• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.83-90
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• 2008

Purpose: This study investigated the osteoconductivity of natural calcium carbonate-derived bone substitutes, hen eggshell (ES), and compared with those of commercial bone substitutes. Materials and Methods: Osseous defects created in the rat calvaria were filled with particulated ES(ES-1), ES with calcium-deficient hydroxyapatite surface layer (ES-2), Biocoral(Inoteb, France), and Bio-Oss(Geistlich Pharma, Wolhusen, Switzerland). After 4 and 8 weeks of healing, histomorphometic analysis was performed to evaluate the amount of newly formed mineralized bone area (NB%). Results: Histologic and histomorphometric analysis showed new bone formation and direct bony contact with the grafted materials in all groups. At 4 weeks, Biocoral group showed greater NB% compared to Bio-Oss and ES-1 groups (P<0.05). At 8 weeks, Biocoral and ES-2 groups showed significantly greater NB% compared to Bio-Oss group (P<0.05). Conclusion: These results indicate that natural calcium carbonate-derived bone substitutes with microporous calcium-deficient hydroxyapatite surface layer may be an effective materials treating osseous defects.

• Journal of Periodontal and Implant Science
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• v.34 no.4
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• pp.759-769
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• 2004

Periodontal therapy has dealt primarily with attempts at arresting progression of disease, however, more recent techniques have focused on regenerating the periodontal ligament having the capacity to regenerate the periodontium. The effect of chitosan, a carbohydrate biopolymer extracted from chitin, on periodontal ligament regeneration is of particular interest. The purpose of this study was to evaluate the effect of chitosan on the expression of extracellular matrix proteins in primary rat calvarial cells in Vitro. In the control group, cells was cultured with BGjb media. In the experimental groups, cells were cultured with chitosan in concentration of 0.01, 0.1, 1.0 and 2.0 mg/ml. Then each group was characterized by examining alkaline phosphatase activity at 3 and 7 days, and the ability to produce mineralized nodules of rat calvarial cells at 14 and 21 days. Synthesis of type I collagen (COL-I), osteocalcin (OCN), bone sialoprotein (BSP) was evaluated by RT-PCR at 14 days. The results were as follows: 1. Alkaline phosphatase activity was significantly higher in the concentration of chitosan 0.01mg/ml, 0.1mg/ml and 1.0mg/ml compared to control (p<0.05). 2. The percentage of mineralized bone nodule was more in the concentration of chitosan 0.1mg/ml and 1.0mg/ml than the control. 3. At 14 day culture, the expression of OCN was increased by chitosan in concentration of 1.0 mg/ml and 2.0 mg/ml. These results suggested that chitosan in concentration of 0.1 and 1,0 mg/ml stimulate the extracellular matrix of primary rat calvarial cells and may facilitate the formation of bone.

• The Journal of Korean Obstetrics and Gynecology
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• v.26 no.2
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• pp.1-16
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• 2013

Objectives: This study was performed to evaluate the effect of Dokhwalgisaengtang-gami water extract(DGG) on osteoporosis. Methods: The osteoclastogenesis and gene expression were determined in RANKL-stimulated RAW 264.7 cell. And osteoblastogenesis was also determined in rat calvarial cell. Results: The results were summarized as followes. 1. DGG decreased the number of TRAP positive cell in RANKL-stimulated RAW 264.7 cell. 2. DGG inhibited TRAP activity in RANKL-stimulated RAW 264.7 cell. 3. DGG decreased the expression of NAFTc1, MITF in RANKL-stimulated RAW 264.7 cell. 4. DGG increased the expression of iNOS, COX-2, IL-6 in RANKL-stimulated RAW 264.7 cell. 5. DGG decreased the expression of cathepsin K, MMP-9, TRAP in RANKL-stimulated RAW 264.7 cell. 6. DGG increased cell proliferation of rat calvarial cell. 7. DGG increased ALP activity in rat calvarial cell 8. DGG increased bone matrix protein, collagen synthesis and nodule formation in rat calvarial cell. Conclusions: It is concluded that DGG might decrease the bone resorption resulted from decrease of osteoclast differentiation and it's related gene expression. And DGG might increase the bone formation resulted from increase of osteoblast function.

• Journal of the Korean Society of Radiology
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• v.2 no.4
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• pp.41-46
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• 2008

Computed tomography (CT) is a medical imaging method employing tomography. CT is a 3-Dimensional (3-D) radiographic imaging technique, which is not suited for assessment of inflammation, but can be considered a reference method for assessment of bone damage, due to its direct 3-D visualization of calcified tissue. In this study of pathological joint changes in a rat model of adjuvant-induced arthritis (AIA) and quality analysis of bone destructions were performed by 3-Dimensional computed tomography images. These data demonstrate that the destructive progression of disease in a rat AIA model can be quantified using 3-D CT image analysis, which allows assessment of arthritic disease status and efficacy of experimental therapeutic agents.

• Advances in Traditional Medicine
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• v.6 no.2
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• pp.79-85
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• 2006

In order to study the effect of acupuncture stimulation on bone mineral density (BMD), using the ovariectomized (OVX) rat model, we assessed the degree of osteopenia by dual-energy X-ray absorptiometry, measured the level of locomotor activity using a metabolism measuring system, and performed histological studies of bone tissue. Twenty-four female Wistar rats (8 weeks old, 160 - 180 g)were divided into three groups. Rats in the OVX-A group underwent ovariectomy followed by acupuncture stimulation. The OVX rats in the Vehicle control group were not treated with acupuncture as a control. The rats in the control group received neither ovariectomy nor acupuncture. Acupuncture stimulation for 12 weeks in the OVX-A group inhibited the reduction in BMD of the femoral bones caused by ovariectomy. Moreover, in the two OVX groups, there was no clear difference in the level of locomotor activity between the active and resting phases prior to acupuncture stimulation in each rat, and the pattern of locomotor activity was irregular. After acupuncture stimulation of the OVX-A rats, the pattern of locomotor activity became diphasic with clear active and resting phases, as was observed in the Control group. On histological studies, the continuity of trabecular bone was maintained more favorably and bone mass was higher in the OVX-A group than in the vehicle control group. These results suggest that the increased locomotor activity that had been induced by acupuncture stimulation increased the BMD.

• The korean journal of orthodontics
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• v.44 no.5
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• pp.263-267
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• 2014

Objective: To three-dimensionally elucidate the effects of occlusal hypofunction on the periodontal ligament and alveolar bone proper of rat molars by micro-computed tomography (micro-CT). Methods: Occlusal function in the molar area was restricted by attaching an anterior bite plate on the maxillary incisors and a metal cap on the mandibular incisors of 5-week-old male Wistar rats for 1 week. The periodontal ligament space and alveolar bone proper around roots of the mandibular first molar were assessed by histology and micro-CT. Results: The periodontal ligament space was narrower and the alveolar bone proper was sparser and less continuous in the hypofunction group than in the control group. Further, both the volume of the periodontal ligament and the volumetric ratio of the alveolar bone proper to the total tissue in the region of interest were significantly lower in the hypofunction group (p < 0.05). Conclusions: Occlusal hypofunction induces atrophic changes in the periodontal ligament and alveolar bone proper of rat molars.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.37-55
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• 1989

The tissue reactions concerned in alveolar bone remodelling at the pressure zones of rat molar periodontium associated with the application of force (15 gm) to the maxillary first molar teeth of the albino rats were studied by the transmission electron microscopy. Osteoclasts referrable to bone resorption were observed thereafter 3 hour survival period and undermining resorption was generated thenceforth 2 day survival period. Bone resorption, reversal zone and new bone formation were simultaneously observed adjacent to the zone of undermining resorption in the 7 day survival period. Osteoclasts with well developed primary lysosome, ruffled border, clear zone, granules and Golgi apparatus were detected at the zone of the bone resorption, and dark and bright cells adjacent to the osteoclasts as well. Mononuclear cells and perpendicularly arranged collagenous fibers were observed in the reversal zone and, on the other hand, osteoblasts with well developed Golgi apparatus and rough endoplasmic reticulum were detected at the zone of bone formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.1-8
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• 2005

This study was aimed to characterize osteogenic potential of rat bone marrow stromal cells (BMSC) isolated with standard flushing method and investigate the plasticity of transdifferentiation between osteoblastic and adipocytic lineage of cultured BMSC. Unlike aspiration method in human, rat bone marrow was extracted by means of irrigation with culture media that elevates the possibility of co-extraction of committed osteoprogenitor, or preosteoblast or other progenitor cells of several types present inside bone marrow. The cultured stromal cells showed high ALP activity which is representative marker of osteoblast without any treatment. Osteogenic inducers such as Dex and BMP-2 were examined for the evaluation of their effect on osteogenic and adipocytic differentiation of stromal cells, because they function as osteoinductive agent in stromal cells, but simultaneously induce adipogenic differentiation. Osteogenic differentiation was evaluated by measuring alkaline phosphatase activity or mRNA expression of osteoblast markers such as osteopontin, bone sialoprotein, collagen type I and CbfaI, and in vitro matrix mineralization by von Kossa staining. Oil red staining method was used to detect adipocyte and adipocytic marker, aP2 and $PPAR{\gamma}2$ expression was examined using RT-PCR. It can be supposed that irrigation procedure resulted in high portion of already differentiation-committed osteoprogenitor cell showing elevated ALP activity and strong mineralization only under the supplement of $100{\mu}M$ ascorbic 2-phosphate and 10mM ${\beta}$-glycerophosphate without any treatment of osteogenic inducers such as Dex and BMP-2. Dex and BMP-2 seemed to transdifferentiate osteoprogenitor cells having high ALP activity into adipocytes temporarily, but continuous treatment redifferentiated into osteoblast and developed in vitro matrix mineralization. This property must be considered either in tissue engineering for bone regeneration, or in research of characterization of osteogenic differentiation, with rat BMSC isolated by the standard irrigation method.

• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.174-175
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• 2005

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.923-939
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• 1997

This study was performed to evaluate the effect of mixed culture of rat's calvaria cells and periodontal ligament cells on calcification. These cells have been known to do important role on the periodontal tissue regeneration, especially alveolar bone and cementum. Experimental groups were made which based on the different rate of rat's calvaria cells and periodontal ligament cells, and then these cells were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, $50{\mu}g/ml$ ascorbic acid, and 10mM/ ml $Na-{\beta}-glycerophosphate$. Each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity, and the number of calcified nodules in vitro. In cell proliferation rate , the cells of control groups were cultured Dulbecco's Modified Eagle's Medium contained with 10 % fetal bovine serum. The results were as follows : 1. The cell proliferation rate in control groups decreased stastically significantly along with the decrease of the rate of bone cells at 7 day and 20 day(P < 0.01). 2. The cell proliferation rate in experimental groups decreased stastically significantly along with decrease of the rate of bone cells at 3 day and 14 day(P < 0.01). 3. The amount of total protein synthesis was significantly decreased along with decrease of the rate of bone cells at 3 day and 6 day(p < 0.01). 4. Alkaline phosphatase activity showed reverse time dependent pattern and was significantly decreased along with decrease of the rate of bone cells during the experimental periods (P < 0.01). 5. Calcified nodules were observed in group 1 (Rat calvaria cells alone) for the first time, and the number of calcified nodule decreased stastically significantly along with the decrease of the rate of bone cells at 12 day(P < 0.01). From the above results, When bone cells and periodontal ligament cells were mixed cultured, the cell proliferation rate was mostly dependent on the actual rate of bone cells and same pattern was showed in amount of total protein synthesis, alkalinephosphatase activity, and the number of calcified nodules. And the calcified nodule forming capacity of bone cells was inhibited by periodontal ligament cells