• Journal of Periodontal and Implant Science
• /
• 제23권3호
• /
• pp.577-594
• /
• 1993

Polytetrafluoroethylene membrane 및 millipore filter를 섬유소와 병용사용하여 성견 치주조직 재생에 미치는 영향에 관해 알아보기 위하여 생후 9개월 이상된 잡종성견7마리에 치은박리소파수술후 PTFE membrane를 삽입한 군을 대조군으로, PTFE membrane에 섬유소를 첨가했는 군을 실험1군으로, 수술시 millipore filter를 봉합에 의해 고정시킨군을 실험2군으로, 섬유소로 millipore filter를 고정시킨 군을 실험3군으로 하였다. 술후 각 1, 2, 4, 8, 12 주에 관류고정과 아울러 희생시켜 악골을 채취하고 통법에 의해 후고정, 탈회, 탈수과정을 거쳐 파라핀으로 포매한 후 $4-6{\mu}m$두께의 협, 설측 박편을 제작한 후 H & E 및 Masson’s trichrome염색 후 광학현미경으로 치유결과를 조직학적으로 비교 관찰하여 다음과 같은 결과를 얻었다. 1 주때 대조군 및 실험각군 모두 치은상피조직의 근단이동이 억제된 양상을 나타내었으며, millipore filter를 삽입한 군에서는 섬유소보다 봉합에 의해 막을 고정시킨 경우 술후 1주때 부터 치은퇴축으로 인한 막의 노출이 관찰되었고 술후 4주때 막의 내, 외면에 긴접합상피조직의 근단이동을 관찰할 수 있었으며, PTFE membrane 경우는 섬유소유무에 따른 차이는 관찰되지 않았다. 대조군 및 실험각군 모두 술후 1주때 골양조직을 관찰할 수 있었고 4주때 성숙된 치조골 양상을 보였으며 특히 PTFE membrane인 경우 증가된 협설 측 폭경을 관찰할 수 있었으며, 술후 12주때 실험각군 모두 치조골이 더욱 성숙된 양상을 관찰할 수 있었다. 술후 4주때 대조군, 실험각군 모두 활택된 치근면상에 미약한 신생백악질 및 불규칙적인 교원섬유의 배열을 관찰할 수 있었고 8주때 뚜렷한 백악질의 증가와 12주때에는 신생백악질과 신생치조골 사이에 기능적으로 배열된 교원 섬유를 관찰할 수 있었다. 결론적으로, 섬유소로 막을 고정시킬 경우 치근면과의 긴밀한 접촉을 유지시킬수 있으며, 차단막을 근단쪽으로 위치시켜 막의 노출 위험을 감소시킬수 있으며, 특히 PTFE membrane인 경우 봉합대체물로의 연이은 연구가 필요할 것으로 사료된다.

• Journal of Periodontal and Implant Science
• /
• 제29권3호
• /
• pp.483-509
• /
• 1999

Biodegradable barrier membrane has been demonstrated to have guided bone regeneration capacity on the animal study. The purpose of this study is to evaluate the effects of cultured calvarial cell inoculated on the biodegradable barrier membrane for the regeneration of the artificial bone defect. In this experiment 35 Sprague-Dawley male rats(mean BW 150gm) were used. 30 rats were divided into 3 groups. In group I, defects were covered periosteum without membrane. In group II, defects were repaired using biodegradable barrier membrane. In group III, the defects were repaired using biodegradable barrier membrane seeded with cultured calvarial cell. Every surgical procedure were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). After anesthesia, 5 rats were sacrificed by decapitation to obtain the calvaria for bone cell culture. Calvarial cells were cultured with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. The number of cell inoculated on the membrane were $1{\times}10^6$ Cells/ml. The membrane were inserted on the artificial bone defect after 3 days of culture. A single 3-mm diameter full-thickness artificial calvarial defect was made in each animal by using with bone trephine drill. After the every surgical intervention of animal, all of the animals were sacrificed at 1, 2, 3 weeks after surgery by using of perfusion technique. For obtaining histological section, tissues were fixed in 2.5% Glutaraldehyde (0.1M cacodylate buffer, pH 7.2) and Karnovsky's fixative solution, and decalcified with 0.1M disodium ethylene diaminetetraacetate for 3 weeks. Tissue embeding was performed in paraffin and cut parallel to the surface of calvaria. Section in 7${\mu}m$ thickness of tissue was done and stained with Hematoxylin-Eosin. All the specimens were observed under the light microscopy. The following results were obtained. 1 . During the whole period of experiment, fibrous connective tissue was revealed at 1week after surgery which meant rapid soft tissue recovery. The healing rate of defected area into new bone formation of the test group was observed more rapid tendency than other two groups. 2 . The sequence of healing rate of bone defected area was as follows ； test group, positive control, negative control group. 3 . During the experiment, an osteoclastic cell around preexisted bone was not found. New bone formation was originated from the periphery of the remaing bone wall, and gradually extended into central portion of the bone defect. 4 . The biodegradable barrier membrane was observed favorable biocompatibility during this experimental period without any other noticeable foreign body reaction. And mineralization in the newly formed osteoid tissue revealed relatively more rapid than other group since early stage of the healing process. Conclusively, the cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of regeneration of artificial bone defects of alveolar bone. This study thus demonstrates a tissue-engineering the approach to the repair of bone defects, which may have clinical applications in clinical fields of the dentistry including periodontics.

• Journal of Periodontal and Implant Science
• /
• 제31권1호
• /
• pp.1-23
• /
• 2001

Chitosan is biodegradable natural polymer that has been demonstrated its ability to improve wound healing, and calcium metaphosphate(CMP) is a unique class of phosphate minerals having a polymeric structure. In this study, chitosan/CMP and platelet derived growth factor(PDGF-BB) loaded chitosan/CMP sponges were developed, and the effect of the sponges on bone regeneration and their possibility as scaffolds for bone formation by three-dimensional osteoblast culture were examined. PDGF-BB loaded chitosan/CMP sponges were prepared by freeze-drying of a mixture of chitosan solution and CMP powder, and soaking in a PDGF-BB solution. Fabricated sponge retained its 3-dimensional porous structure with $100-200\;{\mu}m$ pores. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with $^{125}I-labeled$ PDGF-BB. In order to examine their possibility as scaffolds for bone formation, fetal rat calvarial osteoblastic cells were isolated, cultured, and seeded into the sponges. The cell-sponge constructs were cultured for 28 days. Cell proliferation, alkaline phosphatase activity were measured at 1, 7, 14 and 28 days, and histologic examination was performed. In order to examine the effect on the healing of bone defect, the sponges were implanted into rat calvarial defects. Rats were sacrificed 2 and 4 weeks after implantation and histologic and histomorphometrical examination were performed. An effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. PDGF-BB loaded chitosan/CMP sponges supported the proliferation of seeded osteoblastic cells as well as their differentiation as indicated by high alkaline phosphatase activities. Histologic findings indicated that seeded osteoblastic cells well attached to sponge matrices and proliferated in a multi-layer fashion. In the experiments of implantation in rat calvarial defects, histologic and histomorphometric examination revealed that chitosan/CMP sponge promoted osseous healing as compared to controls. PDGF-BB loaded chitosan/CMP sponge further echanced bone regeneration. These results suggested that PDGF-BB loaded chitosan/CMP sponge was a feasable scaffolding material to grow osteoblast in a three-dimentional structure for transplantation into a site for bone regeneration.

• 대한치과교정학회지
• /
• 제27권6호
• /
• pp.955-961
• /
• 1997

흡연의 주성분중의 하나인 니코틴은 인체내에 다양한 전신적 및 국소적인 질환의 원인으로 보고 되어지고 있다. 전신적인 질환에 있어 특히, 호흡기와 순환기 조직세포에 대한 세포분열효과가 많은 연구의 초점이 되어왔으며, 국소적인 효과에 대한 연구에서는 조직파괴나 치료후 치유지연에 대해 보고하고 있다. Platelet-Derived Growth Factor(PDGF)와 Insulin-like Growth Factor(IGF)는 치주인대세포의 세포분열을 촉진하는 주요 성장인자로 알려져있다. 본 연구의 목적은 니코틴이 사람의 치주인대세포에 미치는 세포분열효과를 알아보기 위하여 니코틴 처리된 치주인대세포로부터 추출한 PDGF-${\alpha}\;and\;{\beta}$ receptor 및 IGF-l 수용기의 mRNA변화를 Northern분석을 이용해 확인해 보고자 함이다. 실험군은 각기 다른 농도의 니코틴(100ng/ml, 1000mg/ml)과 배양액내 혈청농도($1\%,\;10\%$)로 나누었으며 이를 각각 니코틴 처리 시간에 따라 분류하였다. 본연구의 결과로 $10\%$ 혈청의 배양액과 100ng/ml 니코틴 농도군에서 모든 성장인자 수용체의 mRNA가 증가됨을 보였으며 이는 흡연자의 체내 축적 가능한 니코틴 농도에서 치주인대세포의 세포분열을 촉진한다는 추측을 가능케 한다.

• Journal of Periodontal and Implant Science
• /
• 제46권4호
• /
• pp.220-233
• /
• 2016

Purpose: The aim of this study was to present new a model that allows the study of the bone healing process, with an emphasis on the biological behavior of different graft-to-host interfaces. A standardized "over-inlay" surgical technique combined with a differential histomorphometric analysis is presented in order to optimize the use of critical-size calvarial defects in pre-clinical testing. Methods: Critical-size defects were created into the parietal bone of 8 male Wistar rats. Deproteinized bovine bone (DBBM) blocks were inserted into the defects, so that part of the block was included within the calvarial thickness and part exceeded the calvarial height (an "over-inlay" graft). All animals were sacrificed at 1 or 3 months. Histomorphometric and immunohistochemical evaluation was carried out within distinct regions of interest (ROIs): the areas adjacent to the native bone (BA), the periosteal area (PA) and the central area (CA). Results: The animals healed without complications. Differential morphometry allowed the examination of the tissue composition within distinct regions: the BA presented consistent amounts of new bone formation (NB), which increased over time ($24.53%{\pm}1.26%$ at 1 month; $37.73%{\pm}0.39%$ at 3 months), thus suggesting that this area makes a substantial contribution toward NB. The PA was mainly composed of fibrous tissue ($71.16%{\pm}8.06%$ and $78.30%{\pm}2.67%$, respectively), while the CA showed high amounts of DBBM at both time points ($78.30%{\pm}2.67%$ and $74.68%{\pm}1.07%$, respectively), demonstrating a slow remodeling process. Blood vessels revealed a progressive migration from the interface with native bone toward the central area of the graft. Osterix-positive cells observed at 1 month within the PA suggested that the periosteum was a source of osteoprogenitor elements. Alkaline phosphatase data on matrix deposition confirmed this observation. Conclusions: The present model allowed for a standardized investigation of distinct graft-to-host interfaces both at vertically augmented and inlay-augmented sites, thus possibly limiting the number of animals required for pre-clinical investigations.

• Journal of Periodontal and Implant Science
• /
• 제46권3호
• /
• pp.176-196
• /
• 2016

Purpose: We sought to evaluate the effectiveness of bone substitutes in circumferential periimplant defects created in the rabbit tibia. Methods: Thirty rabbits received 45 implants in their left and right tibia. A circumferential bone defect (6.1 mm in diameter/4 mm depth) was created in each rabbit tibia using a trephine bur. A dental implant ($4.1mm{\times}8.5mm$) was installed after the creation of the defect, providing a 2-mm gap. The bone defect gaps between the implant and the bone were randomly filled according to the following groups: blood clot (CO), particulate Bio-Oss$^{(R)}$ (BI), and Bio-Oss$^{(R)}$ Collagen (BC). Ten animals were euthanized after periods of 15, 30, and 60 days. Biomechanical analysis by means of the removal torque of the implants, as well as histologic and immunohistochemical analyses for protein expression of osteocalcin (OC), Runx2, OPG, RANKL, and TRAP were evaluated. Results: For biomechanics, BC showed a better biological response ($61.00{\pm}15.28Ncm$) than CO ($31.60{\pm}14.38Ncm$) at 30 days. Immunohistochemical analysis showed significantly different OC expression in CO and BC at 15 days, and also between the CO and BI groups, and between the CO and BC groups at 60 days. After 15 days, Runx2 expression was significantly different in the BI group compared to the CO and BC groups. RANKL expression was significantly different in the BI and CO groups and between the BI and BC groups at 15 days, and also between the BI and CO groups at 60 days. OPG expression was significantly higher at 60 days postoperatively in the BI group than the CO group. Conclusions: Collectively, our data indicate that, compared to CO and BI, BC offered better bone healing, which was characterized by greater RUNX2, OC, and OPG immunolabeling, and required greater reversal torque for implant removal. Indeed, along with BI, BC presents promising biomechanical and biological properties supporting its possible use in osteoconductive grafts for filling peri-implant gaps.

• Journal of Periodontal and Implant Science
• /
• 제42권4호
• /
• pp.119-126
• /
• 2012

Purpose: The aim of this study was to determine whether biphasic calcium phosphate (BCP) bone substitute with two different concentrations of Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) enhances new bone formation in a standardized rabbit sinus model and to evaluate the concentration-dependent effect of ErhBMP-2. Methods: Standardized, 6-mm diameter defects were made bilaterally on the maxillary sinus of 20 male New Zealand white rabbits. Following removal of the circular bony windows and reflection of the sinus membrane, BCP bone substitute without coating (control group) was applied into one defect and BCP bone substitute coated with ErhBMP-2 (experimental group) was applied into the other defect for each rabbit. The experimental group was divided into 2 subgroups according to the concentration of ErhBMP-2 (0.05 and 0.5 mg/mL). The animals were allowed to heal for either 4 or 8 weeks and sections of the augmented sinus and surrounding bone were analyzed by microcomputed tomography and histologically. Results: Histologic analysis revealed signs of new bone formation in both the control and experimental groups with a statistically significant increase in bone formation in experimental group 1 (0.05 mg/mL ErhBMP-2 coating) after a 4-week healing period. However, no statistically significant difference was found between experimental group 1 and experimental group 2 (0.5 mg/mL ErhBMP-2 coating) in osteoinductive potential (P<0.05). Conclusions: ErhBMP-2 administered using a BCP matrix significantly enhanced osteoinductive potential in a standardized rabbit sinus model. A concentration-dependent response was not found in the present study.

• Journal of Periodontal and Implant Science
• /
• 제33권1호
• /
• pp.91-102
• /
• 2003

Several effective treatment methods and materials have been developed for the treatment of furcation involvement. Currently, the combination of guided tissue regeneration (GTR) and bone grafts is the most commonly prescribed method of treating furcation involved defects. But because these cases often present with poor accessibility, placement of the membrane may be difficult and consequently, clinically impractical. In this study, the alveolar bone healing patterns of adult beagle dogs presenting with alveolar bone destruction treated by one of two methods - treatment using solely bone allografts (BBP(R)), or treatment using bone allografts (BBP(R)) stabilized by a fibrin adhesive - were comp ared. The effects of the fibrin adhesive on the initial stabilization of the newly formed bone, subsequent regeneration of bone, and the feasibility of the clinical application of the fibrin adhesive were analyzed. The results of the study were as follows: 1. Clinical signs of inflammation at the 4-8 week interval were not observed: but signs of mild inflammation were histologically observed at the 4-week interval. 2. Allografts stabilized by fibrin adhesive showed good bone formation, whereas defects treated with only the allograft material showed incomplete alveolar bone regeneration. 3. Allografts stabilized by fibrin adhesive showed a decrease in the amount old bone with a concurrent increase in the formation of new lamellar bone four weeks post-op, whereas defects treated with only the allograft material showed no new lamellar bone formation at the same interval. 4. In detects treated with only the allograft material, the defective area was filled with connective tissue 8-weeks post-op, whereas fibrin adhesive stabilized allografts showed viable connections between the original bone and the newly formed bone, in addition to neovascularization 8-weeks post-op. The results of this study show that concurrent use of fibrin adhesive materials can stabilize the allograft material and aid in new bone formation Although the stability of fibrin adhesives fall short of the results achievable by GTR membranes, in cases presenting with poor accessibility that contraindicate the use of membranes, fibrin adhesive materials provide a viable and effective alternative to graft stabilization and new bone formation.

• 구강회복응용과학지
• /
• 제25권3호
• /
• pp.279-285
• /
• 2009

본 연구의 목적은 인산칼슘제제인 $MBCP^{(R)}$, $Polybone^{(R)}$을 발치와에 이식 후 치유 양상을 조직학적으로 관찰하는 것이다. 비글견의 소구치를 발치 후 발치와에 골이식재를 이식하였으며, 3개월간의 치유기간을 거친 후 조직표본을 제작하여 현미경으로 치유 양상을 관찰하였다. $MBCP^{(R)}$, $Polybone^{(R)}$은 조직학적으로 비슷한 치유 양상을 보였으며 이물반응이나 염증 반응 없이 신생골 생성을 유도하여 정상적인 치유를 도모하였다. 치유된 조직의 조직 계측학적 평가에서 신생골 비율은 골이식재를 이식하지 않은 대조군이 34.5%, $MBCP^{(R)}$는 28.4%, $Polybone^{(R)}$은 23.8%였으며, 골이식재를 포함한 전체 mineralized tissue의 비율은 각각 34.5%, 42.9%, 37.3% 였다. 이상의 결과에서 $MBCP^{(R)}$, $Polybone^{(R)}$은 발치와에 사용할 골이식재로 가치가 있는 것으로 생각된다.

• Journal of Periodontal and Implant Science
• /
• 제26권4호
• /
• pp.873-887
• /
• 1996

Platelet-derived growth factor(PDGF) is one of the polypeptide growth fators. PDGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. Recent studies indicated that demineralized root surface as the primary site for growth factor application has advantages over other application method, especially due to binding capacity of growth factor for exposed matrix component of deminera1ized dentin surface. The purpose of this study is to evaluate optimal application time of PDGF-BB on proliferation of human gingival fibroblasts using deminera1ized dentin surface as primary application site. Human gingival fibroblasts and dentin slabs were prepared from the first premolar tooth extracted for the orthodontic treatment, cells were cultured in DMEM/I0% FBS at the $37^{\circ}C$, 5% CO2 incubator. All of the dentin slabs were preconditioned with Tetracycline HCI(100mg/ml) solution and rinsed in PBS. In the cell proliferation experiment, experimental group was immersed in DMEM containing 10% FBS, 50ng/rnl PDGF-BB during different time(30sec, 1, 2, 4, 8 minutes) and dried. Cells at concentration of $1{\times}10^5$cells/ml were seeded in each culture well which contained dentin slabs and incubated for 6 hours. Then, all of the dentin slabs were moved into new 24 well culture dish and incubated for 24, 48, 72 hours. The cell counting was done by hemocytometer with inverted phase contrast microscope after trypsinization. The results were as follows : The application of PDGF-BB for 1, 2 min slightly increased the number of gingival fibroblasts, and the application of PDGF-BB for 4, 8 min prominently increased the number of gingival fibroblasts. The application of PDGF-BB for 4 min showed maximum proliferation rate of gingival fibroblasts at 24, 48, 72 hours, and the application of PDGF-BB for 8 min showed less proliferation rate of gingival fibroblasts compared to the application of PDGF-BB for 4 min at 24, 48, 72 hours. In conclusion, the application of PDGF-BB for 4 min appeared to be optimal to obtain maximum proliferation of gingival fibroblasts using demineralized dentin surface as primary applicaton site of PDGF-BB.