Porosity and pore design influence on fatigue behavior of 3D printed scaffolds for trabecular bone replacement.
Abstract Polymeric scaffolds provide several advantages when compared with other bone replacement and regenerating techniques. Namely, when compared with the current gold standard, bone autografts, there is no shortage of supply nor donor site morbidity. Contrarily to metallic implants, their mechanical properties are similar to those of cortical bone and they are biodegradable, therefore stress shielding is not expected to occur, and they will be gradually replaced by new bone tissue. Yet, there are still several challenges to overcome. After implantation scaffolds are subjected to dynamic loads, thus understandi...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 15, 2021 Category: Materials Science Authors: Baptista R, Guedes M Tags: J Mech Behav Biomed Mater Source Type: research

A deep learning application to approximate the geometric orifice and coaptation areas of the polymeric heart valves under time - varying transvalvular pressure.
In this study, our objective was to apply a deep learning framework to predict the geometric orifice (GOA) and the coaptation areas (CA) of the polymeric heart valves under the time-varying transvalvular pressure. 377 different valve geometries were generated by changing the control coordinates of the attachment and the belly curve. The GOA and the CA values were obtained at the maximum and the minimum transvalvular pressure, respectively. The results showed that the applied framework can accurately predict the GOA and the CA despite being trained with a relatively smaller data set. The presented framework can reduce the r...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 12, 2021 Category: Materials Science Authors: Gulbulak U, Gecgel O, Ertas A Tags: J Mech Behav Biomed Mater Source Type: research

Stress distribution analysis of oral mucosa under soft denture liners using smoothed particle hydrodynamics method.
This study aims to simulate the stress distributions of oral mucosa under different soft denture liners using the smoothed particle hydrodynamics (SPH) method. The Young's modulus and viscosity of denture liners composed of silicone (Sofreliner Super Soft and Sofreliner Tough Medium, Tokuyama Dental), acrylic (Vertex Soft, Vertex Dental), and a tissue conditioner (Visco-gel, Dentsply Sirona) were measured using a creep meter. A numerical simulation model that represents the stress distribution of oral mucosa under soft denture liners was also developed using the SPH method. The oral mucosa was divided into four regions: A)...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 12, 2021 Category: Materials Science Authors: Onuma H, Inokoshi M, Hirayama D, Inoue M, Minakuchi S Tags: J Mech Behav Biomed Mater Source Type: research

Comparative research on morphology and mechanical property of integument of Rana dybowskii, Xenopus laevis and Ambystoma mexicanum.
Abstract Amphibians' integument is a multifunctional organ offering protection from the exterior surroundings and facilitating the physiological change of gas, water and salts with the environment, which is a natural biomaterial with multifunctional features. Interspecies comparison of biomechanical characters and microstructure possibly related to them were performed on the integument of three species of amphibians, two anurans(Rana dybowskii and Xenopus laevis) and one urodeles(Ambystoma mexicanum) using tensile testing and morphological characterization. It was found that the integument of Rana dybowskii and Xe...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 11, 2021 Category: Materials Science Authors: Li M, Gao Z, Dai T, Chen D, Tong J, Guo L, Wang C Tags: J Mech Behav Biomed Mater Source Type: research

Damage evaluation of HAp-coated porous titanium foam in simulated body fluid based on compression fatigue behavior.
Abstract Although pure Ti is nontoxic, alloying elements may be released into the surrounding tissue when Ti alloys are used, and this can cause cytotoxicity. Therefore, this study performed the damage evaluation of hydroxyapatite (HAp)-coated porous Ti components subjected to cyclic compression in a simulated body fluid (SBF). The HAp coating layer was deposited on the surface of porous Ti by electrophoresis, and a dense and homogeneous coating morphology was observed on the surface of the porous Ti. To specify damage types of HAp coating in situ, acoustic emission (AE) measurements and microscopic observations w...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 11, 2021 Category: Materials Science Authors: Raihan MM, Otsuka Y, Tsuchida K, Manonukul A, Ohnuma K, Miyashita Y Tags: J Mech Behav Biomed Mater Source Type: research

Mechanical properties of ester- and ether-DPhPC bilayers: A molecular dynamics study.
Abstract In addition to its biological importance, DPhPC lipid bilayers are widely used in droplet bilayers, study of integral membrane proteins, drug delivery systems as well as patch-clamp electrophysiology of ion channels, yet their mechanical properties are not fully measured. Herein, we examined the effect of the ether linkage on the mechanical properties of ester- and ether-DPhPC lipid bilayers using all-atom molecular dynamics simulation. The values of area per lipid, thickness, intrinsic lateral pressure profile, order parameter, and elasticity moduli were estimated using various computational frameworks a...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 11, 2021 Category: Materials Science Authors: Rasouli A, Jamali Y, Tajkhorshid E, Bavi O, Pishkenari HN Tags: J Mech Behav Biomed Mater Source Type: research

Evaluation of two CAD/CAM materials for Nayyar core and post-retained restorations: Three dimensional stress analysis.
CONCLUSIONS: The comparison of the two techniques showed that PRR had better stress distribution than NCR. NCR or PRR with LU or VE exhibited similar VM stress accumulation in dentin. Maximum principle stress analyses showed that PRR with LU transmitted the least stress to enamel and dentin indicating that when LU is the material of choice, post-retained restoration would be a satisfactory design. VM stress values of enamel revealed that VE absorbed the stress in itself and transferred less stress to dentin. This could point out that for the restoration of maxillary first premolar tooth with missing palatal cusp, VE may be...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 5, 2021 Category: Materials Science Authors: Ulusoy N, Gulec Alagoz L Tags: J Mech Behav Biomed Mater Source Type: research

Validation of a finite element model of the thoracolumbar spine to study instrumentation level variations in early onset scoliosis correction.
The objective of the current study was to validate a parametric FE model of the thoracolumbar spine including its ability to predict the biomechanical effects of varying the number of levels instrumented with UHMWPE sublaminar tape in a growth-guidance construct for EOS correction. In a first step, the material properties of the L4-L5 segment in the model were calibrated relative to literature data. Next, whole thoracolumbar spine behavior was verified relative to literature data as well. Subsequently, rods, screws, and sublaminar tape were implemented in the model and a simulation of a previously performed in vitro experi...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 4, 2021 Category: Materials Science Authors: Roth AK, Beheshtiha AS, van der Meer R, Willems PC, Arts JJ, Ito K, van Rietbergen B Tags: J Mech Behav Biomed Mater Source Type: research

Functional repair of critically sized femoral defects treated with bioinspired titanium gyroid-sheet scaffolds.
Abstract Despite the innate ability for bone to remodel and repair, its regeneration has a limit. In these cases of critically sized bone defects (CSBD), the bone deficit must be repaired using reconstructive techniques that support immediate load bearing and encourage bone bridging across the defect. High-strength porous titanium implants offer a solution for treatment of CSBD in which the scaffold can support physiological loads, provide a matrix to guide ingrowth, and carry graft materials and/or biologics. Fabrication of titanium meta-materials via additive manufacturing (AM) has unlocked the potential to modu...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 4, 2021 Category: Materials Science Authors: Kelly CN, Lin AS, Leguineche KE, Shekhar S, Walsh WR, Guldberg RE, Gall K Tags: J Mech Behav Biomed Mater Source Type: research

Effect of strontium substitution on structural, sinterability, physicomechanical and biological properties of akermanite ceramic.
Abstract Despite the excellent in vitro and in vivo performance of akermanite ceramic, its poor toughness and strength limit the biomedical application, particularly under load. Herein, the incorporation of strontium enhanced the physicomechanical properties of akermanite and this is ascribed to the decrease in grain size and better sinterability. To investigate the biological performance, the bone-cell interaction with sintered pellets was assessed by in vitro biocompatibility with human fetal osteoblast cell (hFOB). The cell viability using MTT assay revealed that the Ca1.9Sr0.1MgSi2O7 pellets with finer grain s...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 4, 2021 Category: Materials Science Authors: Mohammadi H, Baba Ismail YM, Shariff KA, Mohd Noor AF Tags: J Mech Behav Biomed Mater Source Type: research

Edge chipping resistance of veneering composite resins.
Abstract OBJECTIVES: To investigate the edge chipping resistance (ECR) of six veneering composite resins after different treatment protocols. MATERIALS AND METHODS: Rectangular bar specimens were manufactured from Ceramage Incisal (CER; Shofu), dialog Vario Occlusal (DIA; Schütz Dental), Gradia Plus Heavy Body Enamel (GRA; GC Europe), in:joy incisal (INJ; Dentsply Sirona Deutschland), SR Nexco Paste Incisal (SRN; Ivoclar Vivadent), and Signum composite enamel (SIG; Kulzer). ECR was determined after five treatment protocols: (1) no treatment, (2) after storage in distilled water at 37 °C for 7 da...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 2, 2021 Category: Materials Science Authors: Zadeh PN, Stawarczyk B, Hampe R, Liebermann A, Mayinger F Tags: J Mech Behav Biomed Mater Source Type: research

Compositional, microstructural and mechanical effects of NaCl porogens in brushite cement scaffolds.
In this study the synergistic effect of NaCl and citric acid on the microstructural evolution of brushite cement was demonstrated and microporosity of macroporous monetite-rich cement blocks was minimized by a variable NaCl porogen size distribution approach. Initially, maximum packing ratio of various combinations of NaCl size groups in PEG were determined by their rheological analysis in a range between 57% and 69%. Statistical analysis revealed a positive correlation between the amounts of NaCl particles under 38μm and 212μm and the maximum packing ratio. Further broadening the size distributions of NaCl porogens ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 1, 2021 Category: Materials Science Authors: Şahin E, Çiftçioğlu M Tags: J Mech Behav Biomed Mater Source Type: research

Physical and thermo-mechanical properties of shape memory polyurethane containing reversible chemical cross-links.
In this study, in order to obtain a suitable polymer for this application as well as troubleshoot the main drawbacks such as stress relaxation and water absorption, thermoplastic polyurethane (TPU) elastomers with various compositions were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analyses. Mechanical properties of samples were evaluated by tensile, elasticity, and stress relaxation tests. According to the required properties for orthodontic chain application, PU2000-311 which contains reversible crosslinks, was sele...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 1, 2021 Category: Materials Science Authors: Mehrbakhsh E, Rezaei M, Babaie A, Mohammadi A, Mayan Sofla RL Tags: J Mech Behav Biomed Mater Source Type: research

A mechanical analysis informed fractography study on load-specific fatigue behaviors of Pt-Ir coils used in implantable medical leads.
Abstract Fatigue fracture is a major threaten to implantable medical coils such as platinum-iridium (Pt-Ir) coils used in deep brain stimulation leads. The fractography under bending and torsion fatigue was studied in comparison with mechanical analysis to grasp load-specific fatigue characteristics and understand the mechanisms. Mechanical analysis of the coil under bending and torsion was conducted with both analytical and numerical methods. Pt-Ir coils were experimentally fatigued at roughly paralleled bending and torsional load levels. The fatigue life was recorded and the fracture morphology was observed and ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - February 1, 2021 Category: Materials Science Authors: Li L, Jiang C, Wang H, Xie H, Li L Tags: J Mech Behav Biomed Mater Source Type: research

Mechanical properties of ceramic composites based on ZrO2 co-stabilized by Y2O3-CeO2 reinforced with Al2O3 platelets for dental implants.
CONCLUSIONS: The composites (Ce,Y)-TZP/Al2O3 showed high resistance to degradation in saliva and adequate properties for use as dental implants. Values of flexural strength (>950 MPa) and Weibull modulus (m > 10) were similar to the conventional 3Y-TZP ceramics. Moreover, its hardness, elastic modulus and fracture toughness were higher than those obtained for 3Y-TZP. The expressive values of KIC obtained for (Ce,Y)-TZP/Al2O3 composites are results of association of different toughening mechanisms acting simultaneously in the material. PMID: 33540326 [PubMed - as supplied by publisher] (Source: Jou...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 31, 2021 Category: Materials Science Authors: Santos CD, Coutinho IF, Amarante JEV, Alves MFRP, Coutinho MM, Moreira da Silva CR Tags: J Mech Behav Biomed Mater Source Type: research

Physicochemical properties, bond strength and dual-species biofilm inhibition effect of dental resin composites with branched silicone methacrylate.
Abstract Dental resin composites (DRCs) with 15 wt% (EC-15%) and 20 wt% (EC-20%) synthesized branched silicone methacrylate (BSM) in resin matrix have showed anti-adhesion effect against Streptococcus mutans. With the aim to evaluate the BSM containing DRCs further, water sorption (WS), solubility (SL), mechanical properties before and after water immersion, anti-adhesion effect against dual-species, bonding strength to adhesive treated dentin, and cytotoxicity of BSM containing DRCs were investigated. DRC without BSM was used as control. The WS and SL were obtained until the mass variation of composite ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 30, 2021 Category: Materials Science Authors: Tong H, Yu X, Shi Z, Liu F, Yu Y, Deng F, He J Tags: J Mech Behav Biomed Mater Source Type: research

Effect of load-induced local mechanical strain on peri-implant bone cell activity related to bone resorption and formation in mice: An analysis of histology and strain distributions.
kabayashi N Abstract The purpose of this study was to investigate the effect of load-induced local mechanical strain on bone cell activity of peri-implant bone in mice. Titanium implants were placed in the maxillae of 13-week-old male C57BL/6J mice and subjected to intermittent 0.15 N, 0.3 N, or 0.6 N loads for 30 min/day for 6 days. The animals were sacrificed 2 days after the final loading. Unloaded mice were used as controls. An animal-specific three-dimensional finite element model was constructed based on morphological data retrieved from in vivo microfocus computed tomography for each mou...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 30, 2021 Category: Materials Science Authors: Okawara H, Arai Y, Matsuno H, Marcián P, Borák L, Aoki K, Wakabayashi N Tags: J Mech Behav Biomed Mater Source Type: research

Mechanical properties and water-aging resistance of glass ionomer cements reinforced with 3-aminopropyltriethoxysilane treated basalt fibers.
Abstract In order to improve interfacial adhesion between basalt fibers (BF) and glass ionomer cement (GIC) matrix, a silane named 3-aminopropyltriethoxysilane (APS) was used to modify the surface of BF. APS treated BF (APS-BF) was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The influence of APS concentration on mechanical properties of APS-BF reinforced GIC (APS-BF-GIC) was investigated, and water aging resistance of optimum APS-BF-GIC was also studied. The results showed that 5 wt% of APS was the optimum co...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 30, 2021 Category: Materials Science Authors: Bao X, Liu F, He J Tags: J Mech Behav Biomed Mater Source Type: research

Evaluation of the role of peripheral artery plaque geometry and composition on stent performance.
Abstract Peripheral stent fracture is a major precursor to restenosis of femoral artery atherosclerosis that has been treated with stent implantation. In this work, we validate a workflow for performing in silico stenting on a patient specific peripheral artery with heterogeneous plaque structure. Six human cadaveric femoral arteries were imaged ex vivo using intravascular ultrasound virtual histology (IVUS-VH) to obtain baseline vessel geometry and plaque structure. The vessels were then stented and the imaging repeated to obtain the stented vessel lumen area. Finite element (FE) models were then constructed usin...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 25, 2021 Category: Materials Science Authors: Noble C, Carlson KD, Neumann E, Doherty S, Dragomir-Daescu D, Lerman A, Erdemir A, Young M Tags: J Mech Behav Biomed Mater Source Type: research

Synchrotron-based micro computed tomography investigation of the implant-abutment fatigue-induced microgap changes.
CONCLUSION: Regardless of the crown height, the microgap between the abutment and implant systematically decreased after loading in both butt-joint and internal-conical connections. PMID: 33516129 [PubMed - as supplied by publisher] (Source: Journal of the Mechanical Behavior of Biomedical Materials)
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 23, 2021 Category: Materials Science Authors: Bagegni A, Zabler S, Nelson K, Rack A, Spies BC, Vach K, Kohal R Tags: J Mech Behav Biomed Mater Source Type: research

Biomechanical properties of acellular scar ECM during the acute to chronic stages of myocardial infarction.
In this study, we decellularized MI scar tissue and characterized the biomechanics of the obtained pure scar ECM. By thoroughly removing the cellular content in the MI scar tissue, we were able to avoid its confounding effects. Rat MI hearts were obtained from a reliable and reproducible model based on permanent left coronary artery ligation (PLCAL). MI heart explants at various time points (15 min, 1 week, 2 weeks, 4 weeks, and 12 weeks) were subjected to decellularization with 0.1% sodium dodecyl sulfate solution for ~1-2 weeks to obtain acellular scar ECM. A biaxial mechanical testing system was used to characteriz...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 22, 2021 Category: Materials Science Authors: Brazile BL, Butler JR, Patnaik SS, Claude A, Prabhu R, Williams LN, Perez KL, Nguyen KT, Zhang G, Bajona P, Peltz M, Yang Y, Hong Y, Liao J Tags: J Mech Behav Biomed Mater Source Type: research

Shear behavior of human skull bones.
Abstract A shear-punch test (SPT) experimental method was developed to address the lack of shear deformation and failure response data for the human skull as a function of local bone microarchitecture. Improved understanding of skull deformation and fracture under varying stress-states helps implement mechanism-based, multi-axial material models for finite element analysis for optimizing protection strategies. Shear-punch coupons (N = 47 specimens) were extracted from right-parietal and frontal bones of three fresh-frozen-thawed human skulls. The specimens were kept as full through-thickness or segmented...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 22, 2021 Category: Materials Science Authors: Brown AD, Rafaels KA, Weerasooriya T Tags: J Mech Behav Biomed Mater Source Type: research

A new design of a multifunctional abutment to morse taper implant connection: Experimental mechanical analysis.
The objective of this study was to evaluate a new design of multifunctional abutment for Morse taper implant connections, relative to the retentive stability after the application of cyclic loads in cemented and screwed crowns. Multifunctional abutments with two different angulations in the seating portion of the crown were tested, forming 2 groups (n = 30 samples per group): Group Abut11, where Smart abutments with an angle of 11.42° were used; Group Abut5, where Ideale abutments with an angle of 5° were used. Fifteen samples from each group received cemented crowns (CC) and another fifteen screwed crown...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 22, 2021 Category: Materials Science Authors: Gehrke SA, Dedavid BA, de Oliveira Fernandes GV Tags: J Mech Behav Biomed Mater Source Type: research

Comparative Raman study on the molecular structure and IN VIVO wear of poly(methyl methacrylate)-based devices used as temporary knee prostheses: Effect of the antibiotic.
This study was aimed at comparatively investigating, on a molecular scale, two types of spacers from the same manufacturer (Spacer K and Vancogenx-space knee, Tecres, Italy), which differ for the added antibiotic (gentamicin sulphate in Spacer K and gentamicin sulphate + vancomycin hydrochloride in Vancogenx). Raman spectroscopy was used to gain more insights into the possible effects of the antibiotic on the spacer composition and polymer structure both in the new components and after in vivo use. Vancogenx was found to contain a lower residual MMA content than Spacer K (about 0.15% versus 0.4%). The former cont...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 21, 2021 Category: Materials Science Authors: Taddei P, Affatato S Tags: J Mech Behav Biomed Mater Source Type: research

3D-printed PEEK implant for mandibular defects repair - a new method.
This study aimed to develop a new functional repair method for mandibular defects combined with 3D-printed polyetheretherketone (PEEK) implant and the free vascularized fibula graft, and evaluated the service performance of the implant under whole masticatory motion. The design criteria and workflows of the mandibular reconstruction were established based on the requirements of safety, functionality, and shape consistency. Both the biomechanical behavior and the mechanobiological property of mandibular reconstruction under various masticatory motion were investigated by the finite element analysis. The maximum von Mises st...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 21, 2021 Category: Materials Science Authors: Kang J, Zhang J, Zheng J, Wang L, Li D, Liu S Tags: J Mech Behav Biomed Mater Source Type: research

Quasi-static analysis of hip cement spacers.
In this study, a validated Finite Element Modelling (FEM) was used to analyze the behavior of spacers. This FEM model uses a non-linear dynamic explicit integration to simulate the mechanical behavior of the spacer under quasi-static loading. In addition to this FEM, Extended Finite Element Method (XFEM) was also used to investigate the fracture behavior of the spacers reinforced with titanium, ceramic and stainless-steel spacer stems. The effect of the material on the performance of the reinforced spacers was also analyzed. The results showed that numerical modelling based on explicit finite element using ABAQUS/Explicit ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 20, 2021 Category: Materials Science Authors: Mallek A, Miloudi A, Khaldi M, Bouziane MM, Bouiadjra BB, Bougherara H, Gill RHS Tags: J Mech Behav Biomed Mater Source Type: research

Prediction of cross section fracture path of cortical bone through nanoindentation array.
Abstract Although great progresses in the fracture mechanisms and deformation behaviors of cortical bones have been achieved, the effective methods to predict the surface fracture path of cortical bones are still difficult. By using depth-sensing nanoindentation measurement technique, the hardness distribution map of cortical bones was obtained through nanoindentation array. Combined with the compressive tests under approximate in vivo environment and micro computed tomography (CT) analysis, the correlation between hardness distribution map and compressive fracture path on the cross section of cortical bone was es...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 20, 2021 Category: Materials Science Authors: Ma Z, Qiang Z, Zeng K, Xiao J, Zhou L, Zu L, Zhao H, Ren L Tags: J Mech Behav Biomed Mater Source Type: research

Alginate hydrogel: The influence of the hardening on the rheological behaviour.
Abstract Alginate based gels are widely adopted in many pharmaceutical and biomedical fields. The main rheological characteristics of the alginate-based gels are important design parameters for gel preparation. A new methodology for rheological tests on the alginate-based gels has been assessed in order to obtain reliable and reproducible results in terms of loss and storage moduli. The methodology accounts for the effect of morphology on the rheological properties. Reliable results can be achieved if the structure of the gel is preserved during the analysis, thus, the control of the load applied during the rheolo...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 19, 2021 Category: Materials Science Authors: Liparoti S, Speranza V, Marra F Tags: J Mech Behav Biomed Mater Source Type: research

A novel assessment of microstructural and mechanical behaviour of bilayer silica-reinforced nanocomposite hydrogels as a candidate for artificial cartilage.
Abstract The complex structure of healthy articular cartilage facilitates the joint withstanding the imposed pressures and retaining interstitial fluid to lessen stresses on its soft tissue, while easing the locomotion and minimising friction between cartilage mates. Avascular nature of this tissue results in unrecoverable damaged lesions and severe pain over time. Polymeric hydrogels are promising candidate materials for the replacement of the damaged cartilage. Hence, a tough bilayer nanocomposite acrylamide-acrylic acid hydrogel reinforced with silica nanoparticles (SNPs) was designed and synthesised. The mecha...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 18, 2021 Category: Materials Science Authors: Mostakhdemin M, Nand A, Ramezani M Tags: J Mech Behav Biomed Mater Source Type: research

Corrosion induced fracture of NiTi wires in simulated oral environments.
Abstract This work aims to assess the influence of corrosion on fracture of nickel titanium (NiTi) superelastic wires in physiological solutions (9 g/l NaCl) with and without addition of 1 g/l NaF. The electrochemical cell was coupled to a Hounsfield Tensiometer tensile machine commonly used for corrosion investigation of alloys under stress and strain. Corrosion tests were performed on unstrained and strained conditions up to 4% total strain. This strain limit corresponds to 50% of the total elongation achieved into the superelastic stress plateau of the alloy. All wire specimens were analyzed after tes...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 15, 2021 Category: Materials Science Authors: Kassab E, Gomes JADCP Tags: J Mech Behav Biomed Mater Source Type: research

UHMWPE / nanodiamond nanocomposites for orthopaedic applications: A novel sandwich configuration based approach.
Abstract Ultra high molecular weight polyethylene (UHMWPE) remains a primary choice of material for load bearing applications in total joint arthroplasty. Superior mechanical properties and wear resistance are unique to its performance. However, the addition of nanomaterials has improved its properties significantly. In the present study, a novel sandwich configuration has been considered to achieve unique surface and bulk properties specific to these sandwich composites. UHMWPE was reinforced at various loadings of 0.1, 0.3, 0.5, and 0.7 wt. % by surface modified Nano-diamond (ND). It is observed that the yo...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 13, 2021 Category: Materials Science Authors: Dalai N, Sreekanth PSR Tags: J Mech Behav Biomed Mater Source Type: research

Effects of implant buccal distance on peri-implant strain: A Micro-CT based finite element analysis.
Abstract Bone-implant mechanics is one of the factors that contribute to implant stability and success. In this work, voxel-based finite element models were built based on the micro-CT images of human cadaveric mandible specimens before and after implant placement. The computed results show high strain at the bone-implant contact locations and the buccal and lingual bone plates. The strain concentration in the thinner buccal plates was more substantial than that in the thicker lingual plates. The average values of maximum principal strain in the buccal and lingual ROIs were in good agreement with those measured us...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 13, 2021 Category: Materials Science Authors: Su K, Zhou Y, Hossaini-Zadeh M, Du J Tags: J Mech Behav Biomed Mater Source Type: research

Silica-filled methacrylic composites with extremely high compressive strength.
Abstract SYLOID® 244 has never been applied as a filler in composites with potential dental application. Therefore, the aim of research was to apply this silica in its unmodified and diazonium salt-modified forms in different mass ratios as fillers in light-cured methacrylic composites. The effectiveness of modification process was confirmed with the use of Raman spectroscopy. Methacrylic composites with the modified and unmodified SYLOID® 244, as well as unfilled resin as a control group were prepared. Their basic physicochemical properties, such as depth of cure, mass stability during incubation in salin...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 13, 2021 Category: Materials Science Authors: Sandomierski M, Buchwald Z, Buchwald T, Voelkel A Tags: J Mech Behav Biomed Mater Source Type: research

Hamstring muscles rupture under traction, peeling and shear lap tests: A biomechanical study in rabbits.
Abstract Lesions of the Musculotendinous Unit (MTU, i.e. tendon, myotendinous junction, muscle, aponeurosis and myoaponeurotic junction) are a common injury and a leading cause of functional impairment, long-term pain, and/or physical disability worldwide. Though a large effort has been devoted to macroscopic failure evaluation, these injuries suffer from a lack of knowledge of the underlying tissue-scale micro-mechanisms triggering such lesions. More specifically, there is a strong need for experimental data to better understand and quantify damage initiation and propagation on MTUs. The present study presents or...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 13, 2021 Category: Materials Science Authors: Pillet B, Badel P, Edouard P, Pierrat B Tags: J Mech Behav Biomed Mater Source Type: research

Epoxy based sandwich composite using three-dimensional integrally woven fabric as core strengthened with additional carbon face-sheets.
Abstract Sandwich composites are three-dimensional (3D) composite structures that offer higher stiffness with overall low density. However, they suffer from low strength; thus, not suited for load bearing applications. In this work, an attempt is made to develop a high strength lightweight sandwich composite suited for load-bearing applications. A sandwich composite based on 3D integrally woven fabric with thickness 3 mm as the core and strengthened with additional 2x2 twill woven carbon fabric face-sheets is reported. The samples were manufactured by wet hand lay co-lamination process using Araldite® LY ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 13, 2021 Category: Materials Science Authors: Balakumaran V, Alagirusamy R, Kalyanasundaram D Tags: J Mech Behav Biomed Mater Source Type: research

A finite element investigation on design parameters of bare and polymer-covered self-expanding wire braided stents.
This study represents the first experimentally-validated computational model for covered wire braided stent systems and has excellent potential to be used in future design of these devices for a range of applications. PMID: 33454463 [PubMed - as supplied by publisher] (Source: Journal of the Mechanical Behavior of Biomedical Materials)
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 7, 2021 Category: Materials Science Authors: McKenna CG, Vaughan TJ Tags: J Mech Behav Biomed Mater Source Type: research

It's worth cleaning - The examination of the female taper could identify a particular cause of trunnionosis at revision 16 years after total hip arthroplasty.
This report documents with advanced analysis of the retrievals a particular cause of trunnionosis in late failure of a small diameter MoM THR and illustrates the importance of cleaning of the taper when seating the head in THR. A 65-year-old patient was revised due to ARMD 16 years after small diameter MoM THR. Debridement and exchange of the inlay and the head had been performed through an anterior approach. While the cup and the outer surface of the head were accessible to direct analysis by an optical coordinate measuring machine, the female taper had to be analysed indirectly by measuring an imprint. Wear from the cup ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 6, 2021 Category: Materials Science Authors: Büchner M, Cook RB, Dommann-Scherrer C, Meier C, Dommann A, Wahl P Tags: J Mech Behav Biomed Mater Source Type: research

Load capacity of occlusal veneers of different restorative CAD/CAM materials under lateral static loading.
Abstract OBJECTIVE: The aim of this in vitro study was to analyze the failure of occlusal veneers made of three different restorative CAD/CAM materials under lateral static loading. MATERIALS AND METHODS: Sixty standardized semi-anatomical occlusal veneers were fabricated on natural lower molars from three different CAD/CAM materials: hybrid ceramic (Vita Enamic), lithium disilicate (IPS e. max CAD) and translucent zirconia (Bruxzir). The specimens were mechanically loaded by a custom-made device attached to a universal testing machine (MTS 858 Mini Bionix II, MN, USA). Static lateral loading was applied on t...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 6, 2021 Category: Materials Science Authors: Zamzam H, Olivares A, Fok A Tags: J Mech Behav Biomed Mater Source Type: research

Printability and mechanical performance of biomedical PDMS-PEEK composites developed for material extrusion.
In this study, for the first time, solvent-free biocompatible PDMS-PEEK composites (up to 30 wt% PEEK) were successfully characterised for material extrusion (ME) printing. Rheological analysis confirmed shear-thinning of all PDMS-PEEK composites under applied load (within the tolerances of the printer) and dominant storage moduli at rest (i.e. prints can self-support), considered highly desirable for ME-based printing. Attained rheological datasets were used to guide initial printability studies, which revealed finer track fidelity with rising fractional content of PEEK, at comparable print speed and displacement val...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 5, 2021 Category: Materials Science Authors: Smith JA, Li S, Mele E, Goulas A, Engstrøm D, Silberschmidt VV Tags: J Mech Behav Biomed Mater Source Type: research

Embedded sensing package for temporary bone cement spacers in infected total knee arthroplasty.
In this study a telemetric sensor system to integrate with a bone cement spacer and measure knee joint temperature was designed and evaluated. The sensor package precision, accuracy, hysteresis, and thermal equilibrium were empirically determined. Cadaveric testing was performed with the sensor package implanted inside the femoral notch alongside a pre-formed femoral and tibial bone cement spacer. The limb was tested though 30,000 cycles at 0.5 Hz under a 500 N load. Accuracy and precision of the sensing package were found to be ±0.24 °C and 0.09 °C respectively with negligible hysteresis...
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 1, 2021 Category: Materials Science Authors: Lavdas MK, Willing R, Lanting BA, Teeter MG Tags: J Mech Behav Biomed Mater Source Type: research

Tensile mechanical properties of the cervical, thoracic and lumbar porcine spinal meninges.
DISCUSSION: The variety of mechanical properties of the spinal meninges suggests that it cannot be regarded as a homogenous structure along the whole length of the spinal cord. PMID: 33395616 [PubMed - as supplied by publisher] (Source: Journal of the Mechanical Behavior of Biomedical Materials)
Source: Journal of the Mechanical Behavior of Biomedical Materials - January 1, 2021 Category: Materials Science Authors: Sudres P, Evin M, Wagnac E, Bailly N, Diotalevi L, Melot A, Arnoux PJ, Petit Y Tags: J Mech Behav Biomed Mater Source Type: research

Influence of polymerization pressure and post-cure treatment on conversion degree and viscoelastic properties of polymer infiltrated ceramic network.
This study aimed at determining an optimum polymerization pressure for Polymer Infiltrated Ceramic Network (PICN) blocks by characterizing the conversion degree (DC) and the viscoelastic properties of experimental PICN blocks polymerized at 90 °C under various high pressures followed or not by post-cure treatment (PC). Near infrared analysis and dynamic mechanical analysis were used to characterize DC and viscoelastic properties of sixteen PICN: one control (thermo-cured) and fifteen experimental groups (one thermo-cured followed by PC and fourteen high pressure polymerized PICN, in the range of 50-350 MPa wi...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 28, 2020 Category: Materials Science Authors: Pomès B, Behin P, Jordan L, Legoff S, Stoclet G, Richaud E, Nguyen JF Tags: J Mech Behav Biomed Mater Source Type: research

Evaluation of physico-mechanical properties and filler particles characterization of conventional, bulk-fill, and bioactive resin-based composites.
CONCLUSIONS: Monomer composition and fillers characteristics greatly influenced the physico-mechanical properties of the tested composites. PMID: 33383377 [PubMed - as supplied by publisher] (Source: Journal of the Mechanical Behavior of Biomedical Materials)
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 27, 2020 Category: Materials Science Authors: Gomes de Araújo-Neto V, Sebold M, Fernandes de Castro E, Feitosa VP, Giannini M Tags: J Mech Behav Biomed Mater Source Type: research

Fabrication and in-vitro characterization of a polymeric aortic valve for minimally invasive valve replacement.
In this study a polyurethane-based self-expandable tri-leaflets heart valve compatible with MIAVR procedure is proposed. The device is based on the development, fabrication and characterization of three different elements: the leaflets, the polymeric stent for supporting the leaflets, and the external metallic stent for anchoring the valve to the native aortic root. The polymeric stent and the valve leaflets were fabricated using a thermoplastic silicone-polycarbonate-urethane using 3D printing and spray technology while the external metallic stent was made in nickel titanium (Nitinol) to obtain a self-expandable valve aft...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 25, 2020 Category: Materials Science Authors: Cavallo A, Gasparotti E, Losi P, Foffa I, Al Kayal T, Vignali E, Celi S, Soldani G Tags: J Mech Behav Biomed Mater Source Type: research

Biopolymer surface modification of PLGA fibers enhances interfacial shear strength and supports immobilization of rhGDF-5 in fiber-reinforced brushite cement.
Abstract Incorporation of biodegradable poly(lactic-co-glycolic acid; PLGA) fibers into calcium phosphate cements (CPCs) has proven beneficial for their mechanical properties and the targeted delivery of bone morphogenetic proteins (BMPs). However, the deficiency of functional groups on the PLGA surface results in poor fiber-matrix interfacial strength (ISS), limiting the mechanical improvement, and insufficient surface charge to immobilize therapeutic amounts of BMPs. The present study therefore focused on the: i) functionalization of PLGA fibers using polyelectrolyte multilayers (PEMs) of biopolymers; ii) analys...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 23, 2020 Category: Materials Science Authors: Firkowska-Boden I, Adjiski R, Bautista AC, Borowski A, Matziolis G, Jandt KD, Kinne RW, Bossert J Tags: J Mech Behav Biomed Mater Source Type: research

Location- and layer-dependent biomechanical and microstructural characterisation of the porcine urinary bladder wall.
In this study, the load transfer mechanisms were not only associated with the wavy structure of muscular and mucosal layers, but also with the entire bladder wall microstructure. Contextually, an interplay between the mucosal and muscular layers could be identified. Therefore, depending on the region and direction, the mucosal layer exhibited a stiffer mechanical response to equi-biaxial loading than that offered by the muscular layer when deformed to stretch levels higher than λ=1.6 to λ=2.2. For smaller stretches, the mucosal layer evinces no significant mechanical reaction, while the muscular layer bears t...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 21, 2020 Category: Materials Science Authors: Trostorf R, Morales-Orcajo E, Siebert T, Böl M Tags: J Mech Behav Biomed Mater Source Type: research

Effect of TiF4 varnish after pre-treatment with proanthocyanidin or chlorhexidine on the progression of erosive dentin loss in the presence or absence of the demineralized organic matrix.
This study evaluated the protective effect of TiF4 varnish, after pre-treatment with proantocyanidin or chlorhexidine, on the progression of erosive dentin loss (EDL), under the presence or absence of the demineralized organic matrix (DOM). Bovine root dentin samples were eroded for 30 min (0.1% citric acid, pH 2.5) and the loss was measured by profilometry. Half of them were subjected to the DOM removal using collagenase for 4 days, while the other half remained immersed in water. The removal of DOM was checked by profilometry. Samples were divided into 24 groups (n = 15) according to the factors: 1- With o...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 19, 2020 Category: Materials Science Authors: Vertuan M, Souza BM, Mosquim V, Silva CV, Freitas PM, Borges AFS, Rios D, Magalhães AC, Honório HM Tags: J Mech Behav Biomed Mater Source Type: research

Prediction of local strength of ascending thoracic aortic aneurysms.
In this study, machine learning is applied to predict the local strength of ATAA tissues based on tension-strain data collected through in vitro inflation tests on tissue samples. Inputs to machine learning models are tension, strain, slope, and curvature values at two points on the low strain region of the tension-strain curve. The models are trained using data from locations where the tissue ruptured, and subsequently applied to data from intact sites to predict the local rupture strength. The predicted strengths are compared with the known strength at rupture sites as well as the highest tension the tissues experienced ...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 18, 2020 Category: Materials Science Authors: He X, Avril S, Lu J Tags: J Mech Behav Biomed Mater Source Type: research

Comparison of hardness and polishability of various occlusal splint materials.
Abstract OBJECTIVES: To measure polishability of occlusal splint materials manufactured by various methods. METHODS: Seven occlusal splint materials manufactured by four different methods - Heat cured (Vertex Rapid simplified Clear), CAD-milled (Ceramill a-splint), Vacuum-formed (Proform splint) and 3D-printed (Freeprint Ortho, KeySplint Soft, DentaClear and FreePrint Splint 2.0) were tested for gloss, roughness, and surface hardness and elastic modulus. For all groups, the tests were repeated with the materials polished with three different polishing burs, pumice and high shine. All polishing procedures were...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 17, 2020 Category: Materials Science Authors: Grymak A, Aarts JM, Ma S, Waddell JN, Eun Choi JJ Tags: J Mech Behav Biomed Mater Source Type: research

Viscoelastic model characterization of human cervical tissue by torsional waves.
Abstract The understanding of changes in the viscoelastic properties of cervical tissue during the gestation process is a challenging problem. In this work, we explore the importance of considering the multilayer nature (epithelial and connective layers) of human cervical tissue for characterizing the viscoelastic parameters from torsional waves. For this purpose, torsional wave propagations are simulated in three multilayer cervical tissue models (pure elastic, Kelvin-Voigt (KV) and Maxwell) using the finite difference time domain method. High-speed camera measurements have been carried out in tissue-mimicking ph...
Source: Journal of the Mechanical Behavior of Biomedical Materials - December 15, 2020 Category: Materials Science Authors: Callejas A, Melchor J, Faris IH, Rus G Tags: J Mech Behav Biomed Mater Source Type: research