Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Proplast”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1989

[Experimental studies on augmentation of the mandibular region with proplast and lyophilized homogenous cartilage].

Proplast I, Proplast II and freeze-dried homogenous cartilage (1 x 2 x 5 mm) were implanted under and over the rabbit mandibular periosteum. Histological observations and contact microradiography (CMR) were performed to investigate the healing process in the surgical sites from 1 to 24 weeks after the operation. In addition, microangiography (MA) was carried out to investigate changes of vascularization in the groups in which Proplast implants were made. Results 1. Proplast implantation group 1) In the supraperiosteal placement group, CMR revealed no new bone formation around or inside the Proplast and no morphological changes of the host bone in contact with the Proplast. In the subperiosteal placement group, from the early postoperative stage, new bone formation occurred from the host bone beside the Proplast. New bone penetrated the Proplast from the new bone region and from the host bone in contact with the Proplast. In 6 months after the operation, Almost all Proplast pores were filled with new bone. From a comparatively early postoperative stage, resorption fossae appeared in the host bone surface. In addition, Haversian canals inside the host bone enlarged and the host bone cortex gradually grew thinner. No differences in new bone volume or host bone changes were noticed between the Proplast I and Proplast II groups. 2) In the supraperiosteal placement group, granulation tissue proliferation with slight round cell infiltration was observed around and inside the Proplast at an early stage. In 2 weeks after the operation, blood clots disappeared from the Proplast, in the center of which granulation tissue proliferated. Thereafter, granulation tissue was gradually transformed into fibrous tissue, although no new bone was observed in any region. Change almost never occurred in the host bone cortex, but slight swelling occurred in the periosteum in contact with the Proplast after 1 week. 3) In the subperiosteal placement group, swelling and slight round cell infiltration were observed in the periosteum covering the Proplast at an early postoperative stage. But, after 4 months, the periosteum had returned to normal condition. Beside and inside the Proplast, rapid granulation tissue proliferation and new bone formation were observed. New bone formation was observed beside the host bone, but not beside the periosteum. For a comparatively long time, resorbed fossae in the host bone surface and enlarged Haversian canals persisted. Host bone width gradually decreased.(ABSTRACT TRUNCATED AT 400 WORDS)

Alveolar Ridge Augmentation↗
PubMed1987

Orbital reconstruction with proplast.

Proplast was implanted in 15 cases of orbital reconstruction. Seven cases were orbital floor fractures, four cases were phthisical enophthalmos, and four cases were anophthalmic enophthalmos. In orbital floor fracture cases, thin (2-mm) Proplast was placed onto the fractured orbital floor after the incarcerated orbital tissue was released. To correct the enophthalmic socket, Proplast was shaped into small pieces (10 x 5 x 2 mm), then inserted into the subperiosteal space from all directions to fill up the orbital cavity. The results of these 15 cases were satisfactory. The average follow-up period is 13 months. The increased orbital volume seems less than the volume of the implanted Proplast; therefore, we suggest an 80-90% overcorrection rate in accordance with the computer measurements. In sum, Proplast serves as a very good material for orbital floor reconstruction and volume replacement.

Adolescent↗
PubMed1976

Proplast implants used in otology and in facial reconstructive surgery.

Proplast, a self-stabilising alloplastic material, was evaluated in ear surgery and in facial reconstructive surgery. Proplast implants were used on 33 patients to reconstruct the ossicular chain (total or partial ossicular replacement prosthesis), or to rebuild the mastoid cavity. The lack of extrusion over a 24-month period is encouraging. In facial reconstructive surgery 11 patients received Proplast implants to augment and restore facial contours. Contamination with saliva remains a problem, owing to the high porosity of Proplast, which could harbour infection. When Proplast was sterile when implanted, no extrusion appeared over a 12-month period. Although the patients presented here were followed up for a relatively short time, they provide reason for some optimism that the vexed question of alloplastics applied in the field of ear, nose and throat surgery may be solved.

Chin↗
PubMed1979

Characteristics of tissue growth into Proplast and porous polyethylene implants in bone.

(1) Bone does not form within internal pores of undistorted Proplast implants because of the small interconnecting pore size of the material; (2) the nonosseous, fibrous tissue which exists in the pores of Proplast implants in bone is not attached to the surrounding bone (i.e., Sharpey's fibers are not present). The load-bearing support which can be afforded by Proplast implants is limited by the incomplete bone ingrowth along the margins of the material and the tensile strength of Proplast.

Absorptiometry, Photon↗
PubMed1990

A staged laryngotracheal reconstruction using alloplast (Proplast) in the canine model.

Standard laryngotracheal reconstructive procedures are constrained by the availability of grafting materials and the ability to repair large defects. Reconstruction utilizing alloplasts may be ideal, but previous results have generally been poor. We present a two-stage procedure using Proplast to reconstruct large laryngotracheal defects in 6 dogs. A custom-made Proplast implant was inserted into a strap muscle pocket and buccal mucosa was placed in the adjacent peritracheal tissue. The muscle-Proplast composite graft was rotated to repair a large defect (3.25 cm by 2.25 cm). All 6 dogs survived. Endoscopic and histologic studies over 12 months showed continued stabilization and maturation of the implant. We feel that Proplast may be used as an alternative to autograft for reconstructing large laryngotracheal defects when the procedure is staged to allow maximal fibrous ingrowth and the implant is protected from infection.

Aluminum↗
PubMed1990

Facial augmentation with Proplast and nonporous hydroxylapatite in rhesus monkeys.

Using an extra-oral approach, subperiosteal pockets were created bilaterally over zygomatic and mandibular areas in six Rhesus monkeys. One side of each anatomic site received a Proplast I implant and the contralateral a nonporous hydroxylapatite (NPHA) block. Two animals were killed postoperatively at 3, 6, and 12 months, and the implants retrieved en bloc for histologic evaluation. Clinical evaluation showed the Proplast implants more stable than NPHA implants. Histologic evaluation for Proplast implants demonstrated complete encapsulation, fibrous tissue infiltration, fragmentation of implants, and some giant cell reaction. The NPHA implants were completely encapsulated with fibrous tissues, and no giant cell response, fragmentation, biodegradation, or bone formation was observed. We concluded that the Proplast was more stable than NPHA implants, but the NPHA produced less inflammatory cell and giant cell reaction.

Animals↗
PubMed1977

Proplast in the middle ear and oval window of cats.

Poly(tetrafluoroethylene) carbon fiber implant material (Proplast), an all-plastic material, was evaluated for use in otologic surgery. Response to the implant was studied in the middle ear and vestibule of 14 cats by placing the Proplast in the oval window after stapedectomy. After a one year follow-up, it appears that Proplast was tolerated well, causing no inflammatory reaction in either the vestibule or cochlea, or in the middle ear cavity. Fibrous tissue ingrowth was found throughout the implant, and a fibrous tissue membrane covered both the vestibular and the tympanic surfaces of the Proplast. Being well tolerated by both middle ear and inner ear tissues, this porous, all-plastic material offers several otologic applications.

Animals↗
PubMed1992

Multicenter evaluation of temporomandibular joint Proplast-Teflon disk implant.

Seven oral and maxillofacial surgeons from all U.S. American Association of Oral and Maxillofacial Surgeons districts participated in a retrospective study of Proplast II Teflon interpositional implants that were placed after meniscectomy in 680 TMJs (465 patients) and followed from 6 to 76 months. At longest follow-up a relatively high number (85.9%) 584 of 680 implants were in place with an average weighted follow-up of nearly 32 months. Of these 584 joints, a very high number, 540, (92.4%) were asymptomatic, however, 224 asymptomatic and 25 symptomatic joints with the implants in place exhibited some degree of condyle resorption that included 45 with malocclusion. In the worst case scenario, if condylar resorption is indicative of a worn Proplast II Teflon interpositional implant, then 364 (54%) of the 680 implants may fail. Failure rates per year range from Vitek's reported 3% to an average 18% clinician report in the literature. Higher rates are reported by individual clinicians, and our recent in vitro wear tests of Proplast II Teflon interpositional implants suggest an in vivo service life of only 3 years. Because no one has reported follow-up beyond 5 years, the long term performance and survival of any of these implants is doubtful. Asymptomatic patients should be evaluated yearly with tomography, CT, or MRI. Symptomatic patients should be evaluated every 4 to 6 months. Implant removal should be recommended if occlusal changes or condyle/fossa articular bone changes are active past the time of expected remodeling from surgery. This report summarizes the success/failure incidence from the literature and makes recommendations on follow-up, removal, and repair surgery.

Aluminum Oxide↗
PubMed1989

Zygomatic and mandibular augmentation with proplast and porous hydroxyapatite in rhesus monkeys.

Using an extraoral approach, subperiosteal pockets were created bilaterally over the zygomatic and mandibular regions in six Rhesus monkeys. One side of each animal received a Proplast I (Vitek Inc, Houston) implant and the contralateral side received an equivalent sized block of porous hydroxyapatite (HA). The animals were followed clinically and radiographically. Two animals were killed postoperatively at 3, 6, and 12 months, respectively. The implants were retrieved en bloc and halved. Half of each specimen was decalcified, embedded in paraffin, and stained. The other half was embedded in plastic, and sections were stained or carbon-coated for histometry scanning under electron microscopy. Clinical evaluation revealed that porous HA implants were more stable than Proplast implants. The Proplast implants showed complete encapsulation by infiltration with fibrovascular connective tissue, and progressive fragmentation with giant cell reactions. The porous HA implants were united to the underlying cortex by bony ingrowth. The volume of implants sampled within 2.5 mm of the underlying cortex contained 42.5% HA matrix and 23.8% bony ingrowth, and the surface area of the HA matrix (9.7 mm2/mm3) was 47.8% covered by bony ingrowth. No giant cell response, fragmentation, or biodegradation was observed or measured in the porous HA implants. The data from this primate model further substantiate previous canine studies and permit more reliable estimation of clinical performance. These results provide comparative data that can contribute to the decision-making process in selecting clinical implants.

Alveolar Ridge Augmentation↗
PubMed1988

Permanent Proplast temporomandibular joint implants: MR imaging of destructive complications.

We studied the radiologic and pathologic changes in 30 patients (34 joints) in which there were locally destructive bone and soft-tissue complications associated with previously inserted permanent temporomandibular joint (TMJ) Proplast-Teflon implants. The cases were selected as representative examples of patients with failed Proplast interpositional arthroplasty, in whom images of the TMJ were obtained with conventional radiography, tomography, and MR, and in whom both surgical and histologic findings were available. Clinical indications for imaging included joint pain, restricted joint motion, crepitus, preauricular swelling, regional lymphadenopathy, malocclusion either acquired or changed since implant surgery, and facial deformity. Surgery was then performed for the purposes of implant retrieval and joint debridement because of destructive soft-tissue and osseous changes observed from the imaging analysis in conjunction with significant clinical signs and symptoms. The pathologic changes, observed 4-54 months after implant surgery, included a destructive foreign-body-type granuloma and avascular necrosis of the mandibular condyle and condylar neck. Our findings suggest that MR is useful in the detection and evaluation of destructive complications that may accompany failed Proplast-Teflon implants in the TMJ. MR is superior to conventional radiography and tomography in detecting soft-tissue lesions and avascular necrosis of bone. Tomography more accurately delineates soft-tissue calcifications and cortical margins of osseous structures.

Adult↗
PubMed1977

The use of Proplast in experimental middle ear surgery.

The results of the use of Proplast, a new alloplastic material, in experimental middle ear surgery are described. This material was tested for cavity obliteration, closure of bony defects and as a columella between the tympanic membrane and the medial wall of the middle ear. Proplast was well tolerated in the middle ear cavity even in cases with inflammation of the middle ear. The implants were integrated within the recipient tissue by fibrous ingrowth occurring within one week. Bony ingrowth was observed in those cases where the implant contacted the bony wall within 3 weeks. Proplast which supported the tympanic membrane was infiltrated by fibrous tissue and incorporated in the lamina propria. No significant side effects were observed in a 6-month follow-up period although a possible influence on bone remodelling could not be fully excluded.

Animals↗
PubMed1977

Frontal sinus trauma: experimental reconstruction with proplast.

Trauma has become the most common pathologic entity requiring operative intervention in the frontal sinus. Treatment has evolved from simple open drainage to ablation with reconstruction at a later date. Methyl-methacrylate, currently the most widely used alloplastic material, has inherent disadvantages such as two-stage reconstruction, difficulty in handling and molding, and susceptibility to trauma. The present investigation evaluates Proplast, a biocompatible Teflon fluorocarbon polymer implant, in one and two-stage frontal reconstruction following traumatic defects to the canine frontal sinus. Following the loss of anterior or posterior frontal bone, Proplast provided excellent cosmetic reconstruction over a period of one year. Resistance to infection was good, reaction with dura and brain was absent, and cerebrospinal fluid leaks sealed rapidly. In contrast to other alloplastic materials, rapid vascularization and collagen ingrowth lead to stabilization rather than sequestration. Several advantages over alloplastic and metallic implants may give Proplast a unique potential in operative cranioplasty.

Animals↗
PubMed1989

Proplast as a pharyngeal wall implant to correct velopharyngeal insufficiency.

Proplast I was used as posterior pharyngeal wall implant to correct velopharyngeal insufficiency (VPI) in 26 patients. Specific criteria were followed in patient selection. Follow-up ranged from 4 months to 124 months. Postoperatively, 18 patients had elimination of VPI and three patients had minimal residual VPI. Four patients lost the implants secondary to infection with residual VPI. One patient had significant residual VPI without the loss of the implant. Based on long-term follow-up, no migration of the implant was seen and there was no detectable effect on subsequent facial growth. Predictably better results were achieved with younger patients in whom smaller implants were used. Conclusions from this study indicate that Proplast I is an acceptable pharyngeal wall implant material to correct VPI when the specific criteria are met and good surgical technique is used.

Adolescent↗
PubMed1979

Implants of Supramid, Proplast, Plasti-Pore, and Silastic.

Four types of synthetic materials were implanted in 54 rabbits: Supramid, Proplast, Plasti-Pore, and Silastic. Each material was implanted into the auricle and concomitantly into the subdermis of the face. Postoperative assessment was every one to three days, while killing was done at six weeks, six months, and one year postoperatively for microscopic evaluation. Supramid mesh contains black pigment, which became incorporated within the histiocytes and giant cells around the implanted mesh by six weeks; at one year, the soft tissues were pigmented microscopically. Proplast was not extruded despite an intense and persistent histiocytic and giant-cell reaction; its black color constituted a major drawback for implantation beneath thin skin. The Plasti-Pore used in these studies was rigid and somewhat difficult to sculpture, and it induced a persistent but minor cellular reaction. Silastic was easily displaced.

Animals↗
PubMed1979

A study of the reaction of human tissue to proplast.

The femoral stems of Thompson prostheses coated with a polytetrafluoroethylene/carbon fiber composite (proplast) were studied using conventional histological examination, scanning electron microscopy and electron probe microanalysis in "successful" firm implants and in a "loose" clinically unsuccessful implant. Ingrowth was found throughout the coatings of the successful prostheses. In the most firmly fixed prosthesis the ingrowth consisted of fibrous tissue with abundant giant cells; however, no bone ingrowth was detected. There was less composite pore infilling in the unsuccessful implant. From both clinical, radiological and the studies described above, it is concluded that fibrous tissue ingrowth was a secondary stabilizing phenomenon in the proplast-coated prostheses studied.

Aged↗
PubMed1976

Proplast chin augmentation.

A method of chin augmentation employing a newer synthetic material (Proplast) is presented. The characteristics and biocompatibility of Proplast are detailed. Technical considerations and results of short term clinical trials in 20 patients are discussed. One implant necessitated removal secondary to trauma four months after surgery. All other implants including over 30 additional cases have been without incident.

Biocompatible Materials↗
PubMed1977

A comparison of the stability of proplast-coated and cemented Thompson prostheses in the treatment of subcapital femoral fractures.

Twenty randomly selected patients with displaced subcapital fractures of the femur, were treated with prosthetic replacement of the femoral head using a Thompson prosthesis of which the intramedullary portion was coated with Proplast. The results were compared with a control group of 20 similar patients in whom the standard Thompson prosthesis was used with acrylic cement. At follow-up, which ranged from 3 to 17 months, there was substantial X-ray evidence of prosthetic loosening in the Proplast series.

Bone Cements↗
PubMed1977

Proplast-coated high-strength magnets as potential denture stabilization devices.

This study was designed to determine if a samarium-cobalt magnet could be effectively sealed from the in vivo environment and be physically stablized in bone under similated functional stress. The following conclusions can be made from this study. (1) It is possible to effectively seal a samarium-cobalt magnet from the in vivo environment. Clinical observation, radiographs, and photomicrographs on all samples showed good healing and dense tissue over the surgical sites. The samples showed that connective tissue penetrated the Proplast, and clinically, the magnets appeared to be well stabilized in bone. (2) It follows that if magnets are properly coated and good surgical techniques are used, Proplast can be an effective sealant. Samarium or cobalt appeared in the surrounding tissues only where the coating was faulty. Further studies are being conducted which will cover a 2 year period as opposed to the original 5 month study. It is hoped that with specific tests, we will be able to demonstrate absolute fixation and no migration of the magnets.

Animals↗