Effect of ship-shaped expanded polytetrafluoroethylene nasal prosthesis in rhinoplasty / 中华医学美学美容杂志

Objective:To investigate the effect of ship-shaped expanded polytetrafluoroethylene (e-PTFE) nasal prosthesis in rhinoplasty.Methods:From February 2016 to June 2021, 86 patients, including 9 males and 77 females, aged 18-47 (24±5) years old, were admitted to Chengdu High-tech Zone Xinyuerong Medical Aesthetic Clinic for cosmetic treatment of rhinoplasty. All patients underwent rhinoplasty with the application of ship-shaped e-PTFE and autologous cartilage. The postoperative complications, glabellar fullness, inverted brow triangle, nasal polygon aesthetic shape and patient satisfaction were evaluated. These data were measured and analyzed, including the nasal length, nasal tip height, nasal frontal angle and nasal facial angle before and after the operation.Results:In 86 patients, the incision healed in one stage after surgery, and 8 cases had nasal vestibular scar hyperplasia. All patients were followed up for 1-5 years: 84 cases obtained satisfactory nasal morphology, and 2 cases recovered naturally after adjusting and lowering the prosthesis height half a year after surgery because the interbrow area was too full. 74 patients (86%) were very satisfied, 10 cases (11.6%) were satisfied. The nasal length was (4.07±0.20) cm, the nasal tip height was (2.66±0.36) cm, the nasal frontal angle was (106.42±8.04)°, and the nasal face angle was (15.90±0.85)°before operation. The nasal length was (4.23±0.20) cm, the nasal tip height was (2.59±0.26) cm, the naso-frontal angle was (113.69±6.34)°, and the naso-facial angle was (21.57±0.78)° at eighteen months after operation. There were statistically significant differences in nasal length, naso-frontal angle and naso-facial angle ( t=-5.51, -5.96, -52.31, P<0.01), but no statistically significant differences in nasal tip height ( t=1.47, P=0.146). Conclusions:The ship-shaped e-PTFE can be shaped to reflect the aesthetic of the nose dorsum, which is similar to the anatomical structure of the nose dorsum, increase the stability and authenticity of the prosthesis, and is worthy of clinical application.

Clinical effect of integrated prosthesis on eyebrow arch augmentation / 中华医学美学美容杂志

Objective:To explore the feasibility and advantages of integrated prosthesis of expanded polytetra-fluoroethylene (e-PTFE) in eyebrow arch augmentation.Methods:The clinical data of 45 patients with low or flat brow arch and glabellar zone from June 2019 to October 2020 in Chengdu High-tech Zone Xinyuerong Medical Aesthetic Clinic were analyzed retrospectively, in which it included 45 women, whose ages ranged from 20 to 39 years with average 29.8 years. Forty-three cases underwent primary surgery, and 2 cases underwent repair. The e-PTFE was sculpted to be personalized integrated prosthesis according to the shape of the patient's eyebrow arch and glabellar zone. The incision was designed on the medial and lateral sides of the lower margin of the bilateral eyebrow to avoid the supraorbital foramen, and the lacunae were striped under the frontal periosteum, and the two sides were connected to cover the glabellar zone and inverted triangle area between the eyebrows. The carved e-PTFE was implanted into one side and pulled out from the other side. The prosthesis was smoothed by Venn pliers of the ventral and dorsal sides.Results:The 45 patients in this group were followed up for 6-18 months. The incisions of all the patients were healed Ⅰ/A, and the scar of the incisions was concealed. Slight scalp numbness occurred in 4 patients and returned to normal 3 months later. The prosthesis in the glabellar zone appeared in 1 case 3 months after operation and returned to normal after reoperation. The symmetry, radian, fullness, convexity and tactility of bilateral eyebrow arch were all satisfactory in 45 cases. 39 cases were very satisfied, accounting for 86.7%; 6 cases (13.3%) were satisfactory. The sagittal distance of the anterior surface of the cornea to the soft tissues overlying the supraorbital rims was (2.02±1.72) mm preoperatively and (6.5±1.19) mm in the last follow-up. The difference was statistically significant ( t=14.49, P<0.01). Conclusions:This design of integral e-PTFE in eyebrow arch augmentation is safe, effective and easy to operate. It can significantly increase the bony beauty and stereoscopic sense of the eyebrow arch and glabellar zone, effectively deepen the eye socket, improve the eye protrusion, and reduce the risk of asymmetry and prosthesis displacement, and therefore it is one of the ideal methods for eyebrow arch augmentation.

Application of expanded polytetrafluoroethylene in filling nasal base / 中华医学美学美容杂志

Objective To investigate the effect and safety of PTFE filling on correction of nasal basal treatment of midfacial sag.Methods Top of the vestibular sulcus groove was cut along the alveolar mucosa under direct maxillary periosteum,and then face inward in depression and the side line of the scope of subperiosteal separation from near to the medial nasal spine and the lateral side of pyriform aperture;range of separation was the same of both sides as marked before operation,slightly larger than the prosthesis;then the arc being carved,which was consistent with the nasal triangle expansion,was implanted into sub-periosteal site along pear-shaped arc edge of the hole placement and the prosthesis was fixed;as the appearance was satisfied,the incision was sutured.Results Clinical follow-up lasted for 6 months,and all the wound healing was well in primary intention without infection,implant exposure and other complications and facial expressions were natural.The filled results were satisfactory.Conclusions For correction of midfacial depression without need of osteotomy,nasal application of PTFE filling is simple with good efficacy and it is worth promoting.

The Clinical Effect of Micro-Multiporous Expanded Polytetrafluoroethylene Insertion for Recurrent Pterygium

PURPOSE: To investigate the clinical effect of micro-multiporous e-PTFE insertion for severe recurrent pterygium with symblepharon. METHODS: The present study included a total of 13 cases of recurrent pterygium associated with symblepharon, motility restriction and diplopia which had undergone micro-multiporous e-PTFE insertion after pterygium excision, 0.02% mitomycin C application, human amniotic membrane transplantation (AMT) and/or conjunctivo-limbal autograft (CLAU) between September 2010 and February 2011. One month after surgery, the inserted e-PTFE was removed. Recurrence of pterygium and symblepharon, motility restriction, diplopia and injection of ocular surface were evaluated for 11.92 +/- 1.32 months of mean follow-up period. RESULTS: Pterygial recurrence was not observed in 12 out of 13 eyes, and the 1 eye which recurred showed conjunctival recurrence. No postoperative symblepharon recurrence was observed in any of the 13 eyes. Diplopia and motility restriction disappeared in 11 out of 13 eyes, and were improved in the other 2 eyes. VAS (Visual Analogue Scale) injection scores in the wound site decreased after surgery in all patients. CONCLUSIONS: Micro-multiporous e-PTFE insertion combined with mitomycin C application, AMT and CLAU can be a useful surgical method to lower the postoperative recurrence rate and to improve the pterygium-related symptoms in severe recurrent pterygium.

Autologous nasal septal cartilage combined with expanded-polytetrafluoroethylene in the secondary nasal deformity correction surgery of postoperative cleft lip / 中华医学美学美容杂志

Objective To correct the nasal deformities of cleft lip by expanded-polytetrafluoroe thylene (e-PTFE) combined with autologous nasal septal cartilage.Methods e-PTFE was placed nearby verge of anterior nasal aperture to raise the fundament of nose.Autologous nasal septal cartilage was harvested and combined with e-PTFE to form a sandwich structure.Nasal tip and collapsed nasaI alar were repaired by this method.Results Fifty cases were treated by this method and 42 cases were followed up for about one year.The results were satisfying.The contour of the nose was similar to normal.Only 3 cases were relapsed after one year.Conclusions e-PTFE combined with autologous nasal septal cartilage is an ideal method to correct nasal deformities of cleft lip.

Guided bone regeneration using two types of non-resorbable barrier membranes

INTRODUCTION: Guided bone regeneration (GBR) is a common procedure for the treatment of bone defects and bone augmentation. The non-resorbable barriers are well-documented barriers for GBR because of their stability and malleability. However, few GBR studies have focused on the different types of non-resorbable barriers. Therefore, this study examined the clinical results of different non-resorbable barriers for GBR; expanded polytetrafluoroethylene (e-PTFE) (TR-Gore Tex, Flagstaff, AZ, USA), and high-density polytetrafluoroethylene (d-PTFE) (Cytoplast membrane, Oraltronics, Bremen, Germany). MATERIALS AND METHODS: The analysis was performed on patients treated with GBR and implant placement from January 2007 to October 2007 in the department of the Seoul National University Bundang Hospital. The patients were divided into two groups based on the type of non-resorbable barrier used, and the amount of bone regeneration, marginal bone resorption after prosthetics, implant survival rate and surgical complication in both groups were evaluated. RESULTS: The implants in both groups showed high survival rates, and the implant-supported prostheses functioned stably during the follow-up period. During the second surgery of the implant, all horizontal defects were filled with new bone, and there was no significant difference in the amount of vertical bone defect. CONCLUSION: In bone defect areas, GBR with non-resorbable barriers can produce favorable results with adequate postoperative management. There was no significant difference in bone regeneration between e-PTFE and d-PTFE.

The effect of human demineralized freeze-dried xenograft on vertical bone formation in beagle dogs / 대한치주과학회지

PURPOSE: The purpose of this study was to evaluate exophytically vertical bone formation in the mandibular premolar area of beagle dogs by the concept of guided bone regeneration with a titanium reinforced e-PTFE membrane combined with human demineralized freeze-dried bone. MATERIALS AND METHODS: Four one-year old beagle dogs were divided into control and experimental group. All mandibular premolars were extracted and surgical vertical defects of 5 mm in height were created in the extracted sockets. At 8 weeks after the extraction, TR e-PTFE membrane sized with 8 mm in length, 5 mm in width, and 4 mm in height was placed on the decorticated mandible, fixed with metal pins and covered with full-thickness flap and assigned as control group. In experimental group, decorticated mandibule was treated with TR e-PTFE membrane and human demineralized freeze-dried bone. The animals were sacrificed at 16 weeks after the regenerative surgery, and new bone formation was assessed by histomorphometric as well as statistical analysis. RESULTS: Average of new bone formation was 38% in the control group, whereas was 25% in the experimental group (p<0.05). Average of connective tissue formation was 42% in the experimental group, whereas was 30% in the control group (p<0.05). The lamellar bone formation with haversian canals was observed in the both groups. In the experimental group, the particles of human demineralized freeze-dried bone were observed after 16 weeks and complete resorption of graft was not observed. CONCLUSION: On the basis of these findings, we conclude that titanium reinforced e-PTFE membrane may be used alone for vertical guided bone regeneration, but demineralized freeze-dried bone has no additional effect on vertical guided bone regeneration.

Polytetrafluoroethylene as a Spacer Graft for the Correction of Lower Eyelid Retraction

PURPOSE: To evaluate the efficacy of porous expanded polytetrafluoroethylene (e-PTFE, Goretex (R) ) containing large pores made with a 21-gauge needle as a graft for the correction of lower lid retraction. METHODS: e-PTFE grafts were implanted between the tarsus and lower lid retractor via a transconjunctival approach with/without amniotic membrane transplantation, or via a transcutaneous approach. Rabbits were examined and assessed for corneal and conjunctival complications and for e-PTFE graft status. Rabbits were sacrificed for a histological study at 8 weeks postoperatively. RESULTS: e-PTFE grafts were uniformly extruded 3 weeks postoperatively in eyelids operated on via the transconjunctival approach. However, rabbits operated on via the transcutaneous approach demonstrated e-PTFE graft retention; in addition, dense fibrovascular ingrowths into the large pores of e-PTFE were observed histologically. CONCLUSIONS: e-PTFE is a good substitute for other graft materials as a spacer in lower lid retraction operations, especially as an interpositional graft using a transcutaneous approach.

Clinical and histopathological study using platelet-rich plasma and bone graft in the localized alveolar bone defects / 대한치주과학회지

Alveolar ridge defects may limit or restrict placement of implants. The purpose of this study was to evaluate clinical and histopathologic results which occur following guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane in the localized alveolar bone defects. Ten patients who required guided bone regeneration in implant placemnet, were slelected. Alveolar crest height and width were measured at baseline and, afer 2nd surgery 5 months later At 5 months , we obtained histopathological results as follows: 1. Alveolar crest height was an average of 8.20+/-3.74 mm preoperatively and decreased to an average of 7.40 +/-1.84 mm postoperatively. There was no significant difference. 2. Alveolar crest width was an average of 4.25+/-2.03 mm preoperatively and significantly increased to an average of 7.20+/-2.44 mm postoperatively (P<0.01) 3. The change of Alveolar crest height and width were 0.80+/-1.40 mm, 2.95+/-1.09 mm 4. Histopathological evaluations revealed new bone formation with graft material and laminated bone containing the presence of osteocyte-like cell In conclusion, guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane would provide a viable therapeutic alternative for implant placement in the localized alveolar defect or implant failure

Reconstruction of Lateral Capsular Ligament of Temporomandibular Joint with E-PTFE(Gore-tex(R)) Patch

The lateral capsular ligament of temporomandibular joint(TMJ) prevents mandibular condyle from lateral displacement in case of fractures related with condyle. When the condylar fracture with lateral extracapsular displacement occurs, open reduction and reconstruction of capsular ligament must be considered. However, many patients exhibit limitation of functional movements of the TMJ after such surgery. This may be a result of myositis, myospasm, fibrosis of bilaminar zone, adhesion of TMJ capsule. When the joint problem occurs, non surgical treatment must be attempted firstly. But if it fails, the surgical reconstruction must be considered. We reconstructed the lateral capsular ligament of TMJ with E- PTFE(Expanded Polytetrafluoroethylene, Gore-tex(R)) patch after removing scar tissues and adhesions. This surgical method showed improvements in movement as well as the pain of the joint. No side effect has detected from occlusion for about 2 years. There was no foreign body reaction or irritation to the capsule, since E-PTFE was biologically inert. We believe that the E-PTFE patch could be used as primary material of capsular ligament of TMJ reconstruction, insertion material in high tensioned capsule and reinforcement material in weakened capsule.

The Effects of Placement of Silicone Tube and e-PTFE Stent in External Dacryocystorhinostomy

PURPOSE: To determine the surgical results of bicanalicular silicone tube and e-PTFE (expanded polytetrafluoroethylene) stent in external dacryocystorhinostomy without flap. METHODS: Sixteen patients had been placed with bicanalicular silicone tube and e-PTFE stent and 17 patients with silicone tube only in external dacryocystorhinostomy without flap. We examined the presence of epiphora symptom, passage of dye, and inflammatory change or granuloma formation of nasal mucosa at postoperative 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 24 weeks. RESULTS: Success rate was higher in double stent group (81.3%) than that in control group (76.5%). But there was no statistically significant (difference between two groups. p=0.085). At nasal endoscopic examination, one case (6.3%) of granuloma was noted in double stent group, and two cases (11.8%) in control group. Membraneous obstruction was not observed in double stent group but one case (5.9%) in control group. CONCLUSIONS: In case of structural deteriolation of midface including nasolacrimal duct, placement of bicanalicular silicone tube with e-PTFE stent may be an useful method in external dacryocystorhinostomy without flap.

Intraocular Pressure Change after Glaucoma Implant Surgery with Releasable suture

PURPOSE: To find the factor that affects the long-term intraocular pressure after glaucoma implant surgery with releasable suture. METHODS: We retrospectively reviewed the medical records of the 33 patients (36 eyes) who had undergone glaucoma implant surgery with our own expanded-Polytetrafluoroethylene (e-PTFE) membrane-tube implant with temporary closure of the tube by releasable suture. Data such as timing of suture release, IOP's before and after surgery and the amount of pressure change during follow-up were collected, and we tried to find the factor that influenced the IOP at the last visit. RESULTS: The preoperative IOP was 43.2+/-14.6 mmHg and the suture was released at day 17.9+/-9.5 after surgery. The IOP just before the release of suture was 33.5+/-17.1 mmHg. The pressure was dropped to 15.1+/-13.7 mmHg, measured at 30 minutes after the release of the suture. The IOP was stabilized to 14.9 +/-9.5 mmHg at 12.2+/-7.0 days after the release. The average follow-up was 32.8+/-26.3 months and the IOP at the last visit was 17.3+/-10.5 mmHg. Four eyes (11%) had hypotony (IOP less than 8 mmHg) before release of the suture, thirteen eyes (41%) showed hypotony 30minutes after release, and three eyes(8%) showed hypotony at the last visit. Multiple linear regression analysis revealed that the IOP at 30 minutes after release of the suture had a positive correlation with the IOP at the last visit (r=0.642,p=0.000). CONCLUSIONS: In the membrane-tube implant surgery for the refractory glaucoma, the releasable suture echnique is helpful to prevent the early postoperative hypotony. By measuring early post-release IOP after implant surgery with releasable suture technique, we might predict the behavior of long term IOP change; the lower post-release IOP, the better long-term pressure control.

Histological changes of domestic e-PTFE implanted into subcutenous tissue of rat / 中华医学美学美容杂志

Objective To investigate the relative histological change of transplanted domestic expanded polytetrafluoroethylene (e-PTFE), which were treated with different methods, in order to offer the referential data for clinical application. Methods e-PTFE treated with different methods was transplanted into subcutaneous tussue of rat. The samples harvested according to time sequence were examined by using histological and histochemical methods. Dynamic change of the structure between the e-PTFE and it's surrounded tissue was investigated based on the examination. Results Cell and tissue were observed on the inside of all the e-PTFE including the control group and the experiment groups. Heavy cell infiltration on the 3rd day was the most significant in control group, and the quantity of tissue ingrowth was also the most until the 28th day. The next was trimming group. The quantity of both cell infiltration and the tissue ingrowth in high pressure steamed group and forceps squeezed group were less than that in other groups. Conclusion Cell infiltration into domestic e-PTFE is significantly achieved since 72 hrs and fibrovascular ingrowth since the 7days after implanted e-PTFE under subcutaneous tissue of the rat. Different treatment methods of e-PTFE can affect the speed of tissue ingrowth into the e-PTFE, which could be a reference for clinic application of e-PTFE.

Intermediate-term Result of e-PTFE Membrane Implant Surgery for Refractory Glaucomas

Recently, various tube-shunt implants have been used in treating refractory glaucomas.They have large volumed reservoir portion made of hard materials.We made a new implant with soft and freely malleable membrane[expanded polytetrafluoroethylene, e-PTFE]as a reservoir portion attached to the conventional silicone tube. Based on the encouraging result from experimental animal study, we performed a clinical trial for the membrane-tube implant.We performed Glaucoma Tube-Shunt Implant surgery using double layers of e-PTFE membrane and silicone tube with its one end fixed between the two layers.The subjects had refractory glaucomas without useful vision who visited our hospital from May 1991 to Sep.1995. There were 40 eyes of 37 patients and their mean follow-up period was 32.6 months.We could control the IOP within 6~21 mms of mercury in 26 eyes[65.0%, Success].In remaining 14 eyes, we could not control the IOP or additional surgery was needed to control the IOP or treat severe complications[35.0%, Failure].The Kaplan-Meier Survival for IOP control was 78.4% at 1 yr, 71.6%at 2 yr, and 60.3%at 3 yr.The complications were similar to those of other commercially available Glaucoma implants. This new implant is made of soft, freely malleable membrane for the reservoir portion with small volume which can be inserted with smaller incision on the conjunctiva with less complication.We have obtained comparable result from this membrane-tube implant to other implants, and it may be considered as an another substitute for the treatment of refractory glaucomas.

Volume Flow Measurement of Autogenous and PTFE Graft Arteriovenous Fistulae for Hemodialysis of Chronic Renal Failure Patients

BACKGROUND: When it is difficult to insure adequate blood vessels, an expanded polytetrafluoroethylene (e-PTFE) graft has been accepted as an alternative although its long-term patency is not equal to that of an autogenous arteriovenous fistula (AVF) for the purpose of performing hemodialysis. There being no hemodynamic guidelines for creating an autogenous or e-PTFE AVF, we prospectively investigated the difference in blood flows between autogenous and e-PTFE AVFs after internal AVF creation in order to identify an ideal AVF. METHODS: We performed color doppler ultrasonography on 15 patients who experienced AVF creation between December 1997 and December 1998 at the Wallace Memorial Baptist Hospital in Pusan and compared the volume flow per minute, the peak systolic velocity, and the cross-sectional area between an autogenous and an e-PTFE AVF. RESULTS: Eight (8) patients experienced an autogenous vein AVF creation, and seven (7) patients experienced an AVF creation using 4x6 mm graded e-PTFE (Impra(R)). 1. Average volume flow: 1611.87 +/-687.52 mL/min for autogenous AVFs and 1725.28+/-269.06 mL/min for e-PTFE AVFs (p=0.67). 2. Average peak systolic velocity: 128.98+/-52.83 cm/sec for autogenous AVFs and 81.71+/-8.93 cm/sec in e-PTFE AVFs (p=0.04). 3. Average cross-sectional area: 0.23+/-0.10 cm2 for autogenous AVFs and 0.34+/-0.02 cm2 for e-PTFE AVFs (p=0.02). 4. There were no postoperative complications, such as venous hypertension or distal ischemia, except for one puncture-site infection. CONCLUSIONS: There was no significant difference in volume flows between autogenous AVFs and 4x6 mm graded e-PTFE graft AVFs after internal AVF creation. In the e-PTFE graft AVFs, the cross-sectionalarea was greater and the peak systolic velocity was smaller compared with those of autogenous AVFs. These results suggest that, in e-PTFE AVF creation in order to maintain on adequate minute volume flow, it is important to minimized the cross-sectional area of the outflow vessel where the lower compliance of the e-PTFE graft increases outflow resistance. Also, we conclude that choosing the appropriate blood vessels and using a meticulous surgical technique are mandatory in establishing optimal hemodynamics for arteriovenous fistulae.

Mitomycin C in anterior chamber tube shunt to a surgical membrane

To increase the success rate of intraocular pressure control in recalcitrant glaucoma, anterior chamber tube shunt to a surgical membrane (ACTSSM) surgery using silicone tube and expanded polytetrafluoroethylene (e-PTFE) can be performed. Applying mitomycin C (MMC) during ACTSSM surgery may increase the success rate by decreasing the fibroblast proliferation and collagen in the fibrous capsule. To evaluate the effects of MMC on the fibrous capsule formed after ACTSSM surgery, operations were performed on 18 white rabbits. Nine rabbits were treated with 0.04% MMC solution on the episclera for 5 minutes before ACTSSM (group A) and the others were not treated (group B). At postoperative 2, 4 and 8 weeks successively, 6 eyes of the 3 rabbits were enucleated from each group. Light microscopic examinations were performed after hematoxylin

Use of e-PTFE Membrane for Glaucoma Drainage Surgery

A new glaucoma drainage implant, expanded polytetrafluoroethylene(e-PTFE) membrane implant, and e-PTFE-silicone tube implant were used in 11 eyes of 11 patients with recalcitrant glaucomas including neovascular glaucoma. After an average follow-up of 13 months, intraocular pressures(IOPs) decreased to the level ranging from 10 to 20mmHg in all the eyes. Five patients were not on antiglaucoma medication. Four patients required one beta blocker and/or pilocarpine. The remaining two patients still required the maximum tolerated medical therapy and were considered to have a failed drainage surgery. A temporary obstruction of the drainage tube occurred in 2 eyes with neovascular glaucoma which developed a minimal hyphema and fibrinous aqueous after surgery. Postoperative hypotony and shallow anterior chamber developed in 4 eyes, but their situations were not dangerous. The patients each had a filtration bleb postequatorially after surgery. These blebs disappeared one to seven months later. In spite of the presence of a filtration bleb, 7 eyes developed an increased IOP temporarily. The required conjunctival incision for installation of an e-PTFE drainage implant was less than 90 degrees and the overall surgical procedures seemed to be simple.

A membranous drainage implant in glaucoma filtering surgery: animal trial

This experiment used 30 rabbits (40 normal eyes) to determine the applicability of an expanded polytetrafluoroethylene (e-PTFE) surgical membrane as a glaucoma seton. The e-PTFE membrane had 0.1 mm thickness and was cut into T-shaped pieces measuring about 2x7 mm. One end of the implant was introduced into the anterior chamber through a sclerectomy opening and the other ends were allowed to extend from the Iamellar scleral flap into the subconjunctival space. During the follew-up at the end of 8 weeks, all the eyes with an implant showed an apparent filtering bleb, while only one of 6 eyes that had undergone a trabeculectomy alone did. The location of the created filtering blebs depended on the implant position. Pestoperative inflammatory changes were unremarkable. Histologic examinations reyealed a tissue-free cystic space surrounding the e-PTFE implants which maintained their original color, thickness, pliability and size. Transmission electron microscopy showed few myofibroblast-like cells in the fibrous wall containing the implant. With scanning electron microscopy, the internal end of the implant strip had a clean surface and no adhesions to adjacent structures of the anterior chamber angle. The corneal endothelial cells were intact in the area close to the tip of the implant. Considering the clinical and histologic findings, it appeared that the e-PTFE was acceptably innocuous in the anterior segment of the eye and a convenient material as a glaucoma seton.

THE INFLUENCE OF POLYTETRAFLUOROETHYLENE MEMBRANE ON CELL GROWTH OF PERIODONTAL MEMBRANE AND EXPERIMENTAL REGENERATION OF PERIODONTAL TISSUE / 解放军医学杂志

The effects of polytetrafluoroethylene (e PTFE) membrane on periodontal ligament cell (PDLC) growth and periodontal tissues and new cement regeneration were studied, and the prospects of clinical application of e PTFE membrane were discussed. The results showed that PDLC grew well on the e PTFE membrane and no toxicity or inhibition was found. Close adhesion of the cells to the membrane was observed by scanning electron microscope. Histological studies suggested that the peculiar porous structure of e PTFE membrane protects and promotes healing of alveolar bone defect when the membrane edge was sealed perfectly on the crown side,exhibiting inhibition of growth of epithelium towards tooth root. The membrane was beneficial to regeneration of new alveolar bone and cement and establishment of new adhesion,and was regarded as a good substitute of old materials.