d-PTFE Membrane Research Articles

Fabrication and characterization of a semi-rigid shell barrier system made of polycaprolactone and biphasic calcium phosphate: A novel barrier system for bone regeneration

Nowadays, no barrier membrane serves all purposes of bone augmentation. This study aimed to fabricate a semi-rigid shell barrier system composed of a semi-rigid shell and a covering membrane or a semi-resorbable barrier membrane, based on polycaprolactone (PCL) and biphasic calcium phosphate (BCP) for guided bone regeneration (GBR). A shell and a covering membrane were fabricated by a solvent casting technique based on PCL (70) and BCP (30). The experimental groups were a semi-rigid shell, an airdried membrane, a buffered membrane, and a commercial d-PTFE as a control. Physico-chemical, mechanical properties, and in vitro biocompatibility with osteoblasts and fibroblasts cells were evaluated in all groups. The fabricated materials had rough surfaces with a homogeneous distribution of BCP particles on one side and a smooth surface on the opposite side. The airdried membrane presented a rougher surface on both top and bottom sides (Sq=605.45nm, 556.82nm) than the semi-rigid shell (310.74nm, 424.56nm) and the buffered membrane (277.9nm, 306.98nm), respectively. The pore sizes of the airdried membrane (25-40μm) were larger than the semi-rigid shell (5-40μm) and the buffered membrane (5-25μm). The porosities of the airdried and buffered membranes (∼40%) were higher than the semi-rigid shell (∼20%) significantly (p<0.05). All fabricated materials were hydrophilic, with the lowest water contact angle in the semi-rigid shell (54.7°±3.06°), then the airdried (61.15°±4.76°), and the buffered (75.74°±2.8°) respectively. The semi-rigid shell resisted a higher load on compressive force (18.82±2.72N) than the d-PTFE membrane (4.23±0.5N). The tensile stress of the buffered membrane (2.544±0.19MPa) was not different from the d-PTFE (2.908±0.12MPa) but was higher than the airdried membrane (1.302±0.13MPa) significantly (P<0.05). The airdried membrane had reached 100% swelling ability within 1h, which was significantly faster than the buffered membrane (12h) and the semi-rigid shell (7 days), and they were slowly degraded by lysozyme at 6 months (airdried: 24.88%±0.96%, buffered: 13.67%±0.55%, and semi-rigid: 8.62%±0.88%). All fabricated membranes showed no toxicity to osteoblast and fibroblast cells. The semi-rigid shell and the covering membranes demonstrated suitable physical and mechanical properties, and biocompatibility, and can be assembled as the novel semi-rigid shell barrier system for bone regeneration.

EPTFE reinforced, sulfonated aromatic polymer membranes enable durable, high-temperature operable PEMFCs

SummarySulfonated polyphenylene (SPP)-based ionomers have been developed for electrochemical applications in recent years due to their inherent thermal and chemical stability. However, the difficult synthesis, limited solubility, and rigid backbone obstructs their progress. Herein, a new monomer, 3,3″-dichloro-2′,3′,5′,6′-tetrafluoro-1,1':4′,1″-terphenyl (TP-f) with high polymerization reactivity was designed and polymerized with sulfonated phenylene monomer to prepare SPP-based ionomers (SPP-TP-f) with high ion exchange capacity up to 4.5 mequiv g−1. The resulting flexible membranes were more proton conductive than Nafion (state-of-the-art proton exchange membrane) even at 120°C and 20% RH. Unlike typical SPP ionomers, SPP-TP-f 5.1 was soluble in ethanol and thus, could be reinforced with double expanded polytetrafluorethylene thin layers to obtain SPP-TP-f 5.1/DPTFE membrane. SPP-TP-f 5.1/DPTFE showed superior fuel cell performance to that of Nafion, in particular, at low humidity (30% RH, > 100°C) and reasonable durability under the severe accelerated conditions combining OCV hold and humidity cycling tests.

Evaluation of healing at molar extraction sites with ridge preservation using a non-resorbable dense polytetrafluoroethylene membrane: A four-arm cohort prospective study.

ObjectivesTo examine ridge dimensional changes and histologic parameters of healing when ridge preservation (RP) was performed at molar sites using dense polytetrafluoroethylene (dPTFE) membrane alone, without a bone graft.Material and MethodsEighteen patients had molar extraction and RP using dPTFE membrane alone. Ridge dimensions were measured using two standardized cone beam computerized tomography (CBCT) scans taken within 72 h and 3 months following extraction. Following a 3‐month healing period, an implant osteotomy was prepared using a trephine drill and bone cores were collected for histological analysis. Four‐arm analyses were performed using data from three previously published study arms of the same research group.ResultsThere was a significant change in the buccal ridge height between the four groups at all aspects of the socket. Alveolar ridge width reduction at 3 mm from crest for all aspects (mesial, midpoint, distal) of the socket showed statistically significant difference for dPTFE alone group compared to the other three groups. Percentage of vital bone formation (62.10%) was significantly greater in dPTFE alone group compared to the other groups.ConclusionsRP using dPTFE membrane alone in molar sites with intact socket walls showed successful outcomes in maintaining ridge dimensions and in histologic wound healing.

EPTFE Reinforced, Sulfonated Aromatic Polymer Membranes Enable Durable, High-Temperature Operable PEMFCs

Sulfonated polyphenylene (SPP)-based ionomers have been developed for electrochemical applications in recent years due to their inherent thermal and chemical stability. However, the difficult synthesis, limited solubility and rigid backbone obstructs their progress. Herein, a new monomer, 3,3''-dichloro-2',3',5',6'-tetrafluoro-1,1':4',1''-terphenyl (TP-f) with high polymerization reactivity was designed and polymerized with sulfonated phenylene monomer to prepare SPP-based ionomers (SPP-TP-f) with high ion exchange capacity up to 4.5 mequiv g-1. The resulting flexible membranes were more proton conductive than Nafion (state-of-the-art proton exchange membrane) even at 120 °C and 20% RH. Unlike typical SPP ionomers, SPP-TP-f 5.1 was soluble in ethanol and thus, could be reinforced with double ePTFE thin layers to obtain SPP-TP-f 5.1/DPTFE membrane. SPP-TP-f 5.1/DPTFE showed superior fuel cell performance to that of Nafion, in particular, at low humidity (30% RH, > 100 oC) and reasonable durability under the severe accelerated conditions combining OCV hold and humidity cycling tests.

Evaluation of a Minimally Invasive Alveolar Ridge Reconstruction Approach in Postextraction Dehiscence Defects: A Case Series.

This study evaluated a panel of clinical, dimensional, volumetric, implant-related, histomorphometric, and patient-reported outcome measures (PROMs) following reconstruction of dehiscence defects in extraction sockets with a minimally invasive technique using particulate bone allograft and a nonresorbable dense polytetrafluoroethylene (dPTFE) membrane. Subjects (n = 17) presenting severe buccal dehiscence defects at the time of single-rooted tooth extraction participated in the study. The mean vertical dimension of the dehiscence defects at baseline was 5.76 ± 4.23 mm. Subjects were followed up at 1, 2, 5, and 20 weeks postoperatively. The dPTFE barrier was gently removed at 5 weeks. CBCT and intraoral scans were obtained at baseline and at 20 weeks. A bone core biopsy sample was harvested at 24 weeks (before implant placement). Linear radiographic measurements revealed a mean increase in buccal bone height from baseline to 20 weeks (5.66 ± 5.1 mm; P < .0001). A total alveolar bone volume gain of 9.12% was observed. Although approximately half of the sites required some degree of additional bone augmentation at the time of implant placement, all implants were placed in a favorable restorative position with adequate primary stability. Histomorphometric analyses revealed a mean mineralized tissue area of 31.04% ± 15.22%, and the proportions of remaining allograft material and nonmineralized tissue were 16.23% ± 10.63% and 52.71% ± 9.53%, respectively. All implants survived up to 12 months after placement. PROMs were compatible with minimal discomfort at different postoperative stages and a high level of overall satisfaction upon study completion. This study demonstrated that the reconstructive procedure employed was successful and predictable in treating large, postextraction alveolar ridge deformities to optimize tooth replacement therapy with implant-supported prostheses.

Evaluation of the effectiveness of xenogenic material at the site of the osteoplastic procedure on the alveolar ridge of the jaw in case of exposure of the dPTFE membrane

Various types of techniques increase the volume of the atrophied alveolar ridge are used as bone blocks, ridge splitting, osteoperiostal flap, etc. However, one of the most promising methods to date is the GBR method. The use of bone-substituting materials and isolating membranes gives a reliable and predictable result in dental implantology. Recent studies using the dPTFE (dense polytetrafluoroethylene ) membrane have shown a positive result at the site of regeneration even if the membrane itself is exposed in repaired period. With this type of complication the membrane is removed at a period of 4–6 weeks and replaced with a collagen membrane with subsequent approximation of the edges of the flap by sutures (24, 25). This article shows the possibility of regenerating the bone graft from sole xenogenic material using dPTFE membrane in case wound dehiscence in repaired period but without using the collagen membrane coating step after removing dPTFE and it healing by secondary tension.

DIODE LASER PHOTOCOAGUALTION AS A NOVEL METHOD FOR SOCKET SEALING DURING ALVEOLAR SOCKET PRESERVATION

Introduction: Socket preservation is a procedure after tooth extraction to limit the post-extraction reduction of the ridge volume. Non-contact laser photocoagulation is a simple and atraumatic method used for socket sealing. Objectives: Compare the effect of diode laser photocoagulation to the non-resorbable dense polytetraflouoroethylene (dPTFE) membrane on the bone dimensional changes. Materials and methods: Thirty-six patients (n =18 for each group) with non-restorable maxillary anterior or premolar teeth were included in this study. After extraction, sites were grafted with deproteinized bovine bone xenograft and sealed either with laser photocoagulation or a non-resorbable dPTFE membrane. Measurements of the alveolar bone width were performed on cone beam computed tomographs, taken at the baseline before extraction and after 4 months. Results: Both groups showed a reduction in bone width. At the crest, the mean amount of reduction was 0.69 (0.33) mm and 0.78 (0.15) mm for the laser and membrane groups, respectively. As for the middle third, less amount of reduction was observed by a mean of 0.56 (0.36) mm and 0.58 (0.18) mm for the laser and membrane groups, respectively. The least amount of reduction was in the apical third with a mean of 0.26 (0.36) mm and 0.41 (0.17) mm for the laser and membrane groups, respectively. However, this reduction in bone dimensions was insignificant between both groups. Conclusion: The laser photocoagulation is as effective as the dPTFE membrane in sealing sockets after grafting.

Early plaque formation on PTFE membranes with expanded or dense surface structures applied in the oral cavity of human volunteers.

ObjectivesThis clinical randomized study aimed to evaluate the early plaque formation on nonresorbable polytetrafluoroethylene (PTFE) membranes having either a dense (d‐PTFE) or an expanded (e‐PTFE) microstructure and exposed to the oral cavity.Material and MethodsTwelve individuals were enrolled in this study. In a split‐mouth design, five test membranes (e‐PTFE) with a dual‐layer configuration and five control membranes (d‐PTFE) were bonded on the buccal surfaces of posterior teeth of each subject. All study subjects refrained from toothbrushing during the study period. Specimens were detached from the teeth at 4 and 24 hr and subjected to viability counting, confocal microscopy, and scanning electron microscopy. Plaque samples were harvested from neighboring teeth at baseline, 4, and 24 hr, as control. Wilcoxon signed rank test was applied.ResultsNo bond failure of the membranes was reported. Between the early and late time points, viable bacterial counts increased on all membranes, with no difference between the test and control. The number of Staphylococcus spp. decreased on the tooth surfaces and increased on both membranes overtime, with a significant difference compared to teeth. The total biomass and average biofilm thickness of live and dead cells were significantly greater at the d‐PTFE barriers after 4 hr.ConclusionThis study demonstrated that the e‐PTFE membrane was associated with a lesser degree of biofilm accumulation during the initial exposure compared to the d‐PTFE membrane. The present experimental setup provides a valuable toolbox to study the in vivo behavior of different membranes used in guided bone regeneration (GBR).

Vertical-guided bone regeneration with a titanium-reinforced d-PTFE membrane utilizing a novel split-thickness flap design: a prospective case series

ObjectivesTo evaluate the feasibility of a newly proposed minimally invasive split-thickness flap design without vertical-releasing incisions for vertical bone regeneration performed in either a simultaneous or staged approach and to analyze the prevalence of adverse events during postoperative healing.Materials and methodsFollowing preparation of a split-thickness flap and bilaminar elevation of the mucosa and underlying periosteum, the alveolar bone was exposed over the defects, vertical GBR was performed by means of a titanium-reinforced high-density polytetrafluoroethylene membrane combined with particulated autogenous bone (AP) and bovine-derived xenograft (BDX) in 1:1 ratio. At 9 months after reconstructive surgery, vertical and horizontal hard tissue gain was evaluated based on clinical and radiographic examination.ResultsTwenty-four vertical alveolar ridge defects in 19 patients were treated with vertical GBR. In case of 6 surgical sites, implant placement was performed at the time of the GBR (simultaneous group); in the remaining 18 surgical, sites implant placement was performed 9 months after the ridge augmentation (staged group). After uneventful healing in 23 cases, hard tissue fill was detected in each site. Direct clinical measurements confirmed vertical and horizontal hard tissue gain averaging 3.2 ± 1.9 mm and 6.5 ± 0.5 mm respectively, in the simultaneous group and 4.5 ± 2.2 mm and 8.7 ± 2.3 mm respectively, in the staged group. Additional radiographic evaluation based on CBCT data sets in the staged group revealed mean vertical and horizontal hard tissue fill of 4.2 ± 2.0 mm and 8.5 ± 2.4 mm. Radiographic volume gain was 1.1 ± 0.4 cm3.ConclusionVertical GBR consisting of a split-thickness flap and using titanium-reinforced non-resorbable membrane in conjunction with a 1:1 mixture of AP+BDX may lead to a predictable vertical and horizontal hard tissue reconstruction.Clinical relevanceThe used split-thickness flap design may represent a valuable approach to increase the success rate of vertical GBR, resulting in predicable hard tissue regeneration, and favorable wound healing with low rate of membrane exposure.

Use of NO‐resorbable dPTFE membranes in preservation of the alveolar ridge‐ a case report

Background: After the extraction, a biological remodeling phase of the alveolar ridge follows, resulting in resorption both vertically and horizontally. To a large extent, this has the effect of installing a dental implant in a correct 3D position. In order to maintain the width and height of the alveolar ridge, a large number of operative techniques for preserving the extraction wound are used. In our article, a preservation technique is presented using the NO-resorptive dPTFE membrane and xenograft. Aim/Hypothesis: Use of bone substitutes in combination with the NO-resorbable dPTFE membrane are examined, for preservation of the extraction socket. We expect to preserve the dimensions of the alveolar ridge in the vertical and horizontal direction in order to place the implant in the correct prosthetic position. Materials and Methods: At the University Dental Clinical Center “St. Pantelejmon – Skopje”, an intervention was performed for preservation of the alveolar ridge in the upper jaw after extraction, in projection of the premolar region. Alveolar preservation was performed using bovine xenograft (cerabone®, botiss biomaterials GmbH). Each preserved socket was covered with ultra-thin (˜0.08 mm) dPTFE membrane (permamem®, botiss biomaterials GmbH) and it was fixed with individual sutures (silk 3/0 Astra Med). The installed non-resorbable membrane was removed after 4 weeks without any additional surgery and the wound was left to heal freely, giving instructions to the patient to maintain oral hygiene by rinsing his mouth twice daily with 0.1% chlorhexidine gluconate. CBCT was performed before the time of tooth extraction and after 6 months from the application of the graft material. With this CBCT we measured the changes of the alveolar ridge and we accurately determined the extent of its dimensional remodeling. Results: Although the NO-resorbable membrane was left uncovered during wound healing, the patient showed no clinical symptoms such as pain, swelling, infection, allergic reaction, or loss. After removal of the membrane in the fourth week, a young granulation of NO-epithelial tissue was observed under the NO-resorbable membrane itself. Six months after the placement of the dental implants, complete healing and integration of the bone graft material was observed, and the performed CBCT images showed minimal remodeling in both horizontal and vertical direction of 1.5 mm. Conclusions and Clinical Implications: The use of NO-resorbable dPTFE membranes, which allow open healing of extraction wounds, in combination with bone substitutes of xenogenic origin, gives predictable and reliable results in the preservation of extraction wounds with minimal bone loss. Keywords: preservation of the alveolar ridge, NO-resorbable membrane

Antimicrobial effect of nanostructured membranes for guided tissue regeneration: an in vitro study

ObjectiveThe purpose of this in vitro study was to evaluate the antibacterial effect of a novel non-resorbable, bioactive polymeric nanostructured membrane (NMs), when doped with zinc, calcium and doxycycline. MethodsA validated in vitro subgingival biofilm model with six bacterial species (Streptococcus oralis, Actinomyces naeslundii, Veillonela parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans) was used. The experimental NMs, with and without being doped with doxycycline, calcium and zinc, were placed on hydroxyapatite (HA) discs. As positive control membranes, commercially available dense polytetrafluoroethylene (d-PTFE) membranes were used and, as negative controls, the HA discs without any membrane. The experimental, positive and negative control discs were exposed to a mixed bacterial suspension, at 37 °C under anaerobic conditions, during 12, 24, 48 and 72 h. The resulting biofilms were analyzed through scanning electron microscopy (SEM), to study their structure, and by quantitative polymerase chain reaction (qPCR), to assess the bacterial load, expressed as colony forming units (CFU) per mL. Differences between experimental and control groups were evaluated with the general linear model and the Bonferroni adjustment. ResultsAs shown by SEM, all membrane groups, except the NMs with doxycycline, resulted in structured biofilms from 12–72 hours. Similarly, only the membranes loaded with doxycycline demonstrated a significant reduction in bacterial load during biofilm development, when compared with the control groups (p < 0.001). SignificanceDoxycycline-doped nanostructured membranes have an impact on biofilm growth dynamics by significant reducing the bacterial load.

D-Ptfe Cytoplast® membranes in guided bone regeneration in implantology

The vertical bone increase of alveolar rim is important to obtain good results in rehabilitation with prostheses on implants. This Literature Review sought articles that treat bone increases of alveolar edges using Cytoplast® membranes, seeking to evaluate the resistance to bacterial penetration and capacity to create and maintain space. For this, a literature review was made on the Pubmed and Google scholar search platforms. The researches analyzed found similar results between d-PTFE membrane, titanium meshes and e-PTFE membranes, both in bone gain and bone quality. The space maintenance capacity was evident in the articles in which the titanium reinforced membrane was used. The d-PTFE membrane presented a greater capacity of exposure to the oral environment without compromising the graft material. The authors researched in this study found that titanium-reinforced d-PTFE membranes for bone augamble alveolar rim increases are viable and allow a certain period of exposure to the oral environment without graft contamination. Further studies are needed with the Cytoplast® d-PTFE membrane to explore its characteristics with vertical bone augmentation procedures.

Effect of Induced Membrane on Guided Bone Regeneration in an Experimental Calvarial Model.

The aim of this study was to evaluate the effect of induced membrane on guided bone regeneration and to compare its effect with poly-tetra-flourur-ethylene (PTFE) membrane and collagen membrane. Sixteen white Vienna rabbits were used for experiments. Initially 1 defect was created on the parietal bone of all animals and cement was placed inside the defects. After 8 weeks, the bone cements were removed, without damaging the induced membrane formed in the defect cavity. And then 2 more defects were created. All defects were filled with xsenogenic graft materials and were covered with newly formed induced membrane, d-PTFE membrane and collagen membrane. Eight animals were sacrificed at 4th week and other 8 animals were sacrificed at 8th week and all bone specimens were histologically evaluated. New bone formation and bone marrow ratios were significantly higher in induced membrane and d-PTFE membrane group compared to collagen membrane group (P < 0.05) at 4th week. Mature bone ratios were significantly higher in induced membrane and d-PTFE membrane group compared to collagen membrane group (P < 0.05) at 8th week. The best CD31 value was detected with d-PTFE membrane group at 4th week and with induced membrane at 8th week. Induced membrane can act as a strong barrier membrane and stimulate bone regeneration. Induced membrane technique can be accepted as a good alternative for the reconstruction of critical size defects in maxillofacial region.

Open-Healing Socket Preservation with a Novel Dense Polytetrafluoroethylene (dPTFE) Membrane: A Retrospective Clinical Study.

Background and objectives: Non-resorbable dense polytetrafluoroethylene (dPTFE) membranes are widely used for regeneration procedures, alone or in combination with particulate materials. The aim of this work was to examine the efficacy of a newly developed dPTFE membrane in the management of extraction socket healing. Materials and Methods: The extraction premolar sockets of 44 patients (20 men and 24 women) were preserved. One group received prosthetic rehabilitation with a fixed partial denture (FPD) (PROS group, N = 19) and a second group received immediate implant placement (IMPL group, N = 25). The PROS group sockets were augmented with a bovine derived xenograft and covered with a newly developed dPTFE membrane prior to FPD rehabilitation. Results: In the IMPL group, socket preservation was combined with immediate implant placement. Before (T0) and 6 months after surgery (T1), horizontal and vertical dimensions were measured with customized stents. No significant differences in alveolar bone loss from T0 to T1 were observed between the PROS and IMPL groups in the horizontal dimension for any tooth type. There was a significant difference in alveolar bone loss from T0 to T1 between the two groups for only single-rooted maxillary premolars in the vertical dimension. Conclusions: The use of the examined new dPTFE membrane consistently led to the preservation of hard tissue in the extraction sites.

Experimental assessment of histological and biological properties of the induced membrane and the membrane formed around the d-PTFE membrane: A pilot study

BackgroundThe aim of this prospective pilot study is to find answers to the following question: In the treatment protocol of open membrane technique defined by Funakoshi, do the histological and biological properties of the tissue that has already covered the graft surface following the removal of the d-PTFE membrane resemble those properties of induced membrane? Material and methods4 male, white Vienna rabbits were used for experiments. Bicortical and 10mm in diameter four bone defects were created on each calvarial bone. 2 rabbits (8 defects) were accepted as group I and other 2 rabbits (8 defects) were accepted as group II. Bone cement was placed into the all-defect in group I. 8 defects were filled with Bi-Oss graft material and covered with d-PTFE membranes in group II. After 8 weeks, sacrifice of the rabbits was performed. In group I, without damaging the formed membrane around it, the bone cement was removed from the defects and the achieved membrane was sent to the pathology department. In group II, the thin film layer that formed under the d-PTFE membrane was sent for histological evaluations. Inflammation, edema, foreign body reaction, synovial-like epithelium existence, thickness, vascularisation (CD31, VEGF), fibrosis were assessed. ResultsInflammation, fibrosis and thickness measurements are significantly different between the groups (P<0,05) and for these parameters, the mean of d-PTFE group (Group II) is significantly higher than the mean of the induced-membrane group (Group I). There isn’t any significant difference for other parameters. ConclusionThe morphological characteristics of membranes of the two groups were similar. There was a cell-rich, vascularised tissue with fibrous structures; fibroblasts, myofibroblast, and collagen, orientated parallel to the cement.

The Use of a Non-Absorbable Membrane as an Occlusive Barrier for Alveolar Ridge Preservation: A One Year Follow-Up Prospective Cohort Study.

The aims of this study were to obtain preliminary data and test the clinical efficacy of a novel nonporous dense-polytetrafluoroethylene (d-PTFE) membrane (permamem®, botiss) in alveolar ridge preservation (ARP) procedures with a flapless approach. A traumatic extraction was performed in the premolar maxillary area, and a d-PTFE membrane was used to seal the alveolar cavity: no biomaterial was used to graft the socket and the membrane was left intentionally exposed and stabilized with sutures. The membrane was removed after four weeks and dental implants were placed four months after the procedure. The primary outcome variables were defined as the dimensional changes in the ridge width and height after four months. A total of 15 patients were enrolled in this study. The mean width of the alveolar cavity was 8.9 ± 1.1 mm immediately after tooth extraction, while four months later a mean reduction of 1.75 mm was experienced. A mean vertical reduction of 0.9 ± 0.42 mm on the buccal aspect and 0.6 ± 0.23 mm on the palatal aspect were recorded at implant placement. Within the limitations of this study, the d-PTFE membrane proved to be effective in alveolar ridge preservation, with the outcomes of the regeneration not affected by the complete exposure of this biomaterial.

Çekim Soketlerinin Ogmentasyonunda Primer Kapamaya Karşı Açık Membran Tekniği

Objectives: Funakoshi is the first one who reported 'Open Barrier Membrane' technique by using non-expanded, highdensity polytetrafluoroethylene(d-PTFE) membrane in 2005. d-PTFE membranes are impenetrable for bacteria invasion because of its surface characteristics and surgeon can leave the d-PTFE membrane intentionally exposed. The objective of this study was to investigate the clinical results of 'Open Barrier Membrane' technique in Guided Bone Regeneration (GBR) of the extraction sockets by using xenogenic bone graft and d-PTFE membranes. In this clinical study, open barrier membrane technique was compared to GBR technique. The comparison was made between the cases where the primary coverage of extraction site was obtained and the cases who completed the 6-month recovery period without exposure in terms of total bone gain. Material and Methods: Fifteen patients who were reported to have exposure in incision line during 6-month recovery period were included in open membrane group as study group (Group A). Fifteen patients who completed the 6-month recovery period without exposure were analyzed in primary coverage group as control group (Group B). The main groups were also divided into subgroups as horizontal and vertical augmentation. The amount of total bone gain was statistically compared between the groups based on the cone beam computerized tomography measurements. Results: Vertical and horizontal bone gain amounts (the main outcome variable) were statistically compared between Group A and B. There was no statistically significant difference between these groups in terms of bone gain (p=0.237 for comparison of vertical augmentation; p=0.482 for comparison of horizontal augmentation). Conclusion: Open barrier membrane technique can be considered as an alternative minimal invasive technique for both horizontal and vertical alveolar augmentation procedures.

Microbiological and FE-SEM Assessment of d-PTFE Membrane Exposed to Oral Environment after Alveolar Socket Preservation Managed with Granular nc-HA

The aim of this study was to analyze, by the aid of microbiological analysis and the field emission scanning electron microscopical (FE-SEM) analysis, the role of high-density polytetrafluoroethylene (d-PTFE) membranes in avoiding the microbial colonization of a nanocrystalline hydroxyapatite (nc-HA) bone graft and the involvement of this colonization in the healing process. Six patients underwent extraction of unrecoverable teeth, and a socket preservation technique was carried out with nc-HA synthetic bone graft and then covered with a d-PTFE membrane. After 28 days from surgery, FE-SEM analysis and BioTimer assay technique to assess the microbiological count of streptococci species were carried out. Data were collected and analyzed by the Student's t test (confidence interval: 95%). The mean amount of bacteria measured on the upper side of the membrane was 6.52 ± 0.50 CFU, while on the lower side, it was 6.59 ± 0.40 CFU. Significant differences were not found between the two sides of the membrane or between the different sectors (p > 0.05). The FE-SEM analysis revealed structured biofilms on both sides of the membrane: species of cocci, bacilli, and fusobacteria were recognizable in occasional settled vegetations. Since the amount of bacteria found was low, the improved impermeability of the d-PTFE membrane permitted the healing process to proceed uneventful and without signs of infection or inflammation. The infection of the graft site could lead to a failure of the socket preservation technique which could delay or compromise the rehabilitation following procedures. The use of d-PTFE can improve the bone regeneration thanks to its antimicrobial properties.

Periosteal Inhibition Technique for Alveolar Ridge Preservation as It Applies to Implant Therapy.

Alveolar ridge preservation procedures have been shown to significantly reduce the loss of ridge dimension of an extraction socket. As of yet, none of the alveolar ridge preservation techniques have been proven totally effective in preserving ridge morphology. The Periosteal Inhibition technique for alveolar ridge preservation involves placing a high-density polytetrafluoroethylene (d-PTFE) membrane between the periosteum and the buccal bone plate of an extraction socket. The authors hypothesize that the nonresorbable d-PTFE membrane, because of its much smaller pore diameter as compared to the size of the osteoclast precursor cells, inhibits the migration of the osteoclast precursor cells from the periosteum to the bony surface and, subsequently, their fusion to form osteoclasts. As a result, osteolytic activity on the outer surface of the socket is inhibited. The Periosteal Inhibition technique for alveolar ridge preservation is presented along with immediate implant treatment results using this treatment concept. The resulting stable ridge dimensions in these cases demonstrate a possibility that the d-PTFE membrane may effectively prevent modeling of the extraction socket by inhibiting the formation of osteoclasts on the outer bony surface.

Socket Preservation Using a (Dense) PTFE Barrier with or without Xenograft Material: A Randomized Clinical Trial.

When alveolar preservation procedures are not performed after tooth extraction, aesthetic and functional impairment could occur. Guided bone regeneration using polytetrafluoroethylene (PTFE) membranes has proven to be a simple alternative treatment that results in good maintenance of the alveolar bone for mediate/late implant placement. Therefore, this study compared the effect of alveolar preservation with the use of dense PTFE membranes, with and without xenograft material by Computerized tomography-based body composition (CTBC) analysis, after four months of the socket preservation procedure. A total of 29 teeth indicated for extraction. In the test group, the sockets were filled with bone graft biomaterial and subsequently coated with a dense PTFE membrane. In the control group, the sockets were filled with the blood clots and subsequently coated with a dense PTFE membrane. The results we found on the changes of the bone width and height after the procedures were: buccal plate: control group 0.46 mm, test group 0.91 mm; alveolar height: control group −0.41 mm, test group 0.35 mm; cervical third: control group −0.89 mm, test group −0.11 mm; middle third: control group −0.64, test group −0.50; and apical third: control group 0.09 mm, test group −0.14 mm. The use of a xenograft in conjunction with d-PTFE membranes proved to be superior to the use of the same membrane and blood clot only in regions of the crest, middle third, and alveolar height.