Measure of microhardness, fracture toughness and flexural strength of N-vinylcaprolactam (NVC)-containing glass-ionomer dental cements.
Summary of "Measure of microhardness, fracture toughness and flexural strength of N-vinylcaprolactam (NVC)-containing glass-ionomer dental cements."
To investigate the effects of N-vinylcaprolactam (NVC)-containing terpolymers on the fracture toughness, microhardness, and flexural strength of conventional glass-ionomer cements (GIC).
The terpolymer of acrylic acid (AA)-itaconic acid (IA)-N-vinylcaprolactam (NVC) with 8:1:1 (
NVC) molar ratio was synthesized by free radical polymerization and characterized using (1)H NMR and FTIR. Experimental GIC samples were made from a 50% solution of the synthesized terpolymer with Fuji IX powder in a 3.6:1 P/L ratio. Specimens were mixed and fabricated at room temperature. Plane strain fracture toughness (K(Ic)) was measured in accordance with ASTM Standard 399-05. Vickers hardness was determined using a microhardness tester. Flexural strength was measured using samples with dimensions of 2mm×2mm×20mm. For all mechanical property tests, specimens were first conditioned in distilled water at 37°C for 1 day or 1 week. Fracture toughness and flexural strength tests were conducted on a screw-driven universal testing machine using a crosshead speed of 0.5mm/min. Values of mechanical properties for the experimental GIC were compared with the control group (Fuji IX GIC), using one-way ANOVA and the Tukey multiple range test at α=0.05.
The NVC-modified GIC exhibited significantly higher fracture toughness compared to the commercially available Fuji IX GIC, along with higher mean values of flexural strength and Vickers hardness, which were not significantly different.
It was concluded that NVC-containing polymers are capable of enhancing clinically relevant properties for GICs. This new modified glass-ionomer is a promising restorative dental material.
Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA.
This article was published in the following journal.
Name: Dental materials : official publication of the Academy of Dental Materials
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20851458
- DOI: http://dx.doi.org/10.1016/j.dental.2010.08.002
This study assessed the cross-sectional Knoop microhardness and flexural strength of root dentin exposed to different surface treatments with chemical agents after biomechanical preparation. Root cana...
We report the comparative in-situ fracture toughness testing on single-edge V/U-notched multilayer graphenes and boronitrenes in a high-resolution transmission electron microscope (HRTEM). The nanostr...
Abstract Objective. This study investigated the influence of water sorption on certain mechanical properties of injection-molded thermoplastic denture base resins. Materials and methods. Six thermopla...
Ideal implant-cement or implant-bone interfaces are required for implant fixation and the filling of tissue defects created by disease. Micron- to nanosize osseointegrated features, such as surface ro...
High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application o...
The purpose of this study is to examine the influence of intensive strength training of the the fractured leg in patients with hip fracture, during admittance in an acute orthopedic ward. ...
Patients who have suffered a first hip fracture have a higher risk of falling and sustaining another hip fracture compared with age-matched adults who did not fracture. Although exercise i...
This project will assess the effectiveness of a novel approach involving patient education and strength training to improve functional recovery after a hip fracture. Participants will be r...
Hip fractures mostly occur in elderly people with low bone strength. Bone strength is determined by bone mineral density (BMD), bone turnover, microarchitectural and geometrical properties...
This is a randomized, controlled; single-blind parallel group trial carried out with hip fracture patients, starting at 12 weeks post fracture. Patients were approached during their acute ...
Medical and Biotech [MESH] Definitions
Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.
A measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.
Implantable fracture fixation devices attached to bone fragments with screws to bridge the fracture gap and shield the fracture site from stress as bone heals. (UMDNS, 1999)
The internal resistance of a material to moving some parts of it parallel to a fixed plane, in contrast to stretching (TENSILE STRENGTH) or compression (COMPRESSIVE STRENGTH). Ionic crystals are brittle because, when subjected to shear, ions of the same charge are brought next to each other, which causes repulsion.
Fracture in the proximal half of the shaft of the ulna, with dislocation of the head of the radius.