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Objectives To systematically present and interpret the current literature on research and treatment perspectives for mandibular osteoradionecrosis (mORN) in the field of biomaterials. Material and methods A systematic review of the literature using the “Synthesis without meta-analysis” (SWiM) methodology was performed on PubMed, Embase and Cochrane, focusing on the implantation of synthetic biomaterials for bone reconstruction in mORN in humans and/or animal models. The primary endpoints were the composition, efficacy on mORN and tolerance of the implanted synthetic biomaterials. Results Forty-seven references were obtained and evaluated in full-text by two assessors. Ten (8 in humans and 2 in animal models) met the eligibility criteria and were included for analysis. Materials most often comprised support plates or metal mesh (5 of 10 cases) in combination with grafts or synthetic materials (phosphocalcic ceramics, glutaraldehyde). Other ceramic/polymer composites were also implanted. In half of the selected reports, active compounds (molecules, growth factors, lysates) and/or cells were associated with the reconstruction material. The number of articles referring to implantation of biomaterials for the treatment of mORN was small, and the properties of the implanted biomaterials were generally poorly described, thus limiting a thorough understanding of their role. Conclusion In preventing the morbidity associated with some reconstructive surgeries, basic research has benefitted from recent advances in tissue engineering and biomaterials to repair limited bone loss.

Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide-ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first-line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra-anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: "malignant ureteral obstruction," "tandem ureteral stents," "metallic ureteral stents," "resonance stent," "metal mesh ureteral stents" and "extra-anatomic stents." The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head-to-head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case-by-case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence-based medicine and guidelines for patients with malignant ureteral obstruction.

Airway foreign bodies are a medical emergency in children, as airway obstruction results in immediate respiratory distress. Common ingested foreign bodies differ among children from different social backgrounds, and metal foreign bodies, such as pins, coins, and dental appliances, are widely reported. Herein, we present the first case of a broken metal mesh foreign body ingested by an infant. An 11-month-old boy was found to be licking and biting the mesh cover of an electric lint remover. Part of the broken mesh was found in his mouth, but his mother could not remove it. The patient was referred to our hospital that same day. Although flexible laryngoscopy revealed no foreign bodies in the upper airway, computed tomography scan revealed high density foreign bodies in the left oropharynx. Two pieces of metal mesh that were buried in the left tonsillar fossa were removed under general anesthesia. The patient recovered uneventfully and was discharged the following day. This case suggests that thin metal mesh may be broken by infants with erupting deciduous teeth and become a pharyngeal foreign body.

An electromagnetic pulse (EMP) with high energy can damage electronic equipment instantly within a wide range of thousands of kilometers. Generally, a metal plate placed inside a thick concrete wall is used against an EMP, but it is not suitable for an EMP shielding window, which requires not only strong shielding effectiveness (SE) but also optical transparency (OT). In this paper, we propose a very thin and optically transparent structure with excellent SE for EMP shielding window application. The proposed structure consists of a saltwater layer held between two glass substrates and two metal mesh layers on the outside of the glass, with a total thickness of less than 1.5 cm. The SE and OT of the structure are above 80 dB and 45%, respectively, which not only meet the requirement of EMP shielding for military purposes but also retain the procedure of good observation. Moreover, the OT of the structure can be significantly improved using only one metal mesh film (MMF) layer, while the SE is still maintained high to satisfy the required SE for home applicants. With the major advantages of low cost, optical transparency, strong SE, and flexible performance, the proposed structure can be considered a good solution for transparent EMP shielding windows.

Revision total hip arthroplasty in the setting of acetabular bone loss is a challenging procedure and requires a solid understanding of current acetabular reconstruction options. Despite major developments in the field of revision hip surgery in recent decades, reconstruction of acetabular defects remains a major problem in order to achieve primary stability and durable fixation without sacrificing additional bone stock. Although there are several ways to classify acetabular bone defects, the Paprosky classification system is the most commonly used to describe the defects and guide treatment strategy. An understanding of the bone defects associated with detailed pre-operative assessment and planning are essential elements in order to achieve satisfactory outcomes. Multiple acetabular reconstructive options are currently available including impaction bone grafting with metal mesh, reinforcement rings and antiprotrusio cage, structural allografts, cementless hemispherical cups, extra-large “jumbo cups”, oblong cups, modular porous metal augments, cup-cage constructs, custom- made triflange cups, and acetabular distraction. To date, debate continues as to which technique is most effective due to the lack of long-term studies of modern reconstruction systems. Further long-term studies are necessary to assess the longevity of the different implants. The purpose of this study was to review the current literature and provide a comprehensive understanding of the available reconstruction options with their clinical outcomes.

Objective: To review the literature on the effectiveness, safety and long-term patency of ureteric metal mesh stents (MSs), as a variety of MSs have been used for managing malignant ureteric obstruction over the last three decades. Materials and methods: A systematic review using the search string; Ureterâ AND (stent OR endoprosthesis) AND metalâ was conducted on PubMed, Scopus, Web of science and Cochrane Library online databases in May 2016. Prospective, retrospective, and comparative studies including MSs were included. The primary endpoint was the patency rate and the secondary endpoint was complications. Results: In all, 324 publications were screened and 31 articles were included in the systematic review; 21 prospective and 10 retrospective studies. These studies reported the effectiveness of specific MSs in population studies, in comparative studies among different MSs, as well as among MSs and JJ stents. It should be noted that all comparative studies were retrospective. Conclusion: The experiences with vascular MSs, such as the Wallstent⢠(Boston Scientific/Microvasive, Natick, MA, USA), were related to high occlusion rates, due to endoluminal hyperplasia, and long-term disappointing patency. The use of covered MSs designed for the vascular system was also unfavourable. The Memokath 051⢠(PNN Medical A/S, Kvistgaard, Denmark) had better patency rates, but also higher migration rates. The long-term results were acceptable and rendered the Memokath 051 as a viable option for the management of malignant ureteric obstruction. The Uventa⢠(Taewoong Medical, Seoul, Korea) and Allium⢠(Allium Medical Solutions Ltd, Caesarea, Israel) MSs, specifically designed for ureteric placement, provided promising results. Nevertheless, the wide acceptance of these MSs would require well-designed clinical studies and long-term follow-up. Keywords: Stent, Metal stent, Ureteric obstruction, Malignant

Flooring is an important component of indoor housing systems for livestock as it can impact animal hygiene and welfare. Therefore, the aim of this study was to evaluate the lying and elimination preferences of goats, as well as their relative udder cleanliness, when presented with four different flooring types. At 8 months of age, 32 non-lactating female Saanen cross does (45.4 ± 6.10 kg) were restricted to one of four different flooring types for 10 days (2.9 m2/goat), then restricted to the other three surfaces (10 days per surface) using a Latin square design (n = 8 replicates, 4 goats/replicate). The four flooring types included wood shavings (WS), metal mesh (MM), plastic slats (PS) and rubber matting (RM). After the restriction period, goats were given free access to all four flooring types simultaneously for 48 h. Lying behaviour was recorded using accelerometers. In addition, lying location and elimination (urination and defecation) behaviour were recorded from video for 24 h at the end of the free access period. To assess cleanliness, Escherichia coli (E. coli) counts were measured on the udder region of the goats and on each flooring type at the beginning of each restriction period. During the restriction period there was no difference in the time goats spent lying on any of the four flooring surfaces; however, goats on WS performed more lying bouts (P ≤ 0.005) of shorter duration (P ≤ 0.005) compared to goats on RM during day 2, 3, 4 and 5. During the free access period, goats spent more time on RM and PS and less time on MM and WS (% observations/24 h: RM: 46.3, PS: 30.4, MM: 11.6, WS: 11.5, SED: 6.19, P

The paper presents a new method of ergonomic evaluation of gloves protecting against cuts and stabs during knife use, consisting of five manual dexterity tests. Two of them were selected based on the available literature and relevant safety standards, and three were developed by the authors. All of the tests were designed to simulate occupational tasks associated with meat processing as performed by the gloved hand in actual workplaces. The tests involved the three most common types of protective gloves (knitted gloves made of a coverspun yarn, metal mesh gloves, and metal mesh gloves with an ergonomic polyurethane tightener) and were conducted on a group of 20 males. The loading on the muscles of the upper limb (adductor pollicis, flexor carpi ulnaris, flexor carpi radialis, and biceps brachii) was measured using surface electromyography. For the obtained muscle activity values, correlations were found between the glove type and loading of the upper limb. ANOVA showed that the activity of all muscles differed significantly between the five tests. A relationship between glove types and electromyographic results was confirmed at a significance level of α = 0.05.

Ureteral obstruction represents a heterogeneous disease pattern and is treated by ureteral stenting or percutaneous nephrostomy (PCN) depending on the necessity. The benefits of urinary diversion with ureteral stenting or PCN in malignant ureteral obstruction (MUO) for patient survival are only moderate. No differences have been found between ureteral stenting and PCN in MUO with regard to median patient survival and complication rates. In cases of MUO there is currently no evidence that urinary diversion improves the quality of life. Alternative concepts of ureteral stenting, such as tandem ureteral stents, metallic ureteral stents or metal mesh ureteral stents have not yet shown clear benefits. In benign ureteral obstruction, prospective randomized studies have demonstrated comparable quality of life after PCN or ureteral stenting. The method of choice for urinary diversion is influenced by the recommendations, personal experience of the clinician and the availability of the method.

Metal mesh foil bearings (MMFBs) are novel gas foil bearings with lower manufacturing costs and higher inherent material energy dissipation ability than traditional bump-type foil bearings. To improve the design guidelines of MMFBs and predict bearing performance, a compact theoretical model is presented by considering the metal mesh substructure as assembled springs and dry friction joints. The proposed analytical model considers the effects of several factors such as relative density, wire diameter, geometrical size, and radial interference of the metal mesh substructure. The predicted stiffness coefficients, which take the dry friction effect into account, show strong nonlinear characteristics with the increasing displacement and have a significant difference between the loading and unloading process. A series of static load tests are conducted to verify the theoretical model of MMFBs. The hysteresis loops of static load versus bearing deflection with respect to the different relative densities...

The application of flexure pivot tilting pad gas bearings (FPTPGBs) with metal mesh dampers (MMDs) in parallel in high-performance oil-free turbomachineries has been considered because of their high effective damping level and adequate compliance to the variations in rotor geometry. This study proposes a comprehensive theoretical model of these bearings by coupling the FPTPGB model and MMD model. The effects of many parameters, including damper mesh density, pad radial stiffness, MMD radial interference, bearing nominal clearance and pad preload, are discussed. Results show that the direct damping coefficients of the bearings in this study are higher than those of FPTPGBs.

The stability of oil-free high-speed turbo-machinery can be effectively improved by increasing the damping characteristic of the gas foil bearing (GFB). Novel hybrid bump-metal mesh foil bearings (HB-MFBs) have been previously developed. Prior experimental results show that the parallel combination of bump structure and metal mesh not only can improve the structure stiffness but also provide better damping property compared with the bump-type foil structure. To investigate the dynamic behavior of floating HB-MFBs and promote its application, this study measured the dynamic force coefficients of HB-MFBs on a rotating test rig. The vibrations of HB-MFBs with different mesh densities (40%, 32.5%, and 25%) and a generation І bump-type foil bearing (BFB) with similar size are measured under static and impact loads to estimate the bearing characteristics. Static load test results show that the linear stiffness decreases when the air film is generated (from 0 rpm to 20 krpm) but increases gradually with speed (from 20 krpm to 30 krpm, and 40 krpm). Moreover, the dynamic force coefficients of HB-MFBs indicate the significant influence of metal mesh density on bearing dynamic characteristics. The growth in block density increases the dynamic stiffness and damping coefficients of bearing. The comparison of HB-MFB (32.5% and 40%) and BFB emphasizes the good damping characteristics of HB-MFB.

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.

Mandibular implant-retained overdentures have become the standard of care for patients with mandibular complete edentulism. As part of the treatment, the mandibular implant-retained overdenture may require a metal mesh framework to be incorporated to strengthen the denture and avoid fracture of the prosthesis. Integrating the metal mesh framework as part of the acrylic record base and wax occlusion rim before the jaw relation procedure will avoid the distortion of the record base and will minimize the chances of processing errors. A simplified method to incorporate the mesh into the record base and occlusion rim is presented in this technique article.

Loss of an organ such as a finger not only imposes a functional impairment, but also leads to unaesthetic appearance and a deep psychological stigma to the patient. Hence replacement of such missing finger with the help of an artificial finger prosthesis has been very successful. The success of the prosthesis depends on the precision in meticulous planning and designing of prosthesis, technique of fabrication and the materials used. This article describes fabrication of a finger prosthesis by a modified technique, by making a metal conformer with a wire mesh. This design offers maximum retention and excellent aesthetics, thereby imparting a lifelike appearance to the hand with missing finger.

This study mainly analyzed the factors that affected the mechanical properties of laminated veneer lumber（LVL）. To increase the mechanical properties, metal mesh was inserted into LVL that made of fast-growing timber. Effects of different factors were evaluated on the mechanical properties of LVL, several enhancement modes of metal mesh were designed to reinforce the LVL. Then, the mechanical properties (modulus of rupture and modulus of elasticity) of the LVL specimens were measured by static bending test. The results of different enhancement modes were analyzed and compared to investigate the effects of different factors. The position of metal mesh and the mesh number of metal mesh make significant effects on the MOE; the type of metal mesh and the angle of metal mesh-wood grain do not have any obvious effects on the MOE. The type of metal mesh and the position of metal mesh make significant effects on the MOR; the mesh number of metal mesh and the angle of metal mesh-wood grain do not have any obvious effects on the MOR.

Five patients presented with fiber metal mesh shedding of a Harris Galante II acetabular cup detected between 11 and 15 years after implantation. All patients presented with hip pain and 4 demonstrated gross acetabular loosening and fiber metal separation on preoperative radiographs. The remaining patient underwent revision surgery because of a liner dislodgment and had a radiographically well fixed shell. Loosening and fiber metal separation were detected intraoperatively. Scanning electron microscopy of the retrieved shells demonstrated isolated diffusion bonding marks in the areas where the mesh separated from the substrate and no evidence of corrosion. Progressive osteolysis in the iliac bone was evident in 4 of our cases. Progressive iliac osteolysis may lead to loss of bone support in well-fixed cups and excessive stresses transferred to the interface between the fiber metal mesh and the titanium substrate leading to the separation of the 2 layers. Fiber metal separation may contribute to long-term loosening in the Harris Galante acetabular component.

Rotors supported by gas foil bearings (GFBs) experience stability problem caused by subsynchronous vibrations. To obtain a GFB with satisfactory damping characteristics, this study presented a novel hybrid bump-metal mesh foil bearing (HB-MMFB) that consists of a bump foil and metal mesh blocks in an underlying supporting structure, which takes advantage of both bump-type foil bearings (BFBs) and MMFBs. A test rig with a nonrotating shaft was designed to estimate structure characterization. Results from the static load tests show that the proposed HB-MFBs exhibit an excellent damping level compared with the BFBs with a similar size because of the countless microslips in the metal mesh blocks. In the dynamic load tests, the HB-MFB with a metal mesh density of 36% presents a viscous damping coefficient that is approximately twice that of the test BFB. The dynamics structural coefficients of HB-MFBs, including structural stiffness, equivalent viscous damping, and structural loss factor, are all dependent on excitation frequency and motion amplitude. Moreover, they exhibit an obvious decrease with the decline in metal mesh density.

Hypothermic fatalities in humans are characterized by a range of often subtle pathological findings that typically include superficial erosive gastritis (Wischnewski spots). Experimental studies have been successfully performed using animal models to replicate this finding, however study animals have inevitably been subjected to a variety of additional stressors including food deprivation, restraint and partial immersion in water while conscious. As it is recognised that stress on its own may cause superficial erosive gastritis, a model has been developed to enable the study of the effects of hypothermia in isolation. 42 Sprague-Dawley rats were allowed free social contact and were fed and watered ad libitum prior to being anaesthetized with isoflurane. Once unconscious, rats were placed on drape cloth covering metal mesh platforms in a styrofoam box packed with ice. The apparatus enabled both maintenance of a specific low temperature (26 °C) in 14 animals, and continued reduction of core temperatures in the remaining 28 (who all died of hypothermia under anaesthesia). Examination of the gastric mucosa in both groups macroscopically and microscopically failed to demonstrate typical Wischnewski spots in any of the 42 animals. Thus, in this model, death from hypothermia occurred without the development of these lesions. These results suggest that stress may be a significant effect modifier in the development of Wischnewski spots in lethal hypothermia.

Reconstruction of the failed acetabular component in total hip arthroplasty (THA) can be challenging. Although there are multiple reconstructive options available, a cementless acetabular component inserted with screws has been shown to have good intermediate-term results and is the reconstructive method of choice for the majority of acetabular revisions. We reviewed the results of 138 consecutive acetabular revisions done with a hemispheric, cementless acetabular component that is sintered with Ti fiber metal mesh and was inserted with line-to-line reaming and multiple screws for fixation. At a mean of 15 years, 19 acetabular components had been revised (13.8%); seven were revised for recurrent instability, six were revised for deep periprosthetic infection, five well-fixed cups were removed at the time of femoral revision, and one cup was fixed by fibrous tissue only at the time of femoral revision and was removed. One acetabular component was radiographically loose. Survivorship of the component was 81% at 15 years when revision for any reason was considered as an end point and 96% when revision for loosening or radiographic evidence of loosening was considered as a second end point. Cementless acetabular revision provides durable results at 15 years with a low rate of failure for loosening.

Drug eluting stents (DES) proved to minimize neointimal hyperplasia in coronary vessels. Hyperplastic reaction is the most common unwelcome event related to the use of metal mesh stents in the ureter. We evaluated the effect of zotarolimus eluting stent (ZES- Endeavor Resolute, Medtronics Inc, USA) in porcine and rabbit ureter. Methods: A ZES and a bare metal stent (BMS) were inserted in each ureter of 10 pigs and 6 rabbits. The insertion was performed by retrograde approach. Computerized tomography (CT) was used for the evaluation of porcine ureters while intraoperative intravenous pyelography (IVP) for rabbit ureters. The follow-up included CT or IVP every week for the following 4 weeks for pigs and 8 weeks for rabbits. Renal scintigraphies were performed prior to stent insertion and during the 3rd week in all animals. Optical coherence tomography (OCT) has been used for the evaluation of the luminal and intraluminal condition of the stented ureters. Histopathologic examination of the stented ureters embedded in glycol-methacrylate was performed. Results: Hyperplastic reaction was present in both stent types. BMSs in 7 porcine ureters were completely obstructed while porcine ureters stented with ZES had hyperplastic tissue which did not result in obstruction. Two rabbit ureters stented by BMS were occluded while no ZES was associated with ureteral obstruction. The function of the 7 porcine renal units and the two rabbit units with obstructed stented ureter was compromised. The OCT revealed increased hyperplastic reaction in the ureters stented by BMSs in comparison to ZESs. Although, hyperplastic reaction was present in all cases, pathology examination revealed significantly more hyperplastic reaction in BMSs. Conclusion: ZESs in the pig and rabbit ureter were not related to hyperplastic reaction resulting in stent occlusion. These stents were related to significantly lower hyperplastic reaction in comparison to BMSs while inflammation rates were similar for both stent types.

As an alternative to commercially available porous beads and fiber metal mesh, a new porous coating, orderly oriented wire mesh (OOWM), was developed. Rectangular plugs, 10×5×5 mm with porous-coated beads, and four different OOWM configurations were inserted into bilateral femoral condyles of adult beagles. Dogs were sacrificed immediately after implantation, and at 4 weeks, 8 weeks, and 12 weeks postimplantation. Mechanical pullout strength of plugs revealed that porous beads are equivalent to the simplest OOWM at 12 weeks postimplantation. Of the four OOWMs tested, the 257×25 single layer was significantly more stable than others at 4 weeks postimplantation. These results indicate that in an in vivo unloaded model, OOWM is just as effective as the porous beads in achieving early bone ingrowth and stability.

To compare, in vitro, probe velocity/displacement, retropulsion, and fragmentation capacity of the cordless electromechanical (LithoBreaker) (hard vs soft probe guide) and pneumatic (StoneBreaker).Probe velocities/displacements were measured using high-speed resolution camera (100.000 frames/s). The lithotripsy probes were projected through a 7.5F ureteroscope against a nonfrangible led ball placed in a 15F horizontally mounted silicone tube immersed in water bath as an in vitro ureter model. Retropulsion is considered as displacement distance of led ball. Fragmentation efficiency was quantified as number of shots required to break Bego-stone phantoms (hard [15:3] and soft [15:6], average size 7.5 × 5.5 mm) placed on metal mesh into3-mm fragments. Mean and standard deviation of repetitive measurements were statistically analyzed.StoneBreaker yielded higher probe velocity (22 ± 1.9 m/s) compared with LithoBreaker with hard (14.2 ± 0.5 m/s) and soft (11.5 ± 0.5 m/s) probe. Maximum probe displacement for StoneBreaker was 1.04 mm vs 0.9 mm and 1.1 mm (hard vs soft LithoBreaker-probe, respectively). Retropulsion using 1-mm probes showed no statistical differences. Using harder 2-mm probe decreased Lithobreaker retropulsion significantly compared with Stonebreaker. The amount of shots (1-mm probe) to fragment soft Bego stones was significantly higher for LithoBreaker with soft (mean 31.5 ± 11.31) and hard (mean 21.5 ± 5.29) probe guide vs StoneBreaker (mean 11.2 ± 2.65). Fragmentation efficiency for hard Bego stones showed similar statistically significant outcome. Comparison of the 2 probe guides showed higher velocity linked to harder-probe that improved LithoBreaker fragmentation performance and reduce propulsion.Both examined lithotripters are effective in cracking stone phantoms with relatively low pulse number. They produce comparable retropulsions. Fragmentation improved substantially using LithoBreaker with hard probe guide. More tests are required to assess differences in stone clearance time.

Revision total hip arthroplasty in cases with severe acetabular bone loss is challenging. In the presence of combined cavitary and segmental defects without superior acetabular coverage, reconstructions with a structural acetabular allograft protected by a cage or a custom-made triflange cage have been the treatment of choice. The current paper describes an impaction grafting into a mesh for uncontained defects in revision total hip arthroplasty.After restoring containment with a mesh fixed with small fragment screws, defects were restored using impaction grafting combined with a cemented all-polyethylene cup.Fourteen consecutive acetabular impaction graftings were performed by two surgeons. All patients had a type 3B defect according to the Paprosky classification.No re-revisions or radiographic failure was detected in the early follow-up period.Impaction grafting into a mesh is an interesting treatment option to restore bone in combined cavitary and segmental defects.

There are occasions where it is desired to increase the bond strengths of no-mix adhesives. Noncompliant patients and hypocalcified and fluorosed tooth enamel require higher bond strengths than usually obtained. It was the purpose of this investigation to study the effects of adhesion promoters to increase bond strengths. In vitro shear bond strengths that use the Instron machine (Instron Corp., Canton, Mass.) and thermocycling methods indicate the bond strengths of a no-mix adhesive bonding 80 gauge metal mesh brackets can be significantly improved through the following techniques: control (MPa 9.0), sandblasting (MPa 10.8), sandblasting and silanating (MPa 11.9), Rocatec system (MPa 10.8), Kulzer “silicoating” (MPa 13.2), and adhesion promoters—Megabond—(MPa 13.3). These adhesive promoters have been and are clinically being tested with promising results. (A M J O RTHOD D ENTOFAC O RTHOP 1995;108:237-41.)

Simple esophageal strictures, which are focal, straight, and large in diameter, usually require 1 - 3 dilation sessions to relieve symptoms. However, complex strictures, which are long, tortuous, or associated with a severely compromised luminal diameter, are usually more difficult to treat with conventional bougie or balloon dilation techniques, and often have high recurrence rates. Although the permanent placement of self-expandable metal stents (SEMS) has been used to manage refractory benign esophageal strictures, this procedure is associated with additional problems, such as stricture from tissue hyperplasia, stent migration, and fistula formation. Thus, several new types of stents have been developed, including temporary SEMS, self-expandable plastic stents (SEPS), and biodegradable stents. The use of these new products has produced varied results. Temporary SEMS that have been used to relieve benign esophageal conditions have caused granulation tissue at both ends of the stent because of contact between the mucosa and the exposed metal components of the stent, thus hindering stent removal. We examined the tissue response to two new types of SEMS, a flange-type and a straighttype, each coated with a silicone membrane on the outside of the metal mesh. These two SEMS were evaluated individually and compared with a conventional control stent in animal experiments. Although the newly designed stents resulted in reduced tissue hyperplasia, and were thus more easily separated from the esophageal tissue, some degree of tissue hyperplasia did occur. We suggest that newly designed DES (drug-eluting stents) may provide an alternative tool to manage refractory benign esophageal stricture.

Covered self-expandable metal stents were developed to overcome tumor in-growth through the metal mesh. Stent migration is one of their malfunctions. Recently, the partially covered wallflex stent (PCWS) was developed with flared ends to prevent migration However, difficulty has been reported in its removal. We describe the removal of a PCWS embedded in mucosal hyperplasia at the uncovered proximal flared end, visualized by using SpyGlass cholangioscopy.

Advances in stent design have led to a substantial increase in the use of stents for a variety of malignant and benign strictures in the gastrointestinal tract and biliary system. Whereas early stents were mostly composed of plastic, the majority of contemporary stents are self-expanding metal stents that are composed of either nitinol or stainless steel. These stents are able to exert an adequate expansile force and, at the same time, are highly flexible and biocompatible. Covered stents have been introduced to minimize tumor ingrowth through the metal mesh but are associated with higher rates for spontaneous migration. This has led to the development of covered stents with uncovered ends and stents with both covered and uncovered layers. Drug-eluting and biodegradable stents are also likely to become available in the near future. Although stents appear to be the preferred form of palliation for some patients with advanced cancer, many patients will benefit from a multidisciplinary approach that usually includes surgeons and oncologists.

Endoscopic stent placement is a well established treatment for biliary obstruction. The known disadvantage of plastic stents is their tendency to clog. This article describes another approach to treating biliary obstruction secondary to malignant neoplasms using the expandable metallic Wallstent endoprosthesis.

In this paper we will present the automated inspection of stent manufacturing, which we developed and applied to acquire, process and analysis the image data of the stent using a line scan camera and automated multi axes scan mechanics. A stent is a wire metal mesh tube used to prop open an artery during angioplasty.

In this paper, the flexural properties of glass fiber reinforced polymer composites with metal mesh layers were investigated. Two thermoplastic polymers, polyetherimide (PEI) and polyphenylene sulfide (PPS) were used as the matrix. Stainless steel was chosen as the mesh material due to its excellent strength and stiffness properties. The position of the metal mesh within the laminate stack was varied and the effect on the flexural properties and damage mechanisms was compared to that of the plain laminate. Placement of the mesh in the middle of the laminate led to the greatest improvement in flexural properties for the PEI laminates with an increase in specific flexural stress and strain of over 11% in both cases. However, the same case was not found for the PPS laminates and this was attributed to the poor adhesion between the PPS and the metal mesh.

Endoscopic clearance of large or impacted stones in the main pancreatic duct (MPD) remains a clinical challenge. In this study, we attempted to technically modify the metallic stent to facilitate the clearance of large pancreatic stones in 4 patients, hoping to lower the operative risks and shorten hospital stay.Four patients with chronic pancreatitis and large stones in the MPD received endoscopic treatment. Inclusion criteria were: (1) pancreatic intraductal stones (number3; diameteror=10 mm) and strictures identified in the distal MPD; (2) calculi mainly located in the head, neck and/or body of the pancreas, and (3) failed clearance of stones using a balloon catheter or Dormia basket. Before clearing the pancreatic calculi completely, a technically modified uncovered self-expandable metallic pancreatic stent was implanted in the MPD for 4-7 days to dilate the ductal stenosis, and then drawn out through the working channel.As the MPD had been sufficiently expanded by the stent, the calculi were removed completely and uneventfully by the balloon or Dormia basket in all 4 patients, without inducing major postoperative complications. A 9- to 15-month follow-up did not find major complications or recurrence of large calculi in the MPD.Technically modified metallic stenting is a minimally invasive and clinically feasible alternative to extracorporeal shock wave lithotripsy in the management of large pancreatic duct stones.

Reconstructing large loaded bone defects with ceramic bone graft extenders is tempting considering the expected future donor bone shortage. However, whether there are negative effects is unknown. Standardized large defects in the acetabulum of goats were created and subsequently reconstructed with metal mesh and impacted morselized cancellous bone grafts or a 50/50% volume mixture of tricalcium phosphate-hydroxyapatite granules and morselized cancellous bone grafts using the bone impaction grafting technique. Subsequently, a cemented total hip prosthesis was inserted. Clinically, no differences were observed between groups. Most of the morselized cancellous bone graft had been resorbed and incorporated into new bone after 15 weeks. The large tricalcium phosphate-hydroxyapatite granules were integrated, the smaller crushed tricalcium phosphate-hydroxyapatite granules were surrounded by osteoclasts or engulfed by macrophages and giant cells. The cement penetration into the reconstructive layer and the quality of the bone based on a semiquantitative score were similar in both groups. We found no suggestion of tricalcium-hydroxyapatite granule-induced third-body wear in this short-term followup study. No negative effects were observed in this study, and therefore, it seems reasonable to use tricalcium-hydroxyapatite granules in a 50/50% volume mix with morselized cancellous bone graft as a bone graft extender in acetabular revision surgery with the bone impaction grafting technique.

Background: Symptomatic common bile duct strictures are frequently seen in the course of severe chronic pancreatitis with a reported incidence of 10-30%. The exact role of endoscopic stenting with metal prostheses as definitive treatment has not yet been clearly defined. Methods: Six patients with symptomatic distal common bile duct stricture in the setting of chronic pancreatitis were treated with a self-expandable metal stent in an attempt to achieve permanent drainage. All cases were approached non-operatively and underwent prior unsuccessful treatment with plastic prostheses. Results: The patients received a self-expandable metal Wallstent® after a median follow-up of 14 months of plastic stenting. The median follow-up time was 58 months and the stents remained open for a median time of 20 months, respectively. Overall, in 2 of 6 cases the metal stent therapy was successful while 4 of 6 patients required additional endoscopic procedures. Conclusions: Self-expandable metal stents could be useful and adequate in patients who suffer from symptomatic obstructive jaundice due to chronic pancreatitis. However, they provide acceptable dilation of the common bile duct for only a limited period of time. Overall, endoscopic stenting with self-expandable metal stents seems to be an advantageous treatment only for a subgroup of patients who are unfavorable candidates for surgical drainage. To clarify the role of the endoscopic approach, prospective trials with homogenous and larger patient numbers are necessarily in the future.

Long-segment ureteral obstruction by hormone-refractory carcinoma of the prostate is a difficult problem to manage. J-Stents often obstruct by compression. Metal mesh stents have been used successfully in the management of extrinsic ureteral obstruction caused by malignant disease. In this paper, we review our results in three patients in terms of the defined objective of palliation.All three patients presented with painful obstructed kidneys and renal failure from long (7-10-cm) distal ureteral strictures responding to nephrostomy drainage. Endoluminal metal mesh stents of 7 to 8-mm diameter of various lengths (depending on the size of the stricture) were implanted after antegrade balloon dilatation of the stricture by a standard technique. The case notes were reviewed for technical success, preservation of the renal units, complications, and the impact on the overall quality of life.All three stents were placed without any complication and showed patency on contrast study. In one patient, the stent obstructed after 5 months, necessitating placement of a nephrostomy tube. In the remaining two patients, the stents obstructed within 3 months. During these 3 months, both patients had multiple admissions for stent-related complications and other symptoms of their disease. Overall quality of life was poor for these patients.Metal mesh ureteral stents give poor palliation in distal strictures caused by hormone-refractory carcinoma of the prostate. Permanent nephrostomy may be a more acceptable alternative in these patients with short life expectancies.

Re-establishment of the oesophageal lumen is the main focus of care in patients with inoperable oesophageal carcinomas. The self-expanding metal mesh stents (MMS) are increasingly being used. 51 patients aged 44 - 89 with inoperable oesophago-gastric carcinomas were intubated with MMS. 18 of these patients had endoscopic laser therapy (ELT) as primary palliation. 25 patients required follow-up endoscopy at variable intervals after stent insertion. 17 patients were found to have significant tumor growth (9), overgrowth (4) and both (4). All these patients were treated with Nd:YAG or diode laser for maintenance of satisfactory swallowing. 4 patients being treated with Nd:YAG laser developed deformity of MMS. This complication was not encountered with diode laser. The reblockage of MMS due to ingrowth or overgrowth of tumor is a not uncommon complication. The timing of the stent insertion should be carefully chosen since the longer the stent is in situ, the greater is the likelihood of tumor ingrowth or overgrowth. ELT can effectively deal with tumor ingrowth and overgrowth. Nd:YAG laser can cause melting of MMS. Overall the combination of ELT and MMS may offer the best palliation, particularly when patient survival of several months is anticipated.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this study, the test results of commercialized 2 ton cargo truck on road for 6 months, are reported using the soot removal equipment at low voltage and with a short regeneration time. The equipment consists of using commercial truck battery, changing electrically neutral soot to negative charged soot. It adsorbs charged soot electrically with the metal mesh connected to positive pole and washes the soot with liquid detergent, during the cutting off of electric source. The removal of the accumulated soot was completed within two minutes, with 100% regeneration.

A nonsurgical method of female sterilization was investigated in rabbits.A self-expanding microspindle (length 9-18 mm, diameter 1.5-2.0 mm) made from tubular metal mesh was implanted in a single fallopian tube of 12 rabbits via catheterization of a single uterus. The contralateral fallopian tube and uterus served as controls. Each rabbit was scheduled to undergo three cycles of breeding. Before delivery, absence of pregnancy on the side with the microspindle was verified with hysterography.Eight rabbits completed three cycles of breeding and pregnancy. Two rabbits had one pregnancy. Two rabbits did not conceive. Spindles were placed correctly in 11 rabbits. Successful contraception was achieved in nine rabbits, who had 25 gestations on the nonspindle side and no gestation on the spindle side. One rabbit, which received the shortest spindle, was bilaterally pregnant, indicating a failure of contraception on the spindle side. No spindles dislocated. Histologic study showed all spindles firmly embedded in the tubal wall without signs of inflammation.Microspindles of a certain minimum length have potential as a transcervically implantable, permanent intratubal contraceptive device.A simple, nonsurgical female sterilization method involving fallopian tube catheterization under fluoroscopic guidance and implantation of microspindles was investigated in laboratory animals. A self-expanding microspindle made from tubular metal mesh was implanted in a single fallopian tube of 12 New Zealand Cross rabbits through catheterization of a single uterus. The contralateral fallopian tube and uterus served as controls. 8 rabbits completed three cycles of breeding and pregnancy; 2 rabbits had one pregnancy and 2 rabbits did not conceive (one presumably because of incorrect spindle placement). Successful contraception was achieved in 9 rabbits, who had 25 gestations on the nonspindle side and none on the spindle side. The rabbit with bilateral pregnancy (the recipient of the shortest spindle) represents one contraceptive failure in a total of 26 valid cycles. At autopsy, all spindles were firmly embedded in the tubal wall with no signs of inflammation. Complete obstruction of the interior space of the spindle was absent in all cases, indicating that complete occlusion of the tubal lumen was not the mechanism of action. A more likely explanation for the contraceptive effect observed in this study is the impairment of contractility of the spindle-carrying segment of the fallopian tube. These findings suggest that microspindles of a certain minimum length merit further investigation as a transcervically implantable, permanent intratubal contraceptive device.

The endovascular treatment of cerebral aneurysms using coils and stents, which are metal mesh cylinders, provides a promising alternative to open surgery. Although various analyses on the property of stented flow have been presented [1,2], the flow reduction mechanisms are not completely understood.Our numerical simulation indicates that the jet flow through stent struts can reduce near the aneurysm mouth but increases the flow speed far from the mouth (Fig. 1). In this work, based on this observation, we reveal the effect of the phenomenon that the pulsed jet flow drives the fluid with different velocity on the flow structure in the aneurysm cavity. As a result, we found a possibility that the shape of aneurysm may induce the self-oscillation of jet flow.We expect that our findings introduce new strategies in stent development and improve the endovascular treatment of cerebral aneurysms.[1] Biondi, A., et al., Neurosurgery, 61, 460-468 (2007)[2] Appanaboyina, S., et al., Int. J. Numer. Meth. Fluids, 57, 475-493 (2008)View Large Image | View Hi-Res Image | Download PowerPoint Slide

Nine cases of mandibular fracture are presented in which malleable metal mesh was used for internal fixation with and without supplemental intermaxillary fixation. Four representative case reports are presented. The technique, indications, advantages, and disadvantages of this method of mandibular fracture management are discussed.

Bilateral fractures were produced in edentulous mandibular bodies of ten adult male rhesus monkeys. A third fracture was produced in the symphyseal region. On one side of the mandible the fracture was reduced by means of a compression-fixation-clamp device. On the contralateral side, the fracture was reduced by means of a metal implant mesh fixed to the fracture fragments by means of intraosseous screws. The symphyseal fracture was not reduced so that the fracture fragment on one side would not effect the degree of mobility of the contralateral fracture. The compression device was found to provide firm clinical immobilization. Callus formation and the degree of osseous union initially were more pronounced at the 4-week level under the clamp than with the implant mesh. However, at 7 and 8 weeks postoperatively the degrees of osseous union were essentially the same under both the compression clamp and the implant mesh device. It would appear from this study that, compared to the intraosseous metal mesh fixation device, the compression clamp offers an environment through which a more rapid initial osseous union may be effected.