• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.939-948
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• 2005

The role of the periosteum on osteointegration of $Bio-Oss^{(R)}$(Geistlich, Wolhusen/Switzerland) was studied in rabbit calvarial defect. 12 New Zealand white male rabbits between 2.8 and 4 kg were included in this randomized, blinded, prospective study. Each rabbit was anesthetized with Ketamine HCl(5 mg/kg) and Xylazine HCl(1.5 ml/kg). An incision was made to the bony cranium and the periosteum was reflected. Using a 6-mm trephine bur(3i. USA), four 8-mm defects were created with copious irrigation. The defects were classified into barrier membrane($Tefgen^{(R)}$, Lifecore Biomedical. Inc, U.S.A.) only group as a control, $Bio-Oss^{(R)}$ with barrier membrane group, $Bio-Oss^{(R)}$ with periosteum covering group, and $Bio-Oss^{(R)}$ without periosteum covering group. There were 2 rabbits in each group. The wound was closed with resorbable suture materials. Rabbits were sacrificed using phentobarbital(100 mg/kg) intravenously at 1, 2, and 4 weeks after surgery. The samples were fixed in 4% paraformaldehyde, and decalcified in hydrochloric acid decalcifying solution(Fisher Scientific, Tustin, CA) at $4^{\circ}C$ for 2-4 weeks. It was embedded in paraffin and cut into 6 ${\mu}m$ thickness. The sections were stained with H & E and observed by optical microscope. The results were as follows; 1. The periosteum played an important role in osteointegration of $Bio-Oss^{(R)}$ in bone defects. 2. When the periosteum remained intact and $Bio-Oss^{(R)}$ was placed on the defect, $Bio-Oss^{(R)}$ with periosteum covering has been incorporated into the newly formed bone from 2-week postoperatively. 3. When the periosteum was removed at the surgical procedure, invasion of connective tissue took place among the granules, and new bone formation was delayed compared to periosteum covering group. Therefore, when the bone grafting was performed with periosteal incision procedure to achieve tension-free suture, the integrity of the overlying periosteum should be maintained to avoid fibrous tissue ingrowth.

• The Journal of the Korean dental association
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• v.56 no.12
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• pp.667-685
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• 2018

Objectives: Aim of this study was to evaluate bone regenerative efficacy of a chemically cross-linked porcine collagen membrane (CM) when used in combination with highly soluble biphasic calcium phosphate (BCP). Materials and methods: Physiochemical properties of the experimental collagen membrane were analyzed. Four circumferential defects with diameter of 8 mm were created in each calvarium of New Zealand white rabbits (n = 10). Defects were randomly allocated to one of following 4 groups: 1) BCP-CM (BCP (20% hydroxyapatite/80% ${\beta}$-tricalcium phosphate) covered with the prepared collagen membrane), 2) BCP (only BCP used), 3) CM (only the prepared collagen membrane used), and 4) C (control; only blood clot). After 2 weeks (n = 5) and 8 weeks (n = 5), histologic and histomorphometric analyses were performed. Results: The experimental collagen membrane exhibited dense and compact structure, relatively high tensile strength and lower degradability. Histologic analyses revealed that new bone increased rapidly at 2 weeks, while defect was preserved at 8 weeks. Histomorphometric analyses revealed that the new bone areas increased in the BCP-grafted groups over 8 weeks, with BCP-CM exhibiting greater total augmented area than that of BCP group both at 2 weeks ($27.12{\pm}3.99$ versus $21.97{\pm}2.27mm^2$) and 8 weeks ($25.75{\pm}1.82$ versus $22.48{\pm}1.10mm^2$) (P < 0.05). Conclusions: The experimental collagen membrane successfully preserved localized defect for 8 weeks despite early rapid resorption of BCP. Within the study limitations, combined use of the chemically cross-linked porcine collagen membrane and highly soluble BCP aided localized bone regeneration.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.132-138
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• 2010

Purpose: The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancellous human bone substitutes on calvarial defects of rabbits. Methods: Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation. Results: In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups. Conclusions: Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.35-39
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• 1992

SMZ is one of the most widely used antibacterial agents in veterinary medicine. It is also used as a growth promotant in many species of domestic animals There are marked species differences in its metabolism and pharmacokinetics. However, its pharmacokinetic and metabolism in rabbits. which are ragarded not only as good laboratorty animals hut also as good economical animals in its own, are lacking. Sex-differences in drug metabolism are well recognized in wide range of animal species including rats. Males are known to he more active than females. It is also know that there are Significant differences in the direction of metabolic pathways. But recently, female goats are reported to be more active in the metabolie capacity of SMZ than the other sex by Dutch researchers at Utrecht. Therefore, it is not easy to make general conclusicn of having higher SMZ metal-die capacity in the male compared to the opposite sex in every animal species. In this regard, the study on metabolic pattern of SMZ in rabbits, which are regarded as hervivorous, is of interest because the dietary habbits of rabbit are comparable to thai of goal, NEW Zealand White rabbits of each sex were given SMZ(35mg/kg) as a bolus injection into the marginalean, vein in order to study its pharmacokinetic profiles(using plasma) anc metabolic pattem(24h urine) as specified in the methods anc materials. 1. In the rabbit, the major metabolic pathway of SMZ was the acetylation(the formation of $N_4AcSMZ$). There were hydroxylation pathways(50HSMZ, $6CH_2OHSMZ$) as well, in the metabolism of SMZ in the rabbit, but minor pathways. 2. No sex differences in the metabolic direction of SMZ and its metabolites formation were found from the urinary excreted metabolites of SMZ out of 24h collected urine. 3. The concentration-time curves of SMZ(35mg/kg, iv) in the plasma compartment were fitted to a one-compartment open model when using a computer program(NONLIN). There was also no difference in the pharmacokinetic pattem of SMZ between two sexes. 4. The emergence of $N_4AcSMZ$ metabolized from SMZ was very fast in the plasma of the rabbit The elimination of $N_4AcSMZ$ was prolonged as compared to that of the parent drug Vie found no sex difference in the elimination pattern of $N_4AcSMZ$ in the rabbit.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.531-536
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• 1994

Background: The intrapleural instillation of tetracycline for pleural sclerosis had been most commonly used in patients with symptomatic malignant pleural effusion or recurrent pneumothorax for a long time. Unfortunately, at a time of expanding use of this agent, the production of injectable tetracycline hydrochloride used for pleurodesis was discontinued by its sole manufacturer in mid-1991 because the manufacturer was unable to meet US Food and Drug Administration purity standards. So we performed a preliminary study of doxycycline, as a alternative pleural sclerosant on rabbit pleura and compared its efficacy with that of tetracycline. Method: Eighteen New Zealand white rabbits weighing 2 to 3kg(mean 2.6kg) were devided into three groups. In each groups, one tetracycline(20 mg/ml/kg) and two doxycycline solutions(7 mg/ml/kg and 20 mg/ml/kg) instillated into the right pleural space through an 18-gauge angiocath with care to prevent pneumothorax. All rabbits were sacrificed after 28 days. Results: 1) In the group of tetracycline 20 mg/ml/kg(six rabbits), five rabbits showed partial pleural symphysis with several fibrous bands, and one rabbit died on 22th day. 2) In the group of doxycycline 7 mg/ml/kg(six rabbits), three rabbits showed partial pleural symphysis and the other three rabbits showed complete pleural symphysis without necrosis of underlying parenchymal lung tissue. 3) In the group of doxycycline 20 mg/ml/kg(six rabbits), two rabbits showed complete pleural symphysis without lung necrosis, another two rabbits showed complete pleural symphysis with lung necrosis, and the other two rabbits died on 4th and 13th day, respectively. Conclusion: We concluded that doxycycline is a highly effective sclerosing agent having stronger pleurodesis effect with that of tetracycline by dose base and its optimal dosage was considered as 7 mg/ml/kg with minimal complications.

• Journal of Periodontal and Implant Science
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• v.42 no.6
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• pp.204-211
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• 2012

Purpose: This study was performed to establish an experimental rabbit model for single-stage maxillary sinus augmentation with simultaneous implant placement. Methods: Twelve mature New Zealand white rabbits were used for the experiments. The rabbit maxillary sinuses were divided into 3 groups according to sinus augmentation materials: blood clot (BC), autogenous bone (AB), and bovine-derived hydroxyapatite (BHA). Small titanium implants were simultaneously placed in the animals during the sinus augmentation procedure. The rabbits were sacrificed 4 and 8 weeks after surgery and were observed histologically. Histomorphometric analyses using image analysis software were also performed to evaluate the parameters related to bone regeneration and implant-bone integration. Results: The BC group showed an evident collapse of the sinus membrane and limited new bone formation around the original sinus floor at 4 and 8 weeks. In the AB group, the sinus membrane was well retained above the implant apex, and new bone formation was significant at both examination periods. The BHA group also showed retention of the elevated sinus membrane above the screw apex and evident new bone formation at both points in time. The total area of the mineral component (TMA) in the area of interest and the bone-to-implant contact did not show any significant differences among all the groups. In the AB group, the TMA had significantly decreased from 4 to 8 weeks. Conclusions: Within the limits of this study, the rabbit sinus model showed satisfactory results in the comparison of different grafting conditions in single-stage sinus floor elevation with simultaneous implant placement. We found that the rabbit model was useful for maxillary sinus augmentation with simultaneous implant placement.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.321-329
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• 2009

Purpose: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. Methods: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight $3.0{\sim}3.5kg$). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The specimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. Results: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). Conclusions: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human application.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.11.1-11.8
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• 2016

Background: Silk cocoon is composed of multiple layers. The natural silk cocoon containing all layers was cut as a rectangular shape as defined as total group. The inner and outermost layers were removed from the total group and the remained mat was defined as the middle group. The objectives of this study was to compare the total group with the middle group as a barrier membrane for the guided bone regeneration. Methods: The effects of these materials on the cellular proliferation and alkaline phosphatase (ALP) expression of MG63 cells were explored. For comparing bone regeneration ability, bilateral bone defects were created in calvarial areas in ten adult New Zealand white rabbits. The defects were covered with silk membranes of the middle group, with silk membrane of the total group used as the control on the contralateral side. The defects were allowed to heal for 4 and 8 weeks. Micro-computerized tomography (${\mu}CT$) and histological examination were performed. Results: The middle group exhibited a higher MTT value 48 and 72 h after treatment compared to the total group. ALP expression was also higher in the middle group. The results of ${\mu}CT$ and histologic examination showed that new bone formation was significantly higher in the middle group compared to the total group 8 weeks postoperatively (P < 0.05). Conclusions: In conclusion, the middle layer of the silk cocoon supports guided bone regeneration better than unprocessed silk cocoon.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.209-217
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• 2013

The objective of this study was to evaluate the bone regeneration capability of silk membrane plus 3% 4-hexylresorcinol (3% 4-HR plus SM) in a rabbit calvarial defect model. Twenty New Zealand white rabbits were used in this study. Bilateral round shaped defects were created in the parietal bone (diameter: 8.0 mm). And the defects were covered with (1) 3% 4-HR plus SM, (2) collagen membrane (CM), (3) no graft material. After surgery, the animals were sacrificed at 4 weeks and 8 weeks. Bone regeneration was analyzed in each section by micro-computerized tomography (${\mu}$-CT). And Hematoxylin and eosin stains were used for histological analysis. As measured by ${\mu}$-CT analysis 4 weeks after surgery, the average of new bone formation in animals treated with 3% 4-HR plus SM was greater than that of animals treated with CM. and the difference was statistically significant. And well organized lamella bones were observed in the histological view of the 3% 4-HR plus SM group. Therefore, more bone regeneration was seen in animals treated with 3% 4-HR plus SM than in those treated with CM or uncovered control.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.110-119
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• 1999

The principle of guided tissue regeneration (GTR), as applied to bone healing, is based on the prevention of connective tissue from entering the bony defect during the healing phase. This allows the slower bone producing cells to migrate into and reproduce bone within the defect. The principle of guided tissue regeneration has demonstrated a level of success in regenerating bone defect. Several types of membrane barrier, each one with distinct properties, have been utilized to apply this principle in bone regeneration. The purpose of this study is to introduce and discuss the attributes of rubber dam as a barrier membrane and evaluate whether improved bone regeneration can be achieved by GTR using rubber dam. In the 15 New Zealand white rabbits, full-thickness bone defects on three sites of each rabbit calvaria were made. Non membrane group served as a control and experimental group 1 was covered with rubber dam and group 2 covered with Gore-Tex$^{TM}$ membrane. Macroscopic, radiographic, microscopic examinations were made serially on 1, 2, 3, 6, 12 weeks after operation. The results were as follows: 1. Macroscopically, the control site was collapsed and filled with connective tissue throughout the experimental period. But the defects of experimental groups 1 and 2 were filled with bone-like mass and showed the hard consistency on palpation. 2. Radiographically, the early new bone formation appeared similarly from the host bone in groups 1 and 2. 3. Microscopically, there were much connective tissue at the central part of control site but the defect of group 1 and 2 was filled with the mature bony trabeculae on the 12th week. This results suggest that rubber dam can be effectively used as a barrier membrane for guided bone regeneration.