• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.519-540
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• 1999

The purpose of this study is to compare the healing aspects of the use of ePTFE membrane alone versus combination treatment of ePTFE membrane and bone grafts on class II furcation defects. Seventeen defects were applied ePTFE membrane alone on mxillary molar buccal class II furcation defects as Group I, seventeen defects were applied ePTFE membrane and bone grafts on maxillary molar buccal class II furcation defects as Group II, twenty-three defects were applied ePTFE membrane alone on mandibular molar buccal class II furcation defects as Group III, twenty defects were applied ePTFE membrane and bone grafts on mandibular molar buccal class II furcation defects as Group IV . Measurements were made to determine clinical attachment level, probing depth, gingival depth, SBI, mobility at baseline, 3, 6, 12 months postoperatively. Additional measurements were made to determine membrane exposure level at surgery, 1, 2, 6 weeks postoperatively. And then healing patterns and postoperative complications were evaluated. The result as follows : There were statistically significant differences in probing depth reduction, clinical attachment gain, mobility reduction at values of 3, 6, 12 months postoperatively compared to values of baseline(p<0.05), whereas no significant differences in SBI and gingival recession. In group II, membrane exposure level was increased at 1, 2, 6 weeks postoperatively compared to value of baseline(p<0.05). There were statistically significant differences in changes of probing depth at 3, 6, 12 months postoperatively in combination groups of ePTFE membrane and bone graft compared to groups of ePTFE membrane alone(p<0.05). The vast majority of cases fall into typical healing and delayed healing response when membranes were removed in all groups. Pain and swelling were common postoperative complications. In conclusion, this study was showed more effective healing aspects in combination treatment of ePTFE membrane and bone graft than ePTFE membrane alone and on mandibular molar class II furcation defects than maxillary molar.

• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.553-560
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• 1999

The aim of the present study was to evaluate the effect of the expanded polytetrafluoroethylene (e-PTFE) membrane exposure on the initial healing of the periodontal tissue in guided tissue regeneration (GTR) procedure. 90 sites selected from 90 patients were treated with gingival flap surgery supported by an e-PTFE membrane. The material included angular bony defects with probing attachment loss of > 5mm or degree II furcation involvement. Treated sites were classified with membrane exposure group and non-exposure group at membrane removal and evaluated healing type. The results were obtained as follows. 1. e-PTFE membrane was exposed at 61 sites (67.8%) among 90 sites. 2. Thirteen sites (14.4%) depicted rapid healing type, 65 sites (72.2%) depicted typical healing type, 9 sites (10%) showed delayed healing type and 3 sites (3.3%) were categorized as adversed healing type. 3. In e-PTFE membrane exposure group, 1 site (1.6%), 51 sites (83.6%), 6 sites (9.8%) and 3 sites (4.9%) showed rapid healing type, typical healing type, delayed healing type and adverse healing type respectively. 4. In e-PTFE membrane non-exposure group, 12 sites (41.3%), 14 sites (48.3%) and 3 sites (10.3%) showed rapid healing type, typical healing type and delayed healing type respectively. Adverse healing type was not observed. 5. The rate of favourable healing between e-PTFE membrane exposure group and non-exposure group was not statistically significant(p=0.56). These results suggest that the prevention of membrane exposure may be important to obtain rapid healing type. However favourable healing could be obtained with stringent infection control program even if membrane was exposed.

• Journal of Periodontal and Implant Science
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• 제34권4호
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• pp.711-722
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• 2004

The purpose of this study is to evaluate the regenerated bone histollogically using titanium reinforced ePTFE(TR-ePTFE) membrane and to investigate cell occlusiveness, wound stabilization and tissue integration of TR-ePTFE membrane. Adult male rabbits (mean BW 2kg) and TR9W (W.L.Gore&Associate.INC,USA) were used in this study. Intramarrow penetration defects were surgically created with round carbide bur(HP long #6) on calvaria of rabbits. TR-ePTFE membrane was applied to defect. Then guided bone regeneration was carried out using TR-ePTFE membrane and resorbable suture. At 2,4,8,12 weeks after the surgery, animals were sacrificed. Nondecalcified specimens were processed for histologic analysis. The result and conclusion of this study were as follows: 1. TR-ePTFE membrane had good ability of biocompatibility and cell occlusiveness. 2. space making for guided bone regenerayion was good at TR-ePTFE membrane. 3. Tissue integration was not good at TR-ePTFE membrane. So, wound stabilization was not good. 4. At 8 weeks, 12 weeks after GBR procedure, bone formation was seen. From the above results, TR-ePTFE membrane fixed tightiy on alveolar bone might be recommended for the early bone formation.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.133-142
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• 1996

Ten intrabony defects in 10 patients were treated by flap surgery including root surface debridement and placement of an expanded polytetrafluoroethylene(ePTFE) membrane. The membranes were removed after 4-6 weeks. This study was performed to examine the retrived ePTFE membrane by scanning electron microscopy(SEM) for bacterial contamination and adherent connective tissue elements, and to compare it with clinical conditions. The cervical portion of the membrane, which in most cases had become partially exposed to the oral cavity, had a bacterial deposit. Small bacterial colonies and a scatter of single cells in some instances extended into the apical portion of the membrane. Fibroblast-like cells, erythrocytes and fibrous structures were seen in the apical portion of the membrane. Outer surface of membrane tends to more bacterial contamination than inner surface(p<0.01), and upper portions more than lower portions(P<0.01). Comparison of ultrastructural findings and clinical conditions revealed that extent of bacterial contamination of the membrane correlated with gingival inflammation and extent of membrane exposure, but it was not significant statistically. The results suggested that gingival inflammation and membrane exposure affect periodontal regeneration by the use of ePTFE membrane.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.47-67
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• 1996

The purpose of this study was to observe the effect of $Biocoral^R$ graft and bioglass 45S5 graft in combination with ePTFE membrane in periodontal osseous defects for new bone formation. Nine healthy dogs were used. Under general anesthesia, 3-wall defects were created on the mesial and distal surfaces of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars. To induce periodontitis, a silicone rubber, $Provil^R$ light body, was injected under pressure into the defects. Ninety days later, $Provil^R$was removed and followed by thorough root planing. The followings were then applied in the mesial and distal defects of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars by random selections : 1) ePTFE membrane only application, 2) $Biocoral^R$ graft, 3) $Biocoral^R$ graft and ePTFE membrane application, 4)Bioglass 45S5 graft, 5) Bioglass 45S5 graft and ePTFE membrane application. The membranes were removed 1 month later. The dogs were sacrified at 1, 2 and 3 months following the graft, and block sections were made, demineralized, embedded, stained and examined by light microscope and transmission electron microscope. On the sections from teeth treated with ePTFE membrane only, the defect demonstrated extensive connnective tissue and alveolar bone regeneration. The $Biocoral^R$ graft group demonstrated extensive bone regeneration compared with ePTFE membrane only group. In the $Biocoral^R$ graft plus ePTFE membrane group, regeneration of new alveolus and crest occurred within the defect. As the experimental period lengthened, bone regeneration was increased and bone bridge was formed among the graft particles. The but bioglass 45S5 graft group demonstrated extensive bone regeneration but the amount of new bone was less than that of the $Biocoral^R$ graft group. For the bioglass 45S5 graft plus ePTFE membrane group, the amount of new bone was also increased. As the experimental period lengthened, bone regeneration was increased. Multinucleated giant cells, fibroblasts and macrophages were observed. As the bone formation was increased, the number of such cells was decreased. In conclusion, the $Biocoral^R$ was found better than the bioglass 45S5 for new bone formation, and the use of ePTFE membrane alone or with $Biocoral^R$/bioglass 45S5 can be supported as potential methods of promoting bone formation.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.491-510
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• 2005

This study was performed to evaluate the effect of inorganic polyphosphate on bone formation in the calvaria of rabbit in the procedure of guided bone regeneration with bovine cancellous bone graft and titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group I used only TR-ePTFE membrane, control group II used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in saline, experimental group III and IV used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 1% or 2% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 12 rabbits with titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in saline or inorganic polyphosphate. The animals were sacrificed at 2 weeks, 4 weeks, and 8 weeks after the surgery. Decalcified and non-decalcified specimens were processed for histologic and immunohistochemistric analysis. 1. Titanium reinforced ePTFE(TR-ePTFE) membrane showed good spacemaking and cell occlusiveness capability, but it showed poor wound stabilization. 2. The deproteinized bovine bone mineral did not promote bone regeneration, but it acted as a space filler. 3. There was no complete resorption of the deproteinized bovine bone mineral within 8 weeks. 4. 1% inorganic polyphosphate did not promote bone formation, but 2% inorganic polyphosphate promoted bone formation. Within the above results, 2% inorganic polyphosphate could be used effectively for bone regeneration.

• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.325-334
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• 2008

Purpose: The carrier used as delivery agent for bone morphogenetic proteins(BMPs) should also act as a scaffold for new bone formation. Moreover, bone formation should be predictable in terms of the volume and shape. This study examined the osteogenic effect of macroporous biphasic calcium phosphate (MBCP) block combined with ePTFE membrane as a carrier for recombinant human bone morphogenetic proteins (rhBMP-2). In addition, the additive effect of ePTFE membrane on bone formation was evaluated. Materials and Methods: Eight-millimeter critical sized calvarial defects were created surgically in 28 male Sprague-Dawley rats. The animals were divided into 2 groups containing 14 animals each. The defects were treated with either rhBMP-2/MBCP block (rhBMP-2/MBCP group) or rhBMP-2/MBCP block/ePTFE membrane (rhBMP-2/MBCP/ePTFE group). A disc-shaped MBCP block (3 mm height and 8 mm diameter) was used as the carrier for the rhBMP-2 and ePTFE membrane was used to cover the rhBMP-2/MBCP block. The histologic and histometric parameters were used to evaluate the defects after 2- or 8-week healing period (7 animals/group/healing interval). Results: The level of bone formation in the defects of both groups was significantly higher at 8 weeks than that at 2 weeks (P < 0.05). The ePTFE membrane has no additional effect compared with the rhBMP-2/MBCP block only. However, at 8 weeks, rhBMP-2/MBCP/ePTFE group showed more even bone formation on the top of the MBCP block than the rhBMP-2/MBCP group. Conclusion: These results suggest that the ePTFE membrane has no additive effect on bone formation when a MBCP block is used as a carrier for rhBMP-2.

• Korean Chemical Engineering Research
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• 제58권4호
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• pp.536-540
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• 2020

고분자연료전지(PEMFC) 고분자막의 지지체는 기계적 내구성 향상에 핵심적인 역할을 한다. 지지체로 사용하는 e-PTFE는 화학적으로 안정하여 PEMFC 구동과정에서 전기화학적인 열화에 대해서는 거의 연구되지 않았다. 본 연구에서는 e-PTFE가 Fenton 반응과정에서 발생한 라디칼과 과산화수소에 화학적으로 안정한지 검토하였다. Fenton 반응 과정에서 e-PTFE의 주사슬이 끊어져 지지체의 화학적 구조와 형태 변화가 발생하였고, 그에 따라 인장 강도가 감소하였다. 실제 PEMFC 구동과정에서 고분자막 이오노머의 전기화학적 열화는 라디칼과 과산화수소에 의해서 고분자막 내부에서 발생하므로, e-PTFE 지지체의 셀 내에서 전기화학적 열화도 발생할 수 있음을 본 연구 결과가 보였다.

• 멤브레인
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• 제33권4호
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• pp.201-210
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• 2023

먼지 필터 막은 인간의 건강, 안전 및 환경 보호의 몇 가지 중요한 측면에 기여하기 때문에 인간의 삶과 다양한 산업에서 중요한 역할을 한다. 이 연구는 고온 조건에 대한 우수한 열안정성과 접착 특성을 가진 polysulfone@polyphenylene sulfide/polytetrafluoroethylene (PSf@PPS/ePTFE) 복합 먼지 필터 막의 개발을 제시한다. FT-IR 분석은 PSF 접착제가 PPS 직물에 성공적으로 함침되고 ePTFE 지지체와의 상호 작용을 확인한다. FE-SEM 이미지는 향상된 섬유 상호 연결 및 PSf 농도와 함께 접착력을 보여준다. PSf@PPS/ePTFE-5는 가장 적합한 다공성 구조를 보여준다. 복합 막은 400℃까지 예외적인 열 안정성을 보여준다. 박리 저항 테스트는 먼지 여과에 대한 충분한 접착력을 보여 공기 투과성을 희생시키지 않고 힘든 고온조건에서 신뢰할 수 있는 성능을 보장한다. 이 막은 산업 응용 분야에서 유망한 잠재력을 제공한다. 더 나아가 최적화 및 응용 가능성을 탐구할 수 있다.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.103-116
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• 1996

This study was performed to observe the bacterial adhesion and penetration to e-PTFE membrane following guided tissue regeneration(GTR) procedure and to evaluate the association of the membrane exposure and bacterial contamination with the clinical outcome. For the study, ten infrabony defects in 9 patient were treated by mucoperiosteal flap operation including placement of the e-PTFE membrane. The treated teeth were monitored weekly for the membrane exposure, gingival recession and gingival inflammation. The membranes were retrieved after 4 to 6 weeks, examined by SEM for bacterial contamination and adherent connective tisue elements, and observed under LM for the bacterial penetration into membrane. Three months postsurgery, the defect sites were clinically reexamined for the changes in attachment level and probing depth. Comparison of the ultrastuctural findings and clinical outcome revealed that extent of membrane exposure and bacterial contamination of the membrane was inversely associated with clinical attachment gain. From this finding, the extent of membrane exposure and the bacterial contamination on the apical portion of the e-PTFE membrane at the time of removal seemed to be a critical determinant on the clinical outcome of GTR and the membrane exposure needs to be controlled for optimal results.