This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.
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http://dx.doi.org/10.1590/s0103-64402009000400012 | DOI Listing |
J Prosthet Dent
November 2024
Professor, Department of Dentistry, University of Brasilia (UnB), Brasilia, Federal District, Brazil. Electronic address:
Statement Of Problem: With advancements in digital technologies, the digital workflow has revolutionized the fabrication of occlusal devices through additive methods using 3-dimensional (3D) printing. However, an established protocol for polishing 3D printed occlusal devices is lacking, despite this step being crucial for minimizing surface porosity, material fatigue and preventing bacterial plaque accumulation, thereby contributing to device longevity.
Purpose: The purpose of this in vitro study was to evaluate the impact of polishing systems on the surface roughness and Vickers microhardness of heat-polymerizing acrylic resin and 3D printing resins used for occlusal devices.
J Prosthet Dent
June 2024
Professor and Director of Biomaterials Research, Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, Tenn. Electronic address:
Statement Of Problem: New denture base acrylic resins have been introduced that are specifically formulated for microwave polymerization. Microwave polymerization is a time-efficient procedure, but few studies have evaluated how these new acrylic resin formulations compare with conventionally processed acrylic resins.
Purpose: The purpose of this in vitro study was to compare the stiffness and strength of denture base acrylic resins formulated for microwave polymerization with conventionally processed acrylic resin.
Clin Oral Investig
December 2023
Division of Prosthodontics, Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande Do Sul (UFRGS), Rua Ramiro Barcelos, 2492, Porto Alegre, Rio Grande do Sul, Brazil.
Objective: This study aimed to investigate changes in the surface characteristics of two denture resins when disinfected with a vinegar-hydrogen peroxide (VHP) mixture.
Materials And Methods: Microwave-polymerized or 3D printed acrylic resin disks were immersed for 900 min (simulating 90 daily uses) in the following solutions (N = 10): water; 0.5% sodium hypochlorite; hydrogen peroxide and water dilution (1:1 ratio); vinegar and water dilution (1:1 ratio); and VHP mixture.
Dent Mater J
March 2023
Department of Prosthodontics, Faculty of Dentistry, Bursa Uludağ University.
This study aimed to evaluate the hardness, roughness, and color stability of heat- and microwave-polymerized polymethyl methacrylate (PMMA), polyamide, and CAD-CAM PMMA resins when exposed to cigarette smoke (CS) and immersed in a denture cleanser (DC). Specimens of each resins were divided into four subgroups (n=10). The DC and CS+DC specimens were immersed in a DC; the CS and CS+DC specimens were exposed to CS; and the control (C) specimens were kept in distilled water.
View Article and Find Full Text PDFPolymers (Basel)
October 2022
Faculty of Technology, University of Niš, 16000 Leskovac, Serbia.
The manuscript aimed to review the types of acrylate polymers used in dentistry, as well as their chemical, physical, mechanical, and biological properties. Regarding their consistency and purpose, dental acrylate polymers are divided into hard (brittle), which includes acrylates for the production of plate denture bases, obturator prostheses, epitheses and maxillofacial prostheses, their repairs and lining, and soft (flexible), which are used for lining denture bases in special indications. Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized.
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