Objectives: This study aimed to evaluate the surface gloss, surface roughness, and color change of restorative materials after a three-body wear abrasion.
Methods And Materials: Four resin composites with different filler particle size (Gracefil Flo [GFF, 0.7 μm], Gracefil LoFlo [GFL, 0.25 μm], Gracefil ZeroFlo [GFZ, 0.15 μm], and Gracefil Putty [GFP, 0.3 μm]), two CAD/CAM resin composite blocks with different filler particle size (Cerasmart 300 [CS3, 0.7 μm] and Cerasmart Prime [CSP, 0.3 μm], GC), and one CAD/CAM lithium disilicate glass-ceramic block (Initial LiSi Block [ILS], GC) as a control were evaluated. Twenty slab-shaped specimens were obtained from each material. Ten specimens were subjected to 80,000 toothbrushing strokes and measured for surface gloss (Gloss Unit, GU), surface roughness (Ra, μm), and color (L*, a*, and b* values) before toothbrushing and at every 20,000 strokes. Color differences (ΔL*, Δa*, Δb*, and ΔE00) before and after toothbrushing were calculated. After 80,000 strokes, abraded surfaces were observed using scanning electron microscopy. The other 10 specimens were measured for Vickers microhardness (VHN).
Results: After 80,000 toothbrushing strokes, the mean GU ranged from 60.43 to 16.12 (the highest for ILS and lowest for GFL), and the mean Ra ranged from 0.079 to 4.085 (the lowest for ILS and highest for GFL). At all measuring stages, the calculated ΔE00 values ranged from 0.31 to 0.92 for all materials. The mean VHN ranged from 632.34 to 39.08 (the highest for ILS and lowest for GFZ). The resin composite containing the largest filler particle (GFF) showed significantly lower Ra and higher VHN than other resin composites (GFL, GFZ, and GFP). The CAD/CAM resin composite block containing a smaller filler particle (CSP) retained significantly higher GU than that containing a larger filler particle (CS3). A negative correlation between GU and Ra was detected.
Conclusions: Based on the findings, toothbrush abrasion induced a decrease in GU and an increase in Ra for all resin-based materials tested. Resin-based materials with larger filler size tended to show lower Ra, while resin-based materials with smaller filler size tended to show a smaller reduction in GU. These were more pronounced for light-cure resin composites than for resin composite blocks for CAD/CAM.
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http://dx.doi.org/10.2341/22-123-L | DOI Listing |
Sci Rep
January 2025
College of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Uneven of filling aggregate gradation may cause transportation problems such as pipe blockage due to segregation and stratification of filling slurry. To study the influence of aggregate gradation on the conveying performance of filler slurry, aggregate gradation experiments were carried out, rheological tests on slurries with coal gangue/aeolian sand ratios (6:4, 5:5 and 4:6) showed that appropriately increasing the proportion of aeolian sand can improve particle gradation. Computational fluid dynamics (CFD) scheme was used to simulate the pipeline transportation characteristics of the slurry under the conditions of three sets each of coal gangue/aeolian sand ratios, slurry concentrations (72%,74% and 76%), and inlet velocities (1.
View Article and Find Full Text PDFSci Rep
January 2025
School of Railway Engineering, Hunan Technical College of Railway High-Speed, Hengyang, 421002, China.
Research on the evolutionary behavior of the particle breakage processes in coarse-grained soil under the action of train load is of practical significance for subgrade construction and maintenance. However, existing studies have not addressed the prediction of particle size distribution evolution. In this paper, the MTS loading system is used to simulate the dynamic train load effect on coarse-grained soil fillers.
View Article and Find Full Text PDF3D Print Addit Manuf
October 2024
Department of Mechanical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
Digital light processing (DLP) is rapidly growing in popularity as an additive manufacturing method for the fabrication of composite structures, and is an effective way to prepare high-resolution filled parts, such as ceramic green parts or composite magnets. Yet, higher solid loadings of resins and the resulting dramatic increases in viscosity limit DLP printing for applications that depend upon maximization of filler content. In this work, we investigate the capacity of a bimodal particle size distribution to enable the printing of a photosensitive resin containing up to 70 vol% of fillers.
View Article and Find Full Text PDFDeveloping novel materials is an essential requirement in the engineering field. This study investigates the effects of incorporating wood dust particles on the mechanical and erosive wear properties of Luffa acutangula fiber (LAF)-reinforced phenol-formaldehyde composites, fabricated using the hand layup method with a constant 20% fiber content and varying wood dust particle contents of 0%, 10%, 20%, and 30%. Using the Taguchi method, the study identifies the optimal combination for minimizing erosive wear - 20% wood dust content, 45 m/s impact velocity, 60° impingement angle, 600 μm erodent size, and 60 mm standoff distance-achieving a minimum erosion rate of 189.
View Article and Find Full Text PDFBiomimetics (Basel)
December 2024
Department of Operative Dentistry, Aichi Gakuin School of Dentistry, Nagoya 464-8651, Japan.
Universal shade flowable composites have been introduced to mimic tooth structure with reduced color mismatch and reduced chair time and cost. However, the polymerization shrinkage of resin material may lead to sensitivity and restoration failure. The purpose of this study was to compare the polymerization shrinkage of recently introduced universal shade flowable resin-based composites using both wet and dry density methods.
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