• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.267-284
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• 1991

Since the concept of a direct contact between bone and implants, without interposed soft- tissue layers, was reported by Dr. $Br{\aa}nemark$, there has been increasing necessity for correct under-standing of bone-implant interface and surrounding tissue response. Beside quality of bone, surgical technique, load applied to implants, one must consider implant materials, design and surface characteristics to obtain osseointegration. In this study HA plasma-sprayed implants, TPS implants and $Al_2O_3$ implants were inserted into the alveolar bone of dog and tissue response was observed with radiograph, stereoscope, light microscope, and scanning electron microscope. Results were as follows : 1. There was rapid and active bone formation in the region adjacent to HA plasma-sprayed implants but in the deep supporting bone only slight bone formation was seen. 2. There was considerable lamella bone formation in the region adjacent to TPS implants and the deep supporting bone became more compact. 3. There was some gap and sclerosing bone formation in the adjacent region of $Al_2O_3$ implants, but there was irregular new bone formation in the deep supporting bone. Therefore, it seems that $Al_2O_3$ is not adequate for osseointegrated implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.101-116
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• 1989

Proplast and Porous Polyethylene which have porous structures as low-modulus polymers have been recently used in maxillofacial plastic and reconstructive surgery. The purpose of this study was to compare the response of adajacent tissue, new bone formation and stability after augmentation by differen methods of subperiosteal graft using proplast and purous polythylene in rabbit mandible. The augmentation procedure was carried out by dividing into two groups, A and B. A group consisted of subperiosteal graft on the cortex, and the other B group was made up only graft following artificial decortication in the mandibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and light microscopic examination. The samples extracted at the 6th postgrafting week were also used for biometric testing and scanning electron microscopic examination. The results obtained from this study were as follows : 1. Macroscopically, infection of graft site, deformation and migration of graft material were not observed in all experimental groups. 2. B group showed more rapid and increased bone formation and the greater stability than A group, and tissue response was similar to each other. 3. In the tissue response, macrophages and cellular infiltrations were observed in Proplast group, but few in PHDPE group. 4. In bone formation of A group, Proplast group showed no bone formation until the 8th week, but PHDPE group showed small quantity of osteoid tissue from the 2nd week and appositional bone growth with new bone formation at the 8th week. 5. In bone formation of B group, both Proplast and PHDPE group showed bone formation, but PHDPE group showed more rapid and larger bone formation. 6. In pattern of bone formation, Proplast group mainly showed appositional bone growth pattern connected with graft site. On the other hand, PHDPE group showed mixed pattern of new bone formation in the pore connective tissue with appositional bone growth from graff site. 7. The maximum mean values of shear stress were serially $111.3gf/mm^{2}$ in PHDPE of B group, $84.8gf/mm^{2}$ in PHDPE of A group, $32.9gf/mm^{2}$ in Proplast B group, and $15.7gf/mm^{2}$ in Proplast of A group. From above results, It was suggested that the capacity of bone formation and stability between bone and graft material were dependent on the pore size and structure of graft material itself, the state of graft site and tissue response.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.651-671
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• 2003

The influence of calcium phosphate (Ca-P) coating on the bone response of titanium implants was investigated two types of titanium implants, i.e. as -machined ,as -machined with Ca-P coating, were prepared. The Ca-P coating produced by OCT Inc technique. These implants were inserted into the left and right femur of beagle dog, After implantation periods of 3 days, 1weeks, weeks, 4weeks, 8weeks, 12weeks. 24weeks, the bone-implant interface was evaluated histologically, histomorphometrically , and removal torque. Histological evaluation revealed no new bone formation around different implant materials after 2weeks of implantation. After 4 weeks, Ca-P coated implants showed a higher amount of bone contact than either of the non coated implants. After 12weeks, bone healing was almost completed. And implant were removed by reverse torque rotation with torque-measuring device. Mean torque values for 4weeks control were 2.375Kgf.cm and experimental were 2.725Kgf.cm. And mean torque values for 8weeks control were 1.25Kgf.cm and experimental were 1.0Kgf.cm On the basis of these findings, we concluded that deposition of a Ca-P coating on an implant has a beneficial effect on the bone response to this implant during the healing phase. Besides implant surface conditions the bone response is also determined by local implant site condition.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.325-331
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• 1999

We tested the bone regenerating capacity and histologic response of bioresorbable matrix-type implant, which was made with Poly(lactide-co-glycolide)(PLGA) and bone apatite for the carrier of bone morphogenetic protein(BMP). The critical size defect of 8mm in diameter was created at the calvaria of SD rats(n=18), and repaired with polymer implant with $15{\mu}g$ of rhBMP-2(n=9) or without it(n=9). At 2 weeks, 1 months after implantation, the animals were sacrificed(3 animals at every interval and group) and histologically evaluated. The calvarial defect which was repaired with polymer with BMP healed with newly formed bone about 70% of total defect. But that without BMP showed only 0 to under 30% bony healing. Inflammatory response was absent in both group through the experimental period, but there's marked foreign body giant response though it was a little less significant in polymer with BMP group. As the polymer was resorbed, the space was infiltrated and replaced by fibrovascular tissue, not by bone. In conclusion, our formulation of bioresorbable matrix implant loaded with bone morphogenetic protein works good as a bone regenerating material. However, it is mandatory to devise our system to have better osteoinductive and osteoconductive property, and less multinucleated giant cell response.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.3
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• pp.245-253
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• 1992

To evaluate the tissue response of demineralized and undimineralized xenogeneic bone-martrix graft in extraskeletal site, we prepared human bone as a implant matrix, and outbred mouse as a recipient. Before clinical application of bank bone of human in Wonkwang university, we should confirm the allogeneic bone grafts us a biologically useful bone graft substitutes, obtanined from the patients receiving oral and maxillofacial surgery. The clinical evaluation and histologic studies showed that both (demineralized and undemineralized) xenogeneic bone matrix grafts were not rejected and that they seemed to stimulate new bone formation at the transplanation site. Undemineralized xenogeneic bone marb6 grafts showed minimal bone induction and gradual demineralization with slow resorption and showed that the differentiation of cells showing fibroblastic activity adjacent to the sop tissue were slowly and less frequently than demineralized bone. Characteristical differences between the demineralized and undemineralized matrix were the appearance of foreign body giant cells (multinucleated giant cells) and the evidence of sloe resorption in undemineralized bone matrix.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.33-45
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• 2001

Objectives: This experimental study was carried out to prove the effect of Saenghyuldan(SHD; shengxiedan) on bone marrow failure induced by cyclophosphamide(CY) and irradiation in mice. Methods: The following were performed; immunopathology, histopathlogical findings of bone marrow and in the smear of myelocyte. hematopoietic cytokine(IL-3, GM-CSF, TPO), hematopoietic stem cell colony assay, humoral immunity(LPS mitogen response), cell-mediated immunity (Con A mitogen response) and nonspecific immunity(macrophage adherence & phagocytosis) in vitro or vivo. Results: SHD showed a protective effect on bone marrow failure induced by cyclophosphamide(CY) and irradiation in mice. SHD increased lymphoproliferative responses to LPS and Con A, and activated macrophage adherence and phagocytosis to SRBC. Conclusions: We expect that SHD can be used to treat bone marrow failure and immune suppression induced by the chemotherapy or radiation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.1
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• pp.30-35
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• 2011

Introduction: Dental implants are used routinely with high success rates in generally healthy individuals. By contrast, their use in patients with diabetes mellitus is controversial because altered bone healing around implants has been reported. This study examined the bone healing response around titanium implants placed immediately in rats with controlled and uncontrolled diabetes. Materials and Methods: Twenty rats were divided into the control, insulin-treated and diabetic groups. The rats received streptozotocin (60 mg/kg) to induce diabetes; animals in the insulin-treated group also received three units of subcutaneous slow-release insulin. A titanium implant ($1.2{\times}3\;mm$) was placed in the extraction socket of the maxillary first molar and bone block was harvested at 1, 2 and 4 weeks. Results: Bone formation around the implants was consistently (from 1 to 4 week post-implantation) slower for the diabetic group than the control and insulin-treated group. Bone morphogenesis in the diabetic rats was characterized by fragmented bone tissues and extensive soft tissue intervention. Conclusion: The immediate placement of titanium implants in the maxilla of diabetic rats led to an unwanted bone healing response. These results suggest that immediate implant insertion in patients with poorly controlled diabetes might be contraindicated.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.412-422
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• 2002

The use of biochemical markers of bone turnover may be particular interest in the investigation of bone disorders with osteoporosis. Serum osteocalcin(OC), total alkaline phosphatase and procollagen C, reflecting bone formation, and urinary pyridinium cross-links excretion, reflecting bone reabsorption have been measured in hyperthyroidism, postmenopause women, after testosterone supplementation, androgen, testosterone and estrogen deficiency, bone mineral density degree, age duration. Bone marks which is reflect to metabolic bone disorders are biochemical indices method to measure enzyme activity about bone formation, bone absorption and bone components in blood or urine. Bone metabolism biochemical marks are correlated with osteophorotic agents and also represent significantly different between bone mineral density and bone biochemical marks. Therefore if we develope and use bone metabolism marks which have higher sensitivity and specificity in bone formation and bone absorption, I think that these bone biochemical marks can have utility in the clinical application to predict osteoporosis risk group, bone loss, bone fracture and response degree to treatment of osteoporosis risk groups.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.1-8
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• 1975

Despite a number of recent studies on appendix its function appears to remain unknown. The present studies were undertaken in order to extend and confirm the previous studies concerning the role of appendix in immune response. An early hemagglutinin response of mercaptoethanol sensitive antibody(IgM antibody) in rabbit injected intravenously(i.v.) with 200mcg of bovine gamma globulin(BGG) was abolished by lethal whole body irradiation(900 r), but preserved in animals whose appendix and bone marrow were shielded during irradiation. Late formation of mercaptoethanol resistant antibody(IgG antibody) and the development of memory in bone marrow shielded animals were not affected by irradiation of the appendix. Formation of either IgM or IgG antibody to sheep red blood cells(SRBC) injected i.v. as determined by direct plaque forming cell(DPFC) technique in spleen were effectively abolished by appendectomy, thymectomy, or both followed by irradiation. When bone marrow was shielded in combination with autologous appendix reconstitution, DPFC response was about 5 times greater than the sum of two. Lysed appendix cells failed to restore the response. Lethally irradiated rabbits restored with combination of autologous appendix and thymus cells showed DPFC responses which were essentially normal. Three pools of appendix were obtained by manual separation technique and were stimulated with soluble concanavalin A(Con A), phytohemagglutinin-P(PHA) and pokeweed mitogen(PWM). Rabbit appendix cells responded to Con A, PHA and PWM. Cells of thymus dependent area(TDA) of the appendix were relatively enriched in their response to T cell mitogens compared to dome and follicle cells. The PHA/Con A responsive ratio of appenix TDA subpopulation was high, indicating that Con A responsive cells have a wider distribution among appendix. This finding showed that interfollicular area of the appendix is thymus-dependent. The present studies confirmed other evidence that the rabbit appendix cells itself are unable to form antibody and T lymphocytes in appendix TDA may be heterogenous, and that the appendix cells are synergistic with either bone marrow or thymus cells in the early hemagglutinin on splenic antibody response to BGG or SRBC.

• Journal of Biomedical Engineering Research
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• v.41 no.1
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• pp.22-27
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• 2020

Auditory stimuli are commonly used in various electroencephalogram experiments, also in EEG-based brain-computer interface systems. However, using conventional earphones that blocks the ear canal attenuates or even blocks external environmental sound which might cause loss of crucial information from surroundings. Instead, bone-conductive earphones are able to deliver sound through vibration without blocking the ear canal. To investigate the feasibility of the bone-conductive earphones for auditory-stimuli based experiments, we compared N100 event-related potential features as well the event-related spectral perturbation and inter-trial coherence of auditory steady-state response between conventional and bone-conductive earphones. The results showed no significant differences between bone conduction and conventional earphones regardless of distinct sound pressures. This result shows that bone conductive earphones can be used for auditory experiments when the environmental sound is crucial to the user.