Ac. Compared to the control, and serum Ap activity was enhanced by PTH and vitamin D regardless of the dietary Ca. On the other hand, liver AP activity was inhibited by OTH and vitamin D at all levels of dietary Ca. CT inhibited the action of PTH and vitamin D in the serum. But, the inhibition of PTH and vitamin D action by CT was not observed in the liver, unlike in the case of serum.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.557-564
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• 2000

The bone graft materials can be grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Much care was given to other bone graft materials away from autogenous bone due to its additional operation for harvesting, delayed resorption and limitation of quantity. Demineralized freeze-dried bone(DFDB) and hydroxyapatite are the representatives of bone graft materials. As resorbable hydroxyapatite is developed in these days, the disadvantage of nonresorbability can be overcome. So we planned to study on the strength and the bone formation at the rats calvarial defects of DFDB graft and those of the composite graft with DFDB and resorbable hydroxyapatite. We used the 16 male rats weighting range from 250 to 300 gram bred under the same environment during same period. After we made the 6mm diameter calvarial defect, we filled the DFDB in 8 rats and DFDB and resorbable hydroxyapatite in another 8 rats. We sacrificed them at the postoperative 1 month and 2 months with the periostium observed. As soon as the specimens were delivered, we measured the compressive forces to break the normal calvarial area and the newly formed bone in calvarial defect area using Instron(Model Autograph $S-2000^{(R)}$, Shimadzu, Japan). The rest of the specimens were stained with H&E(Hematoxylin & Eosin) and evaluated with the light microscope. So we got the following results. 1. In every rats, there was no significant difference between the measured forces of normal bone area and those of the bone graft area. 2. In 1 month, the measured forces at DFDB graft group were higher than those of the DFDB and resorbable hydroxyapatite composite graft group(P<0.05). 3. In 2 months, there was no significant differences between the measured forces of DFDB graft group and those of the DFDB and resorbable hydroxyapatite composite graft group. 4. In lightmicroscopic examination, most of the grafted DFDB were transformed into bone in 1 month and a large numbers of hydroxyapatite crystal were observed in DFDB and resorbable hydroxyapatite composite graft group in 1 month. 5. Both group showed no inflammatory reaction in 1 month. And hydroxyapatite crystals had a tight junction without soft tissue invagination when consolidated with newly formed bone. 6. In both groups, newly formed bone showed the partial bone remodeling and the lamellar bone structures and some of reversal lines were observed in 2 months. From the above results, it is suggested that DFDB and resorbable hydroxyapatite composite graft group had a better resistance to compressive force in early stage than DFDB graft group, but there would be no significant difference between two groups after some period. And it is suggested that the early stage of bone formation procedure of DFDB and resorbable hydroxyapatite composite graft group was slight slower than that of DFDB graft group, but there would be no significant difference between two groups after some period.

• Journal of Environmental Health Sciences
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• v.4 no.1
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• pp.34-36
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• 1977

In the examination of leucocyte peroxidase reaction, almost methods were used by benzidine, but it was becoming clear carcinogen. In this study was carried out by comparative Osgood and Asworth method with modified Kaplow method by use of 3-amino-9-ethyl carbasol, In the result, Osgood and Asworth method and new modified Kaplow method in the periperal blood cells (r=0.957) and bone marrow cells (r=0.972) were high correlation.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.563-570
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• 2005

The purposes of this study are to examine a field test on heavy metal removal efficiency for AMD(Acid Mine Drainage) using fish bone and apatite, and to compare those results of the laboratory & the field tests. The duration of the field test was about one month and flow rates of AMD varied from 2.53 l/min to 12.8 l/min. From the result of the field test, removal efficiencies of apatite and those of fish bone are high for As, Fe, and Pb while those of fish born is higher than those of apatite far Al, Cd, Cu and Zn which are similar to the result of the previous laboratory test. In particular, average arsenic removal efficiency of apatite is higher$(84\%)$ than that of fish bone$(75\%)$ like the result of the previous laboratory test. In case of precipitates of phosphate compounds which are generated from chemical reaction between apatite/fish bone and AMD, those generated from apatite/AMD reactionform powder-shape while those created from fish bone/AMD reaction seem to be sludge. Therefore, apatite will be used as a precipitant for mine drainages having wide range of pH based on previous studies while fish bone will be applied as a precipitantfor AMD having lower PH and high concentration of heavy metals.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.54-62
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• 2011

This study was undertaken to investigate the effects of bone waste on the conservation of nitrogen in aerobic composting process by inducing the struvite crystallization, which was known as a powerful method for conservation of nitrogen in composting reaction. Bone waste was dried at oven and crushed to less than 3 mm prior to use. It was found phosphorus content in bone waste was about 20.9% of the fixed solids from the leaching experiments using sulfuric acid. Addition of seed compost affected the progress of composting reaction substantially. In case seed compost was not used, the duration of initial low pH was greater than seed compost was added. This prolonged acidic pH may have a beneficial effect on the leaching of P from the bone waste and struvite crystallization. The struvite crystallization and resulting conservation of nitrogen by addition of bone waste was confirmed by both reduction in ammonia loss and increased ammonia content in compost. However the level of struvite crystallization observed with bone waste addition may be less than the cases water-soluble phosphate salts were used.

• Journal of Ginseng Research
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• v.44 no.6
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• pp.823-832
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• 2020

Background: The formation of a nanotube layer on a titanium nanotube (N-Ti) plate facilitates an active reaction between bone cells and the material surface via efficient delivery of the surface materials of the dental implant into the tissues. Studies have reported that Korean Red Ginseng extracts (KRGEs) are involved in a variety of pharmacological activities: we investigated whether implantation with a KRGE-loaded N-Ti miniimplant affects osteogenesis and osseointegration. Methods: KRGE-loaded nanotubes were constructed by fabrication on pure Ti via anodization, and MC3T3-E1 cells were cultured on the N-Ti. N-Ti implants were subsequently placed on a rat's edentulous mandibular site. New bone formation and bone mineral density were measured to analyze osteogenesis and osseointegration. Results: KRGE-loaded N-Ti significantly increased the proliferation and differentiation of MC3T3-E1 cells compared with cells on pure Ti without any KRGE loading. After 1-4 weeks, the periimplant tissue in the edentulous mandibular of the healed rat showed a remarkable increase in new bone formation and bone mineral density. In addition, high levels of the bone morphogenesis protein-2 and bone morphogenesis protein-7, besides collagen, were expressed in the periimplant tissues. Conclusion: Our findings suggest that KRGE-induced osteogenesis and osseointegration around the miniimplant may facilitate the clinical application of dental implants.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.35-48
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• 2004

Since the occlusal loading is transmitted to the surrounding bone, the success of an implant treatment is closely related to the distribution of the stress on the implant. The finite element analysis method is often used in order to produce a model for dispersion of stress. Assessment of the success of the implant is usually based on the degree of osseointegration which is a bone and implant surface interface. Implant used in this research was designed through the method of shape optimization after the stress on implant was anaylzed by the finite element analysis method. This study was pertinently assessed by a clinical, histologic, histomorphometric analysis after the shape optimized implant was installed on beagle dog tibia. The results are as follows 1. It clinically showed a good result without mobility and imflammatory reaction. 2. Implant was supported by dense bone and bone remodeling showed on the surrounding area of the implant 3. The average percentage of bone-implant contact was 58.1%.The percentage of bone density was 57.6%. Having above results, shape optimized implant showed the pertinence through clinical and histologic aspects. However, to use the shape optimized implant, the further experiment is required for finding problems, improvement.