Purpose: Poly(methyl methacrylate) (PMMA) is the most commonly used material in the production of dental prostheses, and its application is often accompanied by the formation of biofilm. The aim of this work was the preparation of a PMMA/gold nanoparticles (AuNps) composite to improve the antimicrobial properties of heat-polymerised PMMA. The AuNPs were synthesised from gold (III) acetate by Ultrasonic Spray Pyrolysis (USP).In the present study, flexural strength and elastic modulus were investigated, as well as thermal conductivity, density and hardness of the PMMA/AuNps` nanocomposite, with different concentrations of AuNps. Flexural strength and elastic modulus were measured using a three-point bending test, and surface hardness was evaluated using the Vickers hardness test. The thermal conductivity of the samples was measured using the Transient Plane Source (TPS) technique. Density was determined by the pycnometry procedure. Statistical analysis was conducted on the data obtained from the experiments.
Results: The flexural strength and elastic modulus of AuNps/PMMA nanocomposites decreased for all groups containing AuNps. Thermal conductivity and density increased in all groups containing AuNps compared to the control group, but it was not significant in all groups. Vickers hardness values increased significantly with an increase in AuNps` content, with the highest value 21.45 HV obtained at 0.74 wt% of AuNps. Statistical analysis was performed by means of the SPSS 19 software package.
Conclusions: Incorporation of AuNps into heat-polymerised PMMA resin led to decrease of the flexural strength and elastic modulus. At the same time, the density, thermal conductivity and hardness increased.
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http://dx.doi.org/10.2186/jpr.JPOR_2019_581 | DOI Listing |
Nanomaterials (Basel)
January 2025
Department of Conservative Dentistry, University Hospital, Ludwig-Maximilians-University, Goethestr. 70, D-80336 Munich, Germany.
Objective: It is hypothesized that the way nano- and micro-hybrid polymer-based composites are structured and cured impacts the way they respond to aging.
Material And Methods: A polymer-ceramic interpenetrating network composite (Vita Enamic/VE), an industrially polymerized (Brillinat CriosST/BC), and an in situ light-cured composite with discrete inorganic fillers (Admira Fusion5/AF5) were selected. Specimens (308) were either cut from CAD/CAM blocks (VE/BC) or condensed and cured in white polyoxymethylene molds (AF5) and subjected to four different aging conditions ( = 22): (a) 24 h storage in distilled water at 37 °C; (b) 24 h storage in distilled water at 37 °C followed by thermal cycling for 10,000 cycles 5/55 °C (TC); (c) TC followed by storage in a 75% ethanol-water solution; and (d) TC followed by a 3-week demineralization/remineralization cycling.
J Contemp Dent Pract
September 2024
Department of Prosthodontics, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Sangli, Maharashtra, India, ORCID: https://orcid.org/0000-0002-6661-0931.
Aim: The aim of this systematic review was to evaluate the effect of build orientation on the mechanical and physical properties of additively manufactured resin using digital light processing (DLP).
Background: The properties of 3D-printed materials are influenced by various factors, including the type of additive manufacturing (AM) system and build orientation. There is a scarcity of literature on the effect of build orientation on the mechanical and physical properties of additively manufactured resins using DLP technology in dentistry.
Sci Rep
January 2025
School of Civil Engineering, Vellore Institute of Technology, Chennai, Tamil Nadu, 600127, India.
The carbon footprint associated with cement production, coupled with depletion of natural resources and climate change, underscores the need for sustainable alternatives. This study explores the effect of metakaolin (MK) and nano-silica (NS) on concrete's engineering performance and environmental impact. Initially, compressive, tensile, and flexural strength tests, along with durability assessments like water absorption, sorptivity, rapid chloride permeability, and resistance to acid and sulphate attacks, were conducted.
View Article and Find Full Text PDFSci Rep
January 2025
Institute of the Malay World and Civilisation (ATMA), Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia.
The adoption of pultruded glass fibre-reinforced polymer (pGFRP) composites as a substitute for traditional wooden cross-arms in high transmission towers represents a relatively novel approach. These materials were selected for their high strength-to-weight ratio and lightweight properties. Despite various studies focusing on structures improvement, there still have a significant gap in understanding the deformation characteristics of full-scale cross-arms under actual operational loads.
View Article and Find Full Text PDFJ Prosthet Dent
January 2025
Associate Professor, Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Switzerland; and Adjunct Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University, Columbus, OH.
Statement Of Problem: Acrylic denture base resins are subject to colonization by oral and nonoral bacteria, contributing to the onset of denture stomatitis. However, how the addition of antimicrobial substances affects the mechanical and optical properties of additively manufactured denture base resin remains unclear.
Purpose: The purpose of this in vitro study was to investigate the surface roughness, color stainability, and flexural strength of antimicrobial-modified, additively manufactured polymethyl methacrylate (PMMA) denture base resin in tooth and gingiva colors.
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