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Slattery Shepherd posted an update 7 hours, 37 minutes ago
ovided comparable fracture forces. Wear was comparable between zirconia systems and lower in comparison to lithiumdisilicate or enamel.Structural repair of soft tissue for regenerative therapies can be advanced by developing biocompatible and bioresorbable materials with mechanical properties similar to the tissue targeted for therapy. Developing new materials modeling soft tissue mechanics can mitigate many limitations of material based therapies, specifically concerning the mechanical stress and deformation the material imposes on surrounding tissue structures. However, many elastomeric materials used in soft tissue repair lack the ability to be delivered through minimally invasive surgical (MIS) or transcatheter routes and require open surgical approaches for placement and application. We have developed a biocompatible and fully biodegradable shape memory elastomer, poly-(glycerol dodecanedioate) (PGD), which fulfills the requirements for hyperelasticity and exhibits shape memory behavior to serve as a novel substrate material for regenerative therapy in minimally invasive clinical procedures. Our previous work demonstrated control over t. OSMI-4 datasheet Incorporating 2 ply and 4 ply sheets and 0.5 wt% particulates into PGD decreased the fixity and recovery of composite materials compared to controls (p less then 0.01). Nonlinear modeling of stress strain curves under uniaxial tension demonstrated tunability of PGD-SIS composite materials to model various nonlinear soft tissues. These findings support the use of shape memory PGD-SIS composite materials towards the design of implantable devices for a variety of soft tissue regeneration applications by minimally invasive surgery.Forty percent of patients with a spinal cord injury acquire a pressure ulcer during rehabilitation, and sixty percent of individuals in elderly care facilities have at least one pressure ulcer upon admittance. A commonality between those populations is the increased amount of time they spend in the seated position. The loading on the buttocks and thighs while in the seated position has been cited as a risk factor for pressure ulcer formation, especially for wheelchair users. Finite element models provide a tool with which to evaluate the internal tissue stresses, but they are reliant upon accurate material properties for the soft tissue. Thus the goals of this research were to determine and compare the material properties of the soft tissue in the thigh and buttock regions in the seated, quadruped (a universally accessible position with the knee and hip articulations similar to the seated position), and prone positions. A custom indenter was designed to collect force and deflection data for the buttocks/proximal thigh, middle thigh, and distal thigh regions of twenty able-bodied individuals. The force and deflection data were converted into stress and stretch data, which were used to obtain parameters from an Ogden material model. Our results indicated that the prone position yielded significantly stiffer tissue properties than in the seated and quadruped positions for both males and females, meaning that position should be taken into account when obtaining material properties that are input into finite element models. Realistic material properties of the soft tissue will lead to better understanding of tissue injury risk.This study evaluated the effect of different firing processes (without firing, additional crystallization and glaze firing) and thermal-cycling (with or without) on the fatigue behavior of simplified zirconia-lithium silicate (ZLS) glass ceramic restorations cemented to a dentin-like material. Materials and Methods. One hundred twenty-nine (129) discs (diameter = 12 mm and thickness = 1.2 mm) of ZLS (Celtra Duo, Dentsply Sirona) and fiber-reinforced epoxy resin (diameter = 12 mm and thickness = 2.3 mm) were produced and tested under fatigue according to 2 study factors a firing protocol with 3 levels (without firing, additional crystallization and glaze firing) and thermocycling of 2 levels (absence/presence), composing 6 study groups. Ceramic and epoxy resin discs had their surfaces treated and adhesive cementation was performed (Multilink N, Ivoclar). Half of the samples were immediately tested; the other half were subjected to thermal-cycling (10,000 cycles in water; 5-55 °C). The staircase method determined the fatigue failure load (100,000 cycles at a frequency of 20 Hz). The fatigue data (in N) were submitted to 2-way ANOVA and Bonferroni test (p less then 0.05). Fractographic analyses were also carried out. Thermocycling decreased the fatigue failure load (FFL) of all groups when compared to those without aging. Bonferroni’s test indicated that the groups with crystallization/glazing process behaved better in terms of FFL than those without firing in the same storage condition. All the samples had radial cracks and all fractures originated from defects on the cementation surface of the ceramic discs. Crystallization and glaze firing had a positive effect on the fatigue failure load of adhesively cemented ZLS glass ceramic compared to the group without crystallization firing, in both storage conditions (with or without thermocycling).This study evaluated the distinct conditioning effect of the intaglio surface of bonded fully-stabilized zirconia (FSZ) simplified restorations on the mechanical fatigue behavior of the set prior to and after aging. Ceramic disc shaped specimens (Ø= 10 mm and 1 mm thick) were randomly allocated into 14 groups considering “surface treatments” (Ctrl no-treatment; PM universal primer; GLZ low-fusing porcelain glaze; SNF 5 nm SiO2 nanofilm deposition; AlOx air-abrasion with aluminum oxide; SiC air-abrasion with silica-coated aluminum oxide; 7%Si air-abrasion with 7% silica-coated aluminum oxide); and “aging” (baseline 24 h at 37 °C in water; or aged 90 days at 37 °C in water + 12,000 thermal cycles). The discs were treated, luted with resin cement onto the dentin analog, subjected to aging or not, and then tested under a step-stress fatigue test at 20 Hz, 10,000 cycles/step, step-size of 100N starting at 200N, and proceeding until failure detection. Fractographic, topographic, surface roughness, contact angle, and atomic force microscopy analyzes were performed.