Polymer Mesh Research Articles

A SERS-Active Electrospun Polymer Mesh for Spatially Localized pH Measurements of the Cellular Microenvironment.

Extracellular pH (pHe) is an important chemical factor in many cellular processes and disease pathologies. The routine sampling of pHe in vitro could lead to innovative advances in therapeutics. To this end, we have fabricated a novel gold-coated polymer mesh, which facilitates the real-time measurement of pHe via surface-enhanced Raman scattering (SERS). In this proof of concept study, we apply our SERS sensor to measure metabolically induced changes in the pHe of carcinoma-derived cell line HepG2/C3A. We demonstrate that gold-coated polyurethane electrospun nanofibers (AuNF) have strong and reproducible SERS spectra of surface-adsorbed analytes. By functionalizing AuNF with pH-responsive reporter 4-mercaptobenzoic acid (MBA), we have developed an accurate pH SERS sensor for the extracellular microenvironment. We cultured HepG2/C3A on the surface of MBA-AuNF and measured an acidic shift in pHe at the cell-fiber interface. Following exposure to staurosporine, an apoptosis-inducing drug, we observed changes in the HepG2/C3A cellular morphology indicative of controlled cell death, and detected an increase in the pHe of HepG2/C3A. These results demonstrate how subtle changes in pHe, induced by the metabolic activity of cells, can be measured with our novel SERS sensor MBA-AuNF. The excellent pH measurement performance of MBA-AuNF provides a unique platform to study extracellular pH on the microscale and will help to deepen our understanding of pHe in disease pathology.

Use of polymeric mesh in guided bone regeneration

Introduction. Guided bone regeneration is a real challenge of dentoalveolar surgery. Due to modern biotechnology, the use of polymers in guided tissue regeneration is becoming a promising method in dentoalveolar surgery. Objective of the study. Assessment of the role of use of polymeric mesh in guided bone regeneration in patients with marked alveolar atrophy. Materials and methods. Beginning of the study - 2018, the study included 25 patients with marked alveolar atrophy, aged 20-60 years who were divided into two groups, group I - 15 patients underwent guided bone regeneration using polymers, in the group II - 10 patients used perforated titanium mesh. The diagnosis and treatment plan were similar for both groups. Results. In study group I, there were complications in 5 patients, of which 3 patients developed small fenestrations and seromas, and two patients developed dehiscence of 2/3 of the gum suture line. In the second group of patients, in which titanium mesh was used, complications developed in 7 patients - 4 patients developed fistulas and fenestrations and 3 suffered massive dehiscences along the entire suture line. Conclusions: The use of polymer mesh in guided bone regeneration is a cost-effective method in dentoalveolar surgery, cheap and simple to apply. This method recorded fewer postoperative complications, fewer surgical stages, faster postoperative recovery.

Enhancing esophageal repair with bioactive bilayer mesh containing FGF

We aimed to prepare a bioactive and biodegradable bilayer mesh formed by fibroblast growth factor (FGF) loaded gelatin film layer, and poly ε-caprolactone (PCL) film layer, and to investigate its treatment efficacy on esophageal anastomosis. It is envisaged that the bioactive mesh in in vivo model would improve tissue healing in rats. The full thickness semicircular defects of 0.5 × 0.5 cm2 were created in anterior walls of abdominal esophagus. The control group had abdominal esophagus isolated with distal esophageal blunt dissection, and sham group had primary anastomosis. In the test groups, the defects were covered with bilayer polymeric meshes containing FGF (5 μg/2 cm2), or not. All rats were sacrificed for histopathology investigation after 7 or 28 days of operation. The groups are coded as FGF(−)-7th day, FGF(+)-7th day, and FGF(+)-28th day, based on their content and operation day. Highest burst pressures were obtained for FGF(+)-7th day, and FGF(+)-28th day groups (p < 0.005) and decreased inflammation grades were observed. Submucosal and muscular collagen deposition scores were markedly increased in these groups compared to sham and FGF(−)-7th day groups having no FGF (p = 0.002, p = 0.001, respectively). It was proved that FGF loaded bioactive bilayer mesh provided effective repair, reinforcement and tissue healing of esophageal defects.

Features of diffusion processes in the preparation of prepregs by the method of layered application of components

The modern production of products made of composite materials based on thermosetting binders is mainly based on the use of pre – impregnated reinforcing technical threads-prepregs. The binder used for such semi-finished products must meet two important technological requirements: have a low reactivity (high viability) when stored in the temperature range from -5 to +25 ° C and the ability to adjust the curing time at the molding temperatures of the product. To eliminate the disadvantages of the traditional method of obtaining polymer composite materials, to improve their strength characteristics and reduce the cost of the resulting reinforced composites, it is proposed to use the method of layered application of components. The essence of the method consists in layer-by-layer impregnation of the fibrous filler with a binder solution, and then a developed curing system consisting of an amine hardener that prevents the interaction of the hardener with the resin under storage conditions and protective polymer emulsions. The binder-filler system is activated only at an elevated temperature under curing conditions. It is established that the optimal parameters for processing by direct pressing of the pre-pegs components obtained by the method of layer deposition are a pressure of 15 MPa and a temperature of160-170 ?С with a pressure exposure of 15 minutes. If you get products by winding, then for such products, heat treatment for 6 hours at a temperature of 120 ?С is optimal. In the conditions of forming products, that is, at an elevated temperature and at an increased pressure, the mutual diffusion of components occurs due to the movement of oncoming flows. Oligomeric molecules from the resin volume diffuse from the inner layer to the outer one, and the components of the curing system meet them from the outer layer to the inner one. The method of layered application of components makes it possible to create a macroheterogenic system of interpenetrating polymer meshes in the contact area of sequentially applied layers. The result of the research is an increase in the shelf life, the viability of prepregs (up to 10 days) and an improvement in the complex of physical and mechanical properties of composites: the destructive stress during static bending increases to 60 %, during dynamic bending (impact) - up to 50 %. The use of carboxymethylcellulose as a protective polymer provides higher indicators of the studied properties than when using butadiene styrene latex as a protective polymer..

Comparative study of confining reinforcement used for the rectangular concrete short column

Columns play a major role in reinforced concrete building frames. It is observed that one of the cause of the failure is the insufficient confining reinforcement provided in the columns. The transverse reinforcement provided in the columns also plays a crucial role in preventing the failure of the column under critical conditions. Only the lateral ties used in the columns do not provide safety against deformation and damage. Hence, columns need to be strengthened by providing additional material as a means of confining reinforcement. In this research work, a comparative study of rectangular reinforced concrete short columns is presented. The experimental study of ten different column configurations was carried out using confining materials such as welded wire mesh, ferro cement wall panels, glass fiber mesh, nylon polymer mesh, spot welding, combination of welded wire mesh and chicken mesh, additional diagonal ties and stapled stirrups. Each of the ten configurations consists of three sets of M25 grade columns of size 150×230×550mm. The columns were tested under axial compressive load and the test results were compared with respect to ultimate load carrying capacity of the columns, vertical and lateral deformation of the columns, ductility, practical feasibility and the cost of the columns. The test result shows that the ultimate load carrying capacity of the column for all means of confinement was increased from 16.48 % to 89.24%. A significant improvement in ductility was also observed. Columns confined with nylon polymer mesh (NPM) were found to be efficient and economical as compared to other materials used for confinement.

Forms of sternal reconstruction in oncology

INTRODUCTION. Chest wall tumors represent a variety of morphological forms and variants of lesions. According to different authors, primary malignant tumors of the chest wall account for 0.2–2 % of all malignant neoplasms. Of them, soft tissue sarcomas constitute about 45 %. Metastatic tumors of the chest wall occur much more frequently and most commonly develop from malignant tumors of the mammary, prostate and thyroid glands, lungs, kidneys and ovaries.MATERIALS AND METHODS. The standard of the treatment of primary and metastatic tumors of the chest wall is combination or comprehensive therapy. In some cases, preoperative care allows to create a more favorable environment for performing surgical treatment being considered the best option for chest wall tumors. The choice of a technique for the replacement of the post-resection chest wall defect is of special importance to preserve the physiological chest volume, to restore chest rigidity, to prevent paradoxical respiration and to seal the pleural cavity.RESULTS. There are different surgical techniques for skeleton reconstruction. A wide range of materials used for a skeleton reconstruction include bone tissues obtained from patient’s own body (bone autoplasty, autografts), polymeric mesh (polypropylene, polytetrafluoroethylene (Gore-Tex), bone cement (polymethyl methacrylate), stainless steel and titanium constructions as well as titanium bars and rib clips (STRATOS). In spite of a large number of techniques for sternal reconstruction described in the literature, searching for new materials and ways of their usage appears relevant.CONCLUSION. Our clinical case studies demonstrate that modern reconstructive techniques combined with careful surgical planning allow to perform radical surgery with a successful outcome preventing serious postoperative complications.

Finite element parametric analysis of RC columns strengthened with FRCM

Fiber reinforced cementitious matrix (FRCM), a noncorrosive two-dimensional high strength fiber reinforced polymer (FRP) mesh saturated with inorganic cementitious mortar is evolving as a viable option for retrofitting damaged RC structures. While numerous studies investigated the potential of FRCM strengthening in shear and flexural applications, limited studies explored the confinement of short and slender columns, particularly using finite element (FE) analysis. In this study, a three-dimensional (3D) nonlinear finite element (FE) model is developed using ABAQUS to study the behavior of corrosion damaged RC columns retrofitted with poly-paraphenylene-ben-zobisoxazole (PBO) FRCM systems. Geometric and material nonlinearities in concrete, cement mortar and composite are incorporated in the FE model that is validated through axial capacity and failure mode comparisons against published literature. A comprehensive parametric study involving 180 models is conducted considering the effects of five parameters: (a) cross section type (square vs circular), (b) FRCM wraps (1, 2, 3 and 4 layers), (c) pre-damage level (mild, moderate and severe), (d) eccentricity ratio (0.0, 0.3, 0.5, 0.75, 1.0, 1.25 and 1.5) and (e) column length (short and slender). Concrete compressive strength of 30 MPa and a longitudinal reinforcement ratio of 2% are adapted in all models. Results indicated that retrofitting corrosion damaged RC columns with PBO-FRCM effectively resorted and enhanced the original axial capacity and ductility of all column specimens and at all damage levels. A positive correlation between number of FRCM layers and axial capacity and ductility enhancement was observed and was more pronounced in circular columns. Increasing the number of FRCM layers also increased the axial capacity of eccentrically loaded columns irrespective of damage level and eccentricity ratio. Finally, comparison of axial capacity using ACI 549.4R-13 provisions against FE results disclosed that the code provisions underestimated the axial capacity of short RC columns retrofitted with PBO-FRCM by about 20%.

Shake table tests on a tuff masonry structure strengthened with composite reinforced mortar

The seismic vulnerability of unreinforced masonry structures threatens the life and health of people and the conservation of the built heritage in earthquake prone areas, highlighting the need of gaining a deeper understanding of their dynamic behaviour and of developing appropriate strengthening technologies. This work investigates the effectiveness of a low-impact technology consisting of composite reinforced mortar (CRM) applied to the outer surface of masonry walls for enhancing their seismic capacity, without the need to evacuate the building. Shake table tests were performed under natural accelerograms (applied in horizontal and vertical directions) on a real-scale structure, built with tuff blocks and consisting of a façade with a window, two side walls (one of which with a door near the corner) and an inclined timber roof. The mock-up was tested unstrengthened, then repaired and strengthened by applying a glass fibre reinforced polymer mesh embedded in a lime-based plaster to the outer surface of damaged walls. The experimental investigation showed the effects of CRM on damage accumulation, failure mode and on the increase of base acceleration and displacement capacities.

The regulation of electric-optical properties of polymer-dispersed liquid crystals via implantation of polyhedral oligomeric silsesquioxane (POSS) microstructure

ABSTRACT In this paper, we report a simple and effective technique to improve the electro-optical performance of polymer-dispersed liquid crystal (PDLC) films via the implantation of polyhedral oligomeric silsesquioxane (POSS) microstructure into the polymer matrix. The measurement results of the electro-optical properties indicated that the electro-optical performances of PDLC films have been regulated successfully via the implantation of POSS microstructure into the polymer matrix. SEM results suggested that the size of polymer meshes was broadened with the increase in the content of POSS microstructure, while the static water contact angles of the polymers increased after the implantation of POSS microstructure. Because of the lower surface energy as well as the increased steric repulsions between liquid crystal molecules and polymer surfaces, the anchoring effect of the polymer matrix containing POSS microstructure was concluded to be weakened, which was the dominant factor in achieving the dramatic regulation effect of the electro-optical properties of the PDLC films. This work could provide a creative approach for the fabrication of low voltage-driven PDLC films for their practical applications.

Dismantling of the powered complex using a dismantling shield in the conditions of Southern Kuzbass mines

The experience of works on dismantling powered coal face systems at the mines of Kuzbass and the USA is discussed. The factors influencing the duration of dismantling of powered complexes are determined. Based on the experience of dismantling works, a scheme with a polymer mesh canopies and pilot sections of powered mining complexes with the formation of a chamber by a face has become widespread. To reduce the time for dismantling works, a technology with the use of dismantling shield (two “pilot” sections connected by an E-frame), which allows the minimum possible time for reassembly of the coal face system equipment to be achieved.

Triboelectric Laminates with Volumetric Electromechanical Response for Mechanical Energy Harvesting

AbstractThe main requirement for triboelectric nanogenerator devices is the necessity to have separable or movable parts to harvest mechanical energy, thus complicating their integration into the energy harvesting systems. Herein, triboelectric laminates that show a volumetric electromechanical response are introduced, similar to intrinsic ferroelectric polymers. The laminates are composed of stacked bilayer polymer films with different triboelectric surface properties separated by polymer mesh. This sophisticated design provides dipole alignment across the volume of triboelectric laminate and electromechanical response without applying any poling procedure. Triboelectric laminate generates the open‐circuit voltage (VOC) of 29 V and short‐circuit current (ISC) of 15 nA. Volumetric energy density of 21.13 µJ cm−3 and a peak average power density of 46.19 µW cm−3 are observed. Triboelectric laminate shows an effective piezoelectric constant d33 of 9.83 pC N−1, higher than reported for piezoelectric polymer like nylon‐11. The triboelectric laminate is produced from cheap, mechanically flexible materials that can be produced in large quantities.

A Polymer-Biologic Hybrid Hernia Construct: Review of Data and Early Experiences.

Surgical mesh reinforcement of the human abdominal wall has been found to reduce the chance of recurrence in hernia repairs. While traditionally polymer meshes have been used in hernia repair, alternative mesh options have been engineered to prevent the inflammatory foreign body response invoked by polymers. A reinforced tissue matrix (RTM) mesh has been developed by embedding a polymer within a decellularized extracellular matrix. This combination has been attributed to the recruitment of host cells, a pro-healing response, and attenuation of the foreign body response. This has been observed to lead to the regeneration of functional tissue within the repair site that is reinforced by the polymer to offload abdominal pressures over time. This manuscript presents the review of OviTex, an RTM, in several types of hernia repair. The authors have found that the use of RTM in hernia repair is effective in preventing foreign body response, promoting wound healing, and providing reinforcement to lower the risk of hernia recurrence.

Suspended 1D Metal Oxide Nanowire Junction Networks for Use As Highly Sensitive Gas Sensors

Introduction Over the last few decades, research has been conducted to build sensitive, reliable and high-performance gas monitoring systems that meet the demands of industrial sites. In particular, 1D metal oxide (MOx) nanomaterials have been actively studied as a gas sensing material because of its excellent sensing performance, low cost, and suitability for a micro/nano device [1]. Besides, the MOx 1D nanostructures are relatively easy to synthesize, easy to control morphology and have various options including surface functionalization to make even further enhancement of the sensing performance [2]. In particular, when the MOx 1D nanostructures linked together and form a junction structure, an additional current path is generated through the formed junction and this forms additional potential barriers. Thus, an additional gas sensing mechanism can be utilized to further improve sensing performance as shown in Figure 1 [3]. In general, however, the fabrication process of MOx nanostructure networks including dense junctions requires complex and precise techniques. In addition, the nanostructure networks are positioned on the substrates. Therefore, gas access to the junctions and mass transfer to the sensing sites are limited. In this study, we report a novel gas sensor architecture including a suspended carbon mesh integrated with ZnO nanowires networks. The nanowires are grown on single carbon wires of the mesh and meet at the void regions of mesh structures. Thus, dese nanowire junctions can be formed in a suspended form (Figure 2). Owing to the suspended architecture, gas access to the sensing sites is effective and the sensing signal is free from the effect of the substrate [4]. The suspended carbon nanomesh was fabricated using the carbon-MEMS process consisting of simple photolithography and pyrolysis processes. The ZnO nanowire networks were precisely patterned at the suspended mesh using the hydrothermal method. The length of the nanowires was adjusted for good junction formation and the advantage of the suspended junctions was evaluated. Method Suspended carbon nanomesh was fabricated by photolithography and pyrolysis (Vacuum, 700°C) processes. Via two successive exposure steps in photolithography, suspended polymer mesh was defined without complex lithography techniques. After the pyrolysis process, microscale polymer mesh was converted into nano-sized carbon mesh because of the large volume reduction (up to 90%) in pyrolysis. After a thin ZnO seed layer was selectively coated on the suspended carbon mesh, ZnO nanowires were grown on the patterend seed layer by a hydrothermal process (Zn(NO3)2 25mM, HMTA 25mM ). The pristine ZnO nanostructures were annealed using RTA (N2 atmosphere, 300°C) for better adhesion and connection. Results and Conclusions Figure 2 shows the SEM images of the fabricated suspended carbon nanomesh (width ~140μm, thickness ~400nm, line spacing ~6μm) and ZnO nanowire networks (diameter ~100 nm, length ~3.5 μm). ZnO nanowires were well grown to form uniform and dense junctions. To characterize the effect of the nanowire junctions, NO2 gas sensing responses were compared between a nanomesh-based gas sensor and a single suspended carbon wire-based sensor. As shown in Figure 3. the suspend mesh-based sensor exhibited higher response and wider linear range due to the effect of junctions. This novel sensor architecture can be widely utilized because all the fabrication processes of the presented sensor were carried out at a wafer-level making it cost-effective and various MOx nanowires can be simple integrated with a bunch of junctions.

An investigation into the feasibility of normal and fibre-reinforced ultra-high performance concrete multi-cell and composite sandwich panels

Inspired by the concept of box girders and bubble deck systems, the present study investigates and develops new forms of composite structures and their behaviours are investigated. The sandwich system implements two basalt fibre-reinforced polymer (BFRP) mesh reinforced ultra-high performance concrete (UHPC) plates as face sheets and a combination of normal strength mortar (NSM) and expanded Polystyrene (EPS) foam as core layers in varying configurations. The box-cell system is produced by UHPC cast into galvanised steel roofing sheet profiles with anchor screws and EPS foam positioned in-situ to produce a box-celled panel. Both systems have three variations for which the structural responses of these panels as one-way slabs under three-point flexure are studied. In addition to the experimental investigations, the sandwich panel theory (EST), advanced sandwich theory (AST), segmental sectional analysis and finite-element analysis are applied to predict the behaviour of the panels at their serviceability limit states. The findings indicate that partially replacing the core with EPS in the sandwich system can effectively reduce the self-weight of the slab without compromising its load capacity under flexure. Moreover, the box-cell system is the most effective when steel fibres are added to the UHPC mix by increasing ductility and preventing early delamination of the steel profile from the UHPC. The modified EST, AST, and sectional analysis can successfully simulate the behaviour of the composite panels within their linear elastic material conditions and the finite-element analysis can accurately model the full-range behaviour of the box-cell composite panels.

Eco-friendly polyacrylic acid based porous hydrogel for heavy metal ions adsorption: characterization, adsorption behavior, thermodynamic and reusability studies

Hydrogels are the most commonly used 3D polymer mesh materials for environmental removal due to their ability to hold water in their porous structures. In this study, polymeric hydrogels were used for metal removal from wastewater. Polyacrylic acid is an environmentally friendly polymer with known biodegradable and antimicrobial properties. Polyacrylic acid based (PAA) hydrogel were used as an adsorbent for removal of the M2+ (Cd2+, Ni2+ and Cu2+) and Fe3+ ions from aqueous solutions in this study. Eco-friendly functional PAA-based hydrogel was obtained by in-situ free radical polymerization technique. The effect of pH on the swelling characteristic of hydrogel was examined exhaustively and the highest swelling capacity as 1200% was seen for 2% cross-linked PAA hydrogel at pH 10. All these samples gave highly impressive results in the adsorption of Cu2+, Cd2+, Ni2+, and Fe3+ from water solutions at pH values between 2 and 10. The highest adsorption capacity of the metal ions on hydrogel was specified as Cd2+ ion. Due to its clean production process, high heavy-metal adsorption capacity and the re-usability, PAA-based hydrogels have a high potential as an eco-friendly cleaner production material.

Research on mechanical performance of industrial polypropylene biaxial geogrid

Biaxial plastic geogrid is a polymer mesh formed by biaxial stretching. When making biaxial plastic geogrids, generally, the polymer sheet made by extrusion is pre-punched first, and then the biaxial stretching is carried out at an appropriate temperature. Different sizes of pre-punched holes will affect the subsequent stretching process, thereby changing the mechanical properties of the grid. In this study, geogrids made of different pre-punched diamond-shaped hole plates were subjected to room temperature tensile test. Influence of diameter-to-distance ratio and the percentage difference of longitudinal and transverse spacing on the mechanical properties of biaxial geogrids were studied experimentally and numerically. The results show that when the holes are appropriately small and the longitudinal spacing between the holes is slightly larger than the transverse spacing, the mechanical properties of the grid can be the best, and transverse stretching process will affect the longitudinal ribs in different aspects.

Earthen claddings in lightweight timber framed buildings: An experimental study on the influence of fir boards sheathing and GFRP jacketing

The aim of this research was to investigate the mechanical performance of an earthen massive cladding, recently used for external/internal layers in Platform Frame technology, through an extensive experimental campaign. The masonry is built with extruded unbaked earth blocks and characterized by dovetail horizontally staggered bed joints. The wall is secured to the structural timber studs through 45 degree-angled fir boards sheathing panels, fixed with steel connectors, and finished with an external plaster with an embedded Glass Fibre Reinforced Polymer (GFRP) mesh, wrapping the whole masonry. The influence of the fir board panels and GFRP jacketing on the mechanical behavior of the earth blocks masonry is investigated and compared with the results obtained for the unreinforced configuration (bare wallettes) in (Stazi et al., 2020). The experimental program consisted of compression, diagonal compression and combined shear-compression tests on 18 wallettes. Digital Image Correlation technique was also adopted to investigate the full field strain maps. The results showed that under compression all the samples (with and without reinforcements) behave as a series of independent slender columns, without significant differences among reinforcement type. Both diagonal compression and shear with compression tests revealed the optimal behavior of GFRP plaster reinforcement that increases the strength values and thanks to an effective confinement effect, limits the out-of-plane bending and determines a monolithic response of the wall.

Development of titanium 3D mesh interlayer for enhancing the electrochemical performance of zinc\u2013bromine flow battery

Zinc dendrite growth negatively affects zinc–bromine flow battery (ZBB) performance by causing membrane damage, inducing self-discharge. Herein, in a ZBB, a conventional polymer mesh was replaced with a titanium-based mesh interlayer; this provided additional abundant active sites for the Zn2+/Zn redox reaction and well-developed electrolyte flow channels, which resulted in improved reaction kinetics and suppressed Zn dendrite growth. Compared with a ZBB cell comprising a conventional polymer mesh and a carbon-based electrode, the ZBB cell using the titanium mesh interlayer and a carbon-based electrode showed significantly reduced frequency of the refreshing process, which occurs at regular cycling intervals during practical use for removing residual zinc dendrites in ZBB; also, the average energy efficiency at a current density of 40 mA cm−2 increased by 38.5%. Moreover, the modified ZBB cell exhibited higher energy efficiency at a high current density of 80 mA cm−2, which is an improvement of 14.7% than in case of the contemporary polymer mesh. Consequently, this study can provide helpful insights for new anode side structures including spacer mesh for developing high-performance ZBBs.

Incidence and clinical impact of vertebral endplate changes after limited lumbar microdiscectomy and implantation of a bone-anchored annular closure device

BackgroundAn annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation.MethodsThis analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS, ODI), radiological outcome (reherniation, implant integrity, volume of EPC) and risk factors for EPC were assessed.ResultsSeventy-two patients (37 men, 47 ± 11.63yo) underwent LMD and ACD implantation between 2013–2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67 ± 4.77 months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p = 0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n = 10; asymptomatic: n = 7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n = 1, 1.3%), dislocation of the whole device (n = 5, 6.9%), and mesh dislocation into the spinal canal (n = 13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device.ConclusionClinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc reherniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Flexural strength of polymethyl methacrylate reinforced with high-performance polymer and metal mesh

Background: The flexural strength (FS) of a denture base material is of great concern, and many approaches have been used to strengthen the denture acrylic resins. The present study aimed to evaluate the effect of high-performance polymer (BioHPP) and metal mesh reinforcement on the FS of a heat-cured poly methyl methacrylate (PMMA) acrylic resin. Materials and Methods: This experimental study was done on 30 rectangular specimens (64 mm × 13 mm × 3 mm) of a heat-cured PMMA resin. The specimens were divided into three groups (n = 10) to be reinforced with either metal mesh or BioHPP mesh; one group was left nonreinforced, serving as the control group. The FS of specimens was assessed through a 3-point bending test by using a universal testing machine at a crosshead speed of 2 mm/min. Kruskal–Wallis H and Dunn's post hoc tests were used to compare the FS among the groups (alpha = 0.05). Results: The FS in the metal-reinforced group was statistically significantly higher than the two other groups (P &lt; 0.001). However, the FS of the BioHPP-reinforced samples was not statistically significantly higher than the nonreinforced ones (P = 0.614). Conclusion: Reinforcing the PMMA with metal mesh significantly enhances its FS while BioHPP has no significant effect on the PMMA FS.