Background: Repeated fracture of the denture base is a common problem in prosthodontics, and it represents a nuisance and a time sink for the clinician. Therefore, the possibility of increasing repair strength using new reinforcement materials is of great interest to prosthodontists.
Aim Of The Study: This study aimed to evaluate the effects of incorporation of zirconia nanoparticles (nano-ZrO) on the flexural strength and impact strength of repaired polymethyl methacrylate (PMMA) denture bases.
Materials And Methods: One hundred eighty specimens of heat-polymerized acrylic resin were fabricated (90 for each test) and divided into three main groups: one control group (intact specimens) and two groups divided according to surface design (45° bevels and butt joints), in which specimens were prepared in pairs to create 2.5 mm gaps. Nano-ZrO was added to repair resin in 2.5 wt%, 5 wt%, and 7.5 wt% concentrations of acrylic powder. A three-point bending test was used to measure flexural strength, and a Charpy-type test was used to measure impact strength. Scanning electron microscopy was used to analyze the fracture surfaces and nano-ZrO distribution. The results were analyzed with a paired sample -test and an unpaired -test, with a -value of ≤0.05 being significant.
Results: Incorporation of nano-ZrO into the repair resin significantly increased flexural strength (<0.05). The highest value was found in the bevel group reinforced with 7.5% nano-ZrO, whereas the lowest value was found in the butt group reinforced with 2.5% nano-ZrO. The impact strength values of all repaired groups were significantly lower than those of the control group (<0.05). Among repaired groups, the higher impact strength value was seen in the butt group reinforced with 2.5% nano-ZrO. The bevel joint demonstrated mainly cohesive failure, whereas the butt joint demonstrated mainly adhesive failure.
Conclusion: Incorporation of nano-ZrO into the repair resin improved the flexural strength of repaired denture bases, whereas it decreased impact strength, especially with high nano-ZrO concentrations.
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http://dx.doi.org/10.2147/IJN.S120054 | DOI Listing |
Nano Lett
January 2025
National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China.
Wood particle boards are massively used in construction and household products. But they often raise health and environmental concerns because of the formaldehyde-based adhesives. More sustainable and high-strength particle boards are developed on a bio-based materials or their derivatives.
View Article and Find Full Text PDFJ Prosthet Dent
December 2024
Associate Professor, Dental Biomaterials Research Laboratory, Department of Restorative Dentistry, Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address:
Statement Of Problem: The mechanical properties and microstructure of cobalt chromium (Co-Cr) alloys should be considered when choosing the best alloy for each clinical situation. More information is needed on the digital manufacturing methods of metals in dentistry, such as computer numerical control (CNC), and direct laser metal sintering (DMLS).
Purpose: The aim of this study was to investigate the effect of the 3 different Co-Cr manufacturing processes on the mechanical properties and microstructure of Co-Cr dental alloys.
Sci Rep
December 2024
Civil Engineering Department, Shoolini University, Solan, Himachal Pradesh, 173229, India.
Geopolymer concrete (GPC) offers a sustainable alternative by eliminating the need for cement, thereby reducing carbon dioxide emissions. Using durable concrete helps prevent the corrosion of reinforcing bars and reduces spalling caused by chemical attacks. This study investigates the impact of adding 5, 10, and 15% silica fumes (SF) on the mechanical and durability properties of GPC cured at 60 °C for 24 h.
View Article and Find Full Text PDFBMC Oral Health
December 2024
Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC, Institute of Dentistry, University of Turku, Turku, Finland.
Background: Short fiber-reinforced composites (SFRCs) are restorative materials for large cavities claimed to effectively resist crack propagation. This study aimed to compare the mechanical properties and physical characteristics of five commercially available SFRCS (Alert, Fibrafill Flow, Fibrafill Dentin, everX Flow, and everX Posterior) against a conventional particulate-filled composite (PFC, Essentia Universal).
Methods: The following characteristics were evaluated in accordance with ISO standards: flexural strength and modulus and fracture toughness.
Sci Rep
December 2024
Student Research Committee, Department of Epidemiology, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Very high heat is generated during the polymerization of poly (methyl methacrylate) (PMMA) bone cement, which is used for implant fixation in orthopedic surgery. As such, it has been suggested that irrigating the bone cement layer in the surgical site with a saline solution is a way of cooling the layer. In this study, we aimed to determine the influence of irrigation with a saline solution on the flexural strength and the microstructure of the test specimens of two PMMA bone cement brands: Simplex P and FIX 1.
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