Indentation size effect (ISE) and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10–19.6 N to determine the load influence on the measured hardness. For the IS-measured fracture toughness, the load ranged from 1.96–19

The success of large bone defect repair with tissue engineering technology depends mainly on angiogenesis and osteogenesis. In this study, we prepared poly-caprolactone/nano-hydroxyapatite/beta-calcium phosphate (PCL/nHA/β-TCP) composite scaffolds loaded with poly-(lactic-co-glycolic acid)/nano-hydroxyapatite/collagen/heparin sodium (PLGA/nHA/Col/HS) nanofiber small vascular stent by electrospinning

Reliable fracture diagnosis monitoring and analyzing low-frequency transverse vibration data can be achieved through an in-depth understanding of the physical interactions between wave propagation and boundary conditions. The present study aims to investigate the effects of the boundary conditions on the low-frequency structural vibrations of bones. Time–frequency domain analysis of transverse vibration

Mastication is the motor task with the highest muscle activations of the jaw region, potentially leading to high temporomandibular joint (TMJ) loading. Since increased loading of the TMJ is associated with temporomandibular disorders (TMD), TMJ mechanics during chewing has potential clinical relevance in TMD treatment. TMD self-management guidelines suggest eating soft and small pieces of food to reduce

Snails offer successful attachment and locomotion on horizontal and vertical surfaces, and have inspired extensive research to develop artificial adhesives. Here, we experimentally investigate the response mechanisms of snails to mechanical signals (pull-off force and crawling angle), then propose a way to design a bioinspired sucker, and theoretically analysis its application in vacuum suction. The

In vitro real-time replication of three-dimensional, time-varying load profiles acting on human bones during physical activity can advance bone and implant testing protocols. This study aimed to develop a novel protocol for applying the three-dimensional, time-varying hip contact force while walking to a human femur specimen. The target force profile was obtained from the literature. A proximal femur

3D image-based finite element (FE) and bone volume fraction (BV/TV)/fabric tensor modeling techniques are currently used to determine the apparent stiffness tensor of trabecular bone for assessing its anisotropic elastic behavior. Inspired by the recent success of deep learning (DL) techniques, we hypothesized that DL modeling techniques could be used to predict the apparent stiffness tensor of trabecular

The response of fibrous soft tissues undergoing torsional deformations is a topic of current interest. Such deformations are common in ligaments and tendons and are also of particular interest in cardiac mechanics. The problem of torsion superimposed on extension of incompressible hyperelastic solid circular cylinders is a classic problem of nonlinear elasticity that has been considered by many authors

Stiff biological materials (SBMs), such as nacre and bone, are composites that display remarkable toughness enhancements over their primary constituents, which are brittle minerals. These enhancements are thought to be a consequence of different mechanisms made possible by the SBMs’ internal lamellar architecture. One such mechanism is the Cook–Gordon (crack-arrest-and-reinitiation) mechanism, whose

The present paper aims at developing an integrated experimental/computational approach towards the design of shape memory devices fabricated by hot-processing with potential for use as gastroretentive drug delivery systems (DDSs) and for personalized therapy if 4D printing is involved. The approach was tested on a plasticized poly(vinyl alcohol) (PVA) of pharmaceutical grade, with a glass transition

Objectives To measure the effect of placement of glass fibre mesh on the flexural strength and load bearing capacity of repaired polymethylmethacrylate (PMMA) denture base resin. Materials and methods A total of 150 heat-polymerised acrylic resin specimens were fabricated with dimensions of 5 × 30 × 50 mm for flexural strength testing. Specimens were divided into 5 groups according to repair width

In this work, molecular dynamics simulations are conducted to investigate the structural and mechanical properties of dental materials, i.e., the silica nanorod reinforced Bis-GMA/TEGDMA resin composite. The effects of loading content and size of the silica nanorods on the composite stiffness were performed by examining resin chain conformation, hydrogen bonds and matrix/filler binding energy. It is

Aim The aim of this in vitro study was to assess the mechanical properties of five commercially available subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) milled splint materials, as well as to compare them with conventional heat-polymerized and autopolymerizing resins used in the construction of conventional splints. Material and methods Five CAD-CAM milled (ProArt CAD

Objectives Since restored teeth are subject to more damages than intact teeth, investigating their fracture behavior is important. However, so far, improvement of the debonding behavior of the restoration and fracture of restored teeth considering the geometry of the restoration and different restorative materials has remained understudied. The aim of this paper is to numerically and experimentally

This study evaluated the effect of grinding and polishing the inner surface of monolithic discs made of zirconia polycrystals (ZR) and lithium disilicate glass-ceramic (LD) on the load-bearing capacity under fatigue of the restorations bonded onto a dentin analogue material (epoxy resin). ZR and LD ceramic discs (10 mm in diameter, 1 mm thickness) were produced and randomly allocated into 10 groups

As a viscous high-performance submucosal injection material (SIM) used in endoscopic submucosal dissection (ESD), sodium alginate-based SIM (SA-SIM) was recently introduced as high-performance SIM equivalent to sodium hyaluronate-based SIM (HA-SIM) in Japan. However, a comprehensive, detailed comparison of SA and HA is yet to be performed. In this study, we precisely measured the viscoelastic properties

Distal phalanges in bat wings have been hypothesized to be cartilaginous to allow for flight. We provide new evidence on how bat wing development might facilitate flight though protein-based regulation of bone mineralization and lead to more deflection at phalanx than humerus. Between Pteropus poliocephalus and Pteropus hypomelanus, two large bat species, we detected 112 proteins including 11 associated

The effectiveness of dimple surface texturing via picosecond pulsed laser processing for reducing wear loss was investigated using two types of titanium alloys, β-type Ti–29Nb–13Ta-4.6Zr (TNTZ) and α+β-type Ti–6Al–4V ELI (Ti64). The two alloys showed different modes of wear against zirconia. As the sliding distance increased, the wear loss was observed to increase for Ti64, but not necessarily for

Background Novel technologies for management and reconstruction of complex bony defects regarding both function and facial appearance are interestingly used in maxillofacial surgery. In the current study, we demonstrated reconstruction of a bilateral ramus-condyle unit (RCU) defect while preserving both condyles by a novel designed titanium prosthesis using virtual surgical planning (VSP), computer-aided

Epithelial keratin, a type of intermediate filament (IF) protein, is one of the key components in maintaining the stability of the cell nucleus in the epidermis of the skin, the largest organ in the human body. It absorbs water and withstands external pressure, affecting the structural stability and mechanical properties of the skin. Epidermolysis bullosa simplex (EBS) is a rare genetic skin disease

An unresolved challenge in osteoarthritis research is characterising the localised intra-tissue mechanical response of articular cartilage. The aim of this study was to explore whether laboratory micro-computed tomography (micro-CT) and digital volume correlation (DVC) permit non-destructive quantification of three-dimensional (3D) strain fields in human articular cartilage. Human articular cartilage

An early health technology assessment (HTA) study was performed to assess the need for developing a new bioabsorbable implant for the treatment of specific orthopedic injuries. The Anterior Cruciate Ligament Reconstruction (ACLR) procedure was selected based on the need and potential impact of bioabsorbable implants in the treatment of ACL injuries. The economic model considers the possible health

The mechanical properties of normal soft tissues, including breast tissue, have been of interest to the biomedical research community as there are many clinical and industrial applications that can benefit from quantitative information characterizing such properties. For instance, computer assisted surgery planning, elastography for breast cancer diagnosis, and bra design can all involve biomechanical

Objective The aim of the study was to determine the effects of ultra-fast (3 s) light-curing on the viscoelastic behaviour at clinically relevant frequencies, and cell toxicity, in a resin-based composite (RBC) with reversible addition-fragmentation-chain transfer (RAFT) mediated polymerization. Methods Three different protocols were used to cure cylindrical samples (height = 4 mm, ϴ = 5 mm), including

New fabrication methods and lubrication materials must be developed to improve the lubrication performance of artificial joints and increase the lubrication duration. Herein, a novel polyvinyl alcohol/polyethylene glycol/graphene oxide (PVA/PEG/GO) hydrogel was prepared by a physical cross-linking method, and then the hydrogel and its sustained-release solution were used as lubricant for friction evaluation

Bone is a biological tissue with unique mechanical properties, owing to a complex hierarchical structure ranging from the nanoscale up to the macroscale. To better understand bone mechanics, investigation of mechanical properties of all structural elements at every hierarchical level and how they interact is necessary. Testing of bone structures at the lower microscale, e.g. bone lamellae has been

Osteoarthritis is a whole joint disease with cartilage degeneration being an important manifestation. Tissue engineering treatment is a solution for repairing cartilage defects by implantation of chondrocyte-laden hydrogel constructs within the defect. In silico models have recently been introduced to simulate and optimize the design of these constructs. These models require accurate knowledge on the

As a predominantly lithium-metasilicate-containing glass-ceramic, Obsidian® (Glidewell Laboratories, USA) has a peculiar composition and microstructure among other dental lithium silicates, warranting an evaluation of the crystallization process to establish relationships between microstructural evolution and mechanical properties. Blocks of the pre-crystallized material were processed into slices

This study evaluated the influence of surface treatments of resin composite substrate on the fatigue behavior of adhesively cemented lithium disilicate glass-ceramic simplified restorations. CAD/CAM lithium disilicate ceramic blocks were shaped into discs (N = 60, Ø = 10 mm; thickness = 1.0 mm). Resin composite discs (N = 60, Ø = 10 mm, thickness = 2 mm) were allocated into four groups considering

Soft tissues in the hip region, which are typically considered the natural shock-absorbers during falls, attenuate the applied forces to the underlying hard tissue. The soft tissue thickness is, therefore, a significant parameter in the force attenuation. Another factor that could affect the assessment of the force attenuation in numerical simulations is the choice of constitutive model and material

Antiresorptives such as bisphosphonates (BP) and denosumab are commonly used osteoporosis treatments that are effective in preventing osteoporotic fractures by suppressing bone turnover. Although these treatments reduce fracture risk, their long-term use has been associated with atypical femoral fracture (AFF), a rare potential side effect. Despite its rare occurrence, AFF has had a disproportionately

The contribution of the proteoglycan to the strain-rate-dependent mechanical behaviour of cartilage tissues has been suggested to decrease with an increase in the strain-rate. On the other hand, the contribution from the collagen network has been suggested to increase as the strain-rate increases. These conclusions are drawn mainly based on numerical studies conducted on high-load-bearing knee cartilage

Purpose Proper understanding of skin biomechanics, viscoelasticity and investigation of skin tension vectors is necessary to find optimal incision lines. Great tension across a healing wound after any surgical procedure might lead to forming hypertrophic scars. The aim of the study was to investigate tension lines in volar forearm skin in young males and females, in order to ensure best incision line

Growth-preserving spinal surgery suffer from high complications rate. A recent bipolar instrumentation using two anchoring points (thoracic and pelvic) showed lower rates, but its biomechanical behaviour has not been characterised yet. The aim of this work was to combine in vitro and in vivo data to improve and validate a finite element model (FEM) of the spine, and to apply it to compare bipolar and

Biomedical Co–29Cr–6Mo alloy is one of the alloys that are suitable for laser powder bed fusion (LPBF) additive manufacturing and as an implant material is often used in situations of critical and cyclic loading. Thus, fatigue crack growth (FCG) behaviour and resistance of the alloy processed by LPBF are an important consideration for dental and orthopaedic applications. In this study, FCG testing

Particulate reinforcement of polymeric matrices is a powerful technique for tailoring the mechanical and degradation properties of bioresorbable implant materials. Dispersion of inorganic particles is critical to achieving optimal properties, however established techniques such as twin-screw extrusion or solvent casting can have significant drawbacks including excessive thermal degradation or particle

Osteocytes are capable of remodeling their perilacunar bone matrix, which causes considerable variations in the shape and size of their lacunae. If these variations in lacunar morphology cause changes in the mechanical environment of the osteocytes, in particular local strains, they would subsequently affect bone mechanotransduction, since osteocytes are likely able to directly sense these strains