• 대한치과보철학회지
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• 제22권1호
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• pp.33-50
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• 1984

The purpose of this study was to investigate whether the ashed tooth powder is utilized as an alternative material of the implant to recovery the bony defect. For this purpose its biocompatibility was evaluated comparing to the synthetic calcium phosphate compounds, such as Syntograft and Calcitite, as well as the vacuum firing porcelain (Ceramco Inc.) which is anticipated to use as a matrix to aid sintering. Bony defects to exposure the bone marrow, $3{\times}5$ mm in size, were created in the right and left tibias of fifteen rabbits, and then the ashed tooth powder at $950^{\circ}C$, the porcelain powder, Syhtograft and Calcitite were inserted in the defects of twelve rabbits of the experimental group and the blood clot only was filled in the defects of three rabbits of the control group. The experimental and control rabbits were sacrificed at 1st, 2nd 3rd week after implantation and the histologic examination was performed. The ashed tooth powder in order to make the needed form of the implant was molded using the cylindrical mold 1 cm high, 1 cm in diameter under the pressure of $1000kg/cm^2$ and the ashed tooth powder was sintered at $1100^{\circ}C$ for 1 hour and the mixture of the porcelain powder and the ashed tooth powder at the weight ratio of 7:3, 6:4, 5:5, 4:6 were molded in the same manner and were sintered at $925^{\circ}C$. From this sintered material, square shaped implants were prepared in the dimension of $2{\times}4{\times}6mm$. The prepared implants were surgically placed in the subperiosteum of lateral surfaces of the right and left mandibular bodies. The dogs were sacrificed at 4 weeks, and then the specimens were examined using the light and scanning electron microscopes. The results of this study were obtained as follows: 1. Any inflammatory response was not noted after implanting of the ashed tooth powder, Syntograft, Calcitite and the porcelain powder during the whole experimental period after implantation. 2. Induction of the new bone formation was significantly shown in the ashed tooth powder, Syntograft and Calcitite. 3. The more the porcelain powder was contained in the implants, the more the porosity was and the bigger the pore size was under the scanning electron microscope. And there was ingrowing of the fibrous connective and the osteoid tissue. 4. The osteoid tissues were found to be directly fused to the implant of the ashed tooth powder, and the mixture implant of the porcelain powder and the ashed tooth powder at the weight ratio of 4:6 under the light and scanning electron microscopes.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.103-111
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• 2011

Purpose: Choukroun's platelet-rich-fibrin (PRF) is composed of platelets, white blood cells and fibrin matrix. It does not induce enough bone formation by itself but it can improve bone formation with calcium. Silk fibroin does not cause inflammatory reactions because it is bio-compatible and degradable. The purpose of this study was to exam the bone formation when a combination of Choukroun's PRF and silk fibroin was used. Methods: In this study, cell reactions to silk powder with differing molecular weights was first tested to select the appropriate silk powder. Then we applied these bone graft materials on defects of skull and in a peri-implant bony defect model in New Zealand rabbits. The results between the experimental and control s (non-grafted) group were analyzed. Results: The small sized silk fibroin powder showed increased cellular proliferation for bone-regeneration. There was no statistically significant difference between the experimental group and the control group at 6 weeks, but more new bone formation was observed in the combination graft group at 12 weeks (P<0.05). And in the dental implant model, the combination bone graft group showed much improved torque test results, which was statistically significant. Histomorphometric analysis showed more regenerated cortical bone and a higher mean bone to implant in the experimental group. Both were statistically significant. Conclusion: The combination graft of Choukroun's platelet-rich-fibrin (PRF) and silk fibroin powder can successfully restore the bony defects in a skull defected model and a peri-implant bony defects model.

• 해양환경안전학회지
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• 제25권6호
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• pp.708-716
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• 2019

세월호 사고 이후 내항선 분야의 해사안전관리를 강화하기 위하여 해사안전감독관 제도가 도입되었다. 이들은 선박에 대한 정기 및 수시 지도·감독 중 선박의 시설 분야에서 중대한 결함사항이 발견되면 시정이 완료될 때 까지 선박의 항행을 정지하는 행정처분을 하고 있다. 항행정지명령은 내항선박에 대하여 해사안전감독관이 행사하는 강장 강력한 규제행위의 일종이다. 선박의 안전과 해양환경보호를 위한 해사안전감독관에 의한 내항선박의 지도·감독의 중요성은 아무리 강조해도 지나치지 않을 것이다. 그러나 각 지방해양수산청의 선박에 대한 규제의 정도는 이를 집행하는 사람에 따라 다소의 개인차가 있을 수 있으며, 집행과정에서 개인의 고의 또는 과실이 발생할 수가 있다. 지방해양수산청에 의한 선박의 억류는 선박운항 상의 지체를 가져오기 쉽고, 용선계약의 정지에 의하여 선박의 소유자는 많은 경제적 손실을 입을 수 있다. 그럼에도 불구하고 해사안전법에서는 해사안전감독관에 의한 항행정지명령의 행정처분에 대하여 이의신청과 같은 불복절차를 규정하지 않고 있다. 따라서 이러한 문제점을 극복하기 위하여 지도·감독의 근거가 되는 해사안전법 상에 개인의 고의 또는 과실에 의한 부당한 항행정지 행정처분에 대하여 이의신청을 통한 권리의 구제가 가능하도록 제도를 개선해야 한다.

• Journal of Periodontal and Implant Science
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• 제33권1호
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• pp.13-26
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• 2003

Periodontal regeneration therapy with bone-substituting materials has gained favorable clinical efficacy by enhancing osseous regeneration in periodontal bony defect. As bone-substituting materials, bone powder, calcium phosphate ceramic, modified forms of hydroxyapatite, and hard tissue replacement polymer have demonstrated their periodontal bony regenerative potency. Bone-substituting materials should fulfill several requirements such as biocompatibility, osteogenecity, malleability, biodegradability. The purpose of this study was to investigate biocompatibility, osteo-conduction capacity and biodegradability of $Na_2O$, $K_2O$ added calcium metaphosphate(CMP). Beta CMP was obtained by thermal treatment of anhydrous $Ca_2(H_2PO_4)_2$. $Na_2O$ and $K_2O$ were added to CMP. The change of weight of pure CMP, $Na_2O$-CMP, and $K_2O$-CMP in Tris-buffer solution and simulated body fluid for 30 days was measured. Twenty four Newzealand white rabbits were used in negative control, positive control(Bio-Oss), pure CMP group, 5% $Na_2$-CMP group, 10% $Na_2O$-CMP goup, and 5% $K_2O$-CMP group. In each group, graft materials were placed in right and left parietal bone defects(diameter 10mm) of rabbit. The animals were sacrificed at 3 months and 6 months after implantation of the graft materials. Degree of biodegradability of $K_2O$ or $Na_2O$ added CMP was greater than that of pure CMP in experimental condition. All experimental sites were healed with no clinical evidence of inflammatory response to all CMP implants. Histologic observations revealed that all CMP grafts were very biocompatible and osseous conductive, and that in $K_2O$-CMP or $Na_2O$-CMP implanted sites, there was biodegradable pattern, and that in site of new bone formation, there was no significant difference between all CMP group and DPBB(Bio-Oss) group. From this result, it was suggested that all experimental CMP group graft materials were able to use as an available bone substitution.

• Journal of Periodontal and Implant Science
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• 제39권sup2호
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• pp.213-222
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• 2009

Purpose: Recently, interest in chitosan has increased due to its excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. On the other hand, hydroxyapatite is used as a bone substitute in the fields of orthopedics and dentistry. The hydroxyapatite-chitosan (HA-CS) complex containing hydroxyapatite nanoparticles was developed for synergy of both biomaterials. The objective of this study was to evaluate the effect of hydroxyapatite (HA)-chitosan (CS) membrane on bone regeneration in the rat calvarial defect. Methods: Eight-millimeter critical-sized calvarial defects were created in 70 male Sprague-Dawley rats. The animals were divided into 7 groups of 10 animals and received either 1) chitosan (CS) 100% membrane, 2) hydroxyapatite (HA) 30%/CS 70% membrane, 3) HA 30%/CS 70%, pressed membrane, 4) HA 40%/CS 60% membrane, 5) HA 50%/CS 50% membrane, 6) HA 50%/CS 50%, pressed membrane, or 7) a sham . surgery control. The amount of newly formed bone from the surface of the rat calvarial defects was measured using histomorphometry, following 2- or 8- week healing intervals. Results: Surgical implantation of the HA - CS membrane resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. The HA - CS membrane would be significantly more effective than the chitosan membrane in early bone formation. Conclusions: Concerning the advantages of biomaterials, the HA-CS membrane would be an effective biomaterial for regeneration of periodontal bone. Further studies will be required to improve the mechanical properties to develop a more rigid scaffold for the HA-CS membrane.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.461-468
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• 2009

Purpose: Platelet derived growth factor(PDGF)-BB and bone morphogenetic protein(BMP)-2 are well-known representative growth factors. The purposes of this study were to investigate the effect of rhPDGFBB and rhBMP-2 on osseointegration of titanium implants at periimplant bone defects grafted with hydroxyapatite and to evaluate the feasibility of imaging bone structures around screw-type titanium implant with micro-CT. Materials and Methods: The first molar and all premolars in the mandible region of four beagle dogs were extracted. Following a healing period of 4 months, three $8{\times}8{\times}6mm$-sized bony defects were formed and screw-type titanium implants were placed with hydroxyapatite(HA) block and growth factors; Control group, PDGF group and BMP group. Two months post-implantation, the mandible was harvested. Bone volume(BV), bone-to-implant contact(BIC) and bone mineral density(BMD) were analyzed with micro-CT and histology. Results: According to micro-CT analysis, BV and BMD measures of PDGF and BMP group were significantly higher than control group(BV; PDGF group: $p{\fallingdotseq}0.011$, BMP group: $p{\fallingdotseq}0.006$/BMD; PDGF group: $p{\fallingdotseq}0.020$, BMP group: $p{\fallingdotseq}0.011$) and BIC measures of BMP group were significantly higher than PDGF group($p{\fallingdotseq}0.015$). In histologic evaluation, BIC measures of BMP group was significantly higher than PDGF group($p{\fallingdotseq}0.048$). The values of BV in histologic sections were higher than in micro-CT images and the values of BIC in micro-CT images were higher than in histologic sections. Conclusion: The findings of this experimental study indicates that the use of rhPDGF-BB and rhBMP-2 can increase new bone formation in a large bony defect around titanium implant, and rhBMP-2 is more effective than rhPDGF-BB. Micro-CT can be considered useful for assessment as a rapid and nondestructive method for 3-dimensional measurement of bone healing around implants. Further study is necessary, however, to remove metal artifacts around titanium implant and to standardize the method.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.603-613
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• 1995

The purpose of this investigation was to evaluate on the biodegradability, biocompatibility and tissue regenerative capacity of synthetic bioabsorbable membranes in beagle dogs. For animal study, 9 adult beagle dogs were used to examination, on the surgical implantation of membranes and histological analysis. In each animal, the 3rd and 4th premolars of the both sides of the mandible were selected as test teeth. Two types of bioresorbable membranes including "Guidor membrane", "S-membranes" were used to examining for biological activity, and also Gore-tex membranes was used for positive control. Surgically created defects were made in 2 premolars of both sides of the mandible at $3{\times}4mm^2$ in size and tested membranes were implanted in the defected area. A plaque control regimen was instituted with daily tooth brushing with a 0.1% chlorhexidine digluconate during experimental periods. All the experimental animals were sacrificed after 2, 4, and 8 weeks from surgery and undecalcified slides were prepared using the "sawing and grinding" technique described by Donath and Breuner". In biodegradability, all the membranes were started their biodegradation from two weeks after implantation and gradually demolished of their frame morphology from eight weeks. However, demolition of membranes in 8 weeks after implantation was highest in Guidor membranes and followed by S-membranes. Biocompatibilityof two kinds of biodegradable membranes including Guidor and S-mambrane were shown to be well tolerated to the surrounding tissue, and were minimal accumulation of inflammatory cell infiltration around the implanted membranes to compare with Gore-tex membrane. Regeneration of defected alveolar bone was initiated from two weeks of membrane implantation and new bone formation was gradually increased from that time. However, pattern of new bone formation on the defected areas of two kinds of biodegrable membranes was almost similar and quite competitive comparing with Gore-tex membrane. These results implicate that bioresorbable membranes should be highly useful tool for guided tissue regeneration of periodontal defects.

• 동의신경정신과학회지
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• 제26권3호
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• pp.319-336
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• 2015

Objectives: The object of this study was to evaluate the cognition and motor function recovery effects of Sungshim-san (SSS), a traditional Korean cardio-protective polyherbal formula in the severe rat stroke, permanent middle cerebral artery occlusion (pMCAO) model. Methods: The experimental animals were divided into 6 groups. SSS aqueous extracts (yield=16.82%; 400, 200 and 100 mg/kg) were administered orally by using Sonde, once daily, for 28 continuous days from 24 hrs post-pMCAO. Donepezil 10 mg/kg, a representative drug for dementia, was used as a reference drug. The body weight changes, infarct/defect sizes, sensorimotor function and cognitive motor behavior were serially monitored. Limb placing and body-swing test for sensorimotor functions were conducted at 1 day before operation (base line), and 1, 3, 7, 14, 21 and 28 days post-pMCAO; and water maze test for the cognitive motor behavior was conducted at 14 and 28 days post-pMCAO, respectively. Results: Focal cerebral cortex infarct and defects due to pMCAO resulted in marked decreases of body weight, disorders of sensorimotor functions and cognitive motor behaviors. However, the pMCAO-related ischemic damages were markedly and dose-dependently inhibited by treatment with SSS 400 and 200 mg/kg, respectively. Donepezil markedly decreased the body weight and gains, as compared with pMCAO control rats; however, SSS 400 and 200 mg/kg favorably ameliorated the pMCAO-induced decreases in body weight and gains. SSS 100 mg/kg treated rats did not show any favorable effects on the pMCAO-related ischemic damages, as compared with pMCAO control rats. Conclusions: The results of the study indicated that oral administration of SSS 400 and 200 mg/kg accelerated cognition and motor function recovery in the rat pMCAO model. The treatment effect was potentially mediated by neuroprotection via the known augmentation of cerebral antioxidant defense system of SSS itself or its individual herbal components. Especially, the overall effects of SSS 200 mg/kg were similar to those of donepezil 10 mg/kg, but less toxic.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.372-379
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• 2009

Purpose: The purpose of this study was to compare the effect on antibacterial activities and wound healing effect of silver containing dressings with which of Betadine against Staphylococcus aureus and Pseudomonas aeruginosa. Methods: One full thickness skin defects in rats(n=72) were developed on the back and were given rise to infection with S. aureus(n=36) and P. aeruginosa(n=36). The 72 mice were divided into 6 groups : Acticoat$^{(R)}$, Aquacel$^{(R)}$-Ag, Medifoam silver$^{(R)}$, Polymen silver$^{(R)}$, Ilvadon$^{(R)}$ and Betadine(control group) dressing groups. Five silver containing dressings and Betadine were assesed on infected wound. Measurement of wound size change, bacterial colonies count and histologic findings was applied. Antibacterial activity was analyzed with bacterial restricted zone in Mueller Hinton agar. Results: On S. aureus, wound size was more decreased in all treated groups as compared with betadine, however Ilvadon$^{(R)}$ was less decreased on P. aeruginosa. In histologic findings, experimental group showed more effective findings than others on S. aureus, however on P. aeruginosa, which was showed similar. Acticoat$^{(R)}$ was best effective in wound healing against S. aureus and P. aeruginosa. The bacterial colonies count was increased in all treated groups except Acticoat$^{(R)}$ as compared with the control group on S. aureus, which was decreased in Acticoat$^{(R)}$ and Ilvadon$^{(R)}$ group on P. aeruginosa. There were not statistical differences. The restricted zone was shown in Mueller - Hinton agar of all groups except Medifoam silver$^{(R)}$ group on S. aureus, which was shown of all groups on P. aeruginosa. There were statistical differences. Conclusion: This study suggests that silver containing dressings may have not better potential than Betadine in assisting management of wounds at risk of infection on S. aureus and P. aeruginosa. However, which have better antibacterial activity on S. aureus and P. aeruginosa.

• 한국임상수의학회지
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• 제26권2호
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• pp.123-129
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• 2009

동맥관 개존증(PDA)은 동맥관의 불완전한 폐쇄로 인해 하행 대동맥과 폐동맥 사이에 비정상적인 단락이 형성된 것이다. 최근 인간의 유전자 연구에서 전사인자 AP-2 beta(TFAP2B)의 유전자 변이가 PDA 증후적 사례를 초래함을 발견하였다. TFAP2B 유전자의 변이는 사람의 PDA와 같은 특정 선천성 심장 기형과 관련되어 있다. 본 연구에서는 PDA에 이환된 개의 유전자 스크리닝을 하기 위해 개 TFAP2B유전자의 전체 exon 부위를 분리하였다. 개 TFAP2B유전자는 사람의 TFAP2B와 아미노산 서열이 매우 유사하였다. PDA에 이환된 말티즈견의 TFAP2B유전자 스크리닝에서 단일 c.936+203G>A 염기 변화가 발견되었다. 그러나 대조군의 유전자 스크리닝에서도 동일한 염기 변화가 발견되었다. 이 염기의 변화는 인트론 지역에 위치해 있었으며 이환되지 않은 대조군 개에서 발견된 것으로 보아 TFAP2B는 말티즈 견의 유전성 PDA와 다른 종의 PDA 환자를 초래하지 않을 것으로 보인다. 향후 더 많은 샘플을 모으고 PDA에 이환된 다양한 종과 다른 선천성 심장 기형을 가진 환축에서 TFAP2B를 스크리닝하는 연구가 필요하다.