Vickers

AIM: Different remineralizing pretreatments Casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF), tricalcium phosphate fluoride (TCP-F), self-assembling peptide (SAP) P11-4 and 10% Nanohydroxyapatite (nHA) gel activation via invisible infrared light on the dentin microhardness (MH) and micro shear bond strength (µSBS) of composite restoration. METHODS: Seventy-five human molar teeth were collected and the dentinal surface of all the samples was exposed to different demineralizing solutions...

Purpose This study evaluated the color alterations, flexural strength and microhardness properties of two different 3D-printed permanent crown resins. Materials and Methods Samples were produced from two different 3D Print permanent crown resins: Group 1 (Saremco Crowntec; Saremco, Switzerland), Group 2 (P-crown Version 2; Senertek, Turkey). Color changes (ΔE values), flexural strenght and vickers hardness number of the samples were calculated. Data were analyzed with Shapiro-Wilk normality test, Independent-t test, and Mann Whitney-U tests...

Electroless nickel plating is a suitable technology for the hydrogen industry because electroless nickel can be mass-produced at a low cost. Investigating in a complex environment where hydrogen permeation and friction/wear work simultaneously is necessary to apply it to hydrogen valves for hydrogen fuel cell vehicles. In this research, the effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel (SUM 24L) were investigated. Due to the inherent characteristics of electroless nickel plating, the damage (cracks and delamination of grain) and micro-particles by hydrogen permeation were clearly observed at the grain boundaries and triple junctions...

A 63-year-old woman presented with hypokalemia, hypertension, weight gain, limb edema, and tremors. She was diagnosed with Cushing syndrome, with a 24-hour urine cortisol level of 41,013 nmol/day. Investigations revealed a grade 2 pancreatic neuroendocrine tumor with extensive hepatic metastases. Owing to excessive adrenocorticotropic hormone production from her disease, her hypercortisolemia and Cushing symptoms worsened despite ketoconazole, somatostatin analogs, and right liver lobe chemoembolization. Stereotactic body radiotherapy (SBRT) at a dose of 39 Gy in three fractions was administered to her bilateral adrenal glands in the hope of reducing her cortisol levels and improving her symptoms...

OBJECTIVES: Dental erosion in patients with gastroesophageal reflux disease (GERD) is a current and frequent condition that may compromise the mechanical properties and clinical durability of resin-based composites (RBCs). This study assessed the mechanical properties of conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs subsequent to simulated gastric acid aging. MATERIALS AND METHOD: Three conventional and three CAD/CAM composites were assessed...

No abstract text is available yet for this article.

This study presents the phase analysis, microstructural characteristics, and mechanical property evaluation of the as-cast and quenched Ti-15Mo-xFe alloys with high iron content ranging from 4 to 12 weight percent. All the four alloys were produced in a vacuum-arc melting furnace. Heat treatment in the form of solution treatment was performed in a muffle furnace at a temperature of 1100 °C, with 1-h holding time and the samples were rapidly quenched in ice-brine. X-ray diffractometer (XRD) was used to analyses the phases present in each alloy whereas the optical microscope (OM) was employed to track the microstructural evolution and percentage porosity...

PURPOSE: The purpose of the present in vitro study is to investigate and compare the remineralising potential of Moringa Oleifera extract, eggshell, and sodium fluoride varnish on microhardness of artificially demineralised enamel of primary teeth with biomimetic minimally invasive approach following the world paradigm shift towards natural products in paediatric dentistry. MATERIAL AND METHODS: Sample size included 44 primary molars. The mineral content and surface microhardness of all specimens were initially assessed using energy dispersive x-ray examination (EDX) and Vickers microhardness...

OBJECTIVES: This study aimed to assess the effect of a nano-hydroxyapatite (nano-HA) toothpaste on erosive enamel lesions of third molars induced by exposure to orange juice. MATERIALS AND METHODS: In this in vitro , experimental study, the microhardness of 24 sound-extracted third molars was measured by a Vickers tester. The teeth were then randomly assigned to three groups ( n = 8) of nano-HA toothpaste (Pharmed), 1.23% sodium fluoride gel, and artificial saliva...

Due to their amorphous structure, metallic glasses exhibit remarkable properties such as high strength, hardness, and elastic strain limit. Conversely, they also exhibit high susceptibility to brittle fracture, making them less qualified for the use as monolithic structural components. Therefore, they may be preferably used as the reinforcing phase in hybrid materials combined with ductile matrix materials. Especially metal matrix composites with interpenetrating structures are suitable. This requires an open-porous structure of the metallic glass...

Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear...

Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia...

BACKGROUND: Nano-silver fluoride (NSF) has been introduced to improve enamel lesions. The effective use of varnishes is important in the prevention of dental caries. OBJECTIVES: The study aimed to compare the effect of conventional sodium fluoride varnish with the same varnish containing 1% and 2% silver nanoparticles (AgNP) on the surface microhardness of enamel. MATERIAL AND METHODS: The baseline surface microhardness of 40 premolar teeth was measured using a Vickers microhardness tester...

BACKGROUND AND OBJECTIVES: Expanding outpatient surgery to the increasing number of procedures and patient populations warrants continuous evaluation of postoperative outcomes to ensure the best care and safety. We describe adverse postoperative outcomes and transfer rates related to anesthesia in a large sample of patients who underwent same-day cancer surgery at a freestanding ambulatory surgery center. METHODS: Between January 2017 and June 2021, 3361 cancer surgeries, including breast and plastic, head and neck, gynecology, and urology, were performed...

Background This study aimed to evaluate and compare the abrasive and erosive wear resistance of Cention N and titanium dioxide (TiO2 ) nanoparticle-enriched Cention N after three years of brushing simulation. Methodology A total of 48 freshly extracted mandibular molars were mounted in acrylic blocks and divided into two groups of 24 molars based on the type of restorative material used to restore them. Cavities of a standardized size were prepared. Group A was restored with Cention N, and group B was restored with 5% TiO2 -enriched Cention N...

Advancements in cochlear implants (CIs) have led to a significant increase in bilateral CI users, especially among children. Yet, most bilateral CI users do not fully achieve the intended binaural benefit due to potential limitations in signal processing and/or surgical implant positioning. One crucial auditory cue that normal hearing (NH) listeners can benefit from is the interaural time difference (ITD), i.e ., the time difference between the arrival of a sound at two ears. The ITD sensitivity is thought to be heavily relying on the effective utilization of temporal fine structure (very rapid oscillations in sound)...

No abstract text is available yet for this article.

Materials from green resources boast a low carbon footprint, forming the foundation of the circular economy approach in materials science. Thus, in this study, waste poly(ethylene terephthalate) (PET) was subjected to depolymerization using propylene glycol (PG), and subsequent polycondensation with bio-based maleic anhydride (MA) produced unsaturated polyester resin (b-UPR). Bio-derived acryloyl-modified Kraft lignin (Kf L-A) served as a vinyl reactive filler in the b-UPR matrix to create b-UPR/Kf L-A composites...

This work has studied the co-addition of Sc and Zr elements into the Al-1.75wt%Fe-1.25wt%Ni eutectic alloy. The changes in the microstructure, electrical conductivity, and Vickers hardness of the Al-1.75wt%Fe-1.25wt%Ni-0.2wt%Sc-0.2wt%Zr alloy during heat treatment were studied. The results showed that two-step aging can effectively improve the aging response of the alloy over the single-step aging method. This was ascribed to the minimization of the diffusion difference between Sc and Zr elements. Furthermore, the homogenization treatment can also improve the aging response of the alloy by alleviating the uneven distribution of Sc and Zr...

Oxide Dispersion Strengthened (ODS) ferritic steels are promising materials for the nuclear power sector. This paper presents the results of a study on the sintering process using the Spark Plasma Sintering (SPS) technique, focusing on ODS ferritic steel powders with different contents (0.3 and 0.6 vol.%) of Y2 O3 . The novelty lies in the analysis of the effect of pre-annealing treatment on powders previously prepared by mechanical alloying on the microstructure, mechanical, and thermal properties of the sinters...