Printable and Machinable Dental Restorative Composites for CAD/CAM Application—Comparison of Mechanical Properties, Fractographic, Texture and Fractal Dimension Analysis

Thanks to the continuous development of light-curing resin composites it is now possible to print permanent single-tooth restorations. The purpose of this study was to compare resin composites for milling -Gandio Blocks(GR), Brilliant Crios(CR) and Enamic(EN) with resin composite for 3D printing—VarseoSmileCrown plus(VSC). Three-point bending was used to measure flexural strength (σf) and flexural modulus (Ef). The microhardness was measured using a Vickers method, while fractographic, microstructural, texture and fractal dimension (FD) analyses were performed using SEM, optical microscope and picture analysis methods. The values of σf ranged from 118.96 (±2.81) MPa for EN to 186.02 (±10.49) MPa for GR, and the values of Ef ranged from 4.37 (±0.8) GPa for VSC to 28.55 (±0.34) GPa for EN. HV01 ranged from 25.8 (±0.7) for VSC to 273.42 (±27.11) for EN. The filler content ranged from 19–24 vol. % for VSC to 70–80 vol. % for GR and EN. The observed fractures are typical for brittle materials. The correlation between FD of materials microstructure and Ef was observed. σf of the printed resin depends on layers orientation and is significantly lower than σf of GR and CR. Ef of the printed material is significantly lower than Ef of blocks for milling.

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Characterization of Experimental Short-Fiber-Reinforced Dual-Cure Core Build-Up Resin Composites

Polymers ◽

10.3390/polym13142281 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2281

Author(s):

Eija Säilynoja ◽

Sufyan Garoushi ◽

Pekka K. Vallittu ◽

Lippo Lassila

Keyword(s):

Fracture Toughness ◽

Resin Composite ◽

Rotating Disk ◽

Monomer Conversion ◽

Short Fiber ◽

Flexural Properties ◽

Resin Composites ◽

Fiber Reinforced ◽

Three Point Bending ◽

Light Curing

As a core build-up material, dual-cured (DC) resin-based composites are becoming popular. The aim of this research was to investigate specific physical and handling properties of new experimental short-fiber-reinforced DC resin composites (SFRCs) in comparison to different commercial, conventional DC materials (e.g., Gradia Core, Rebilda DC, LuxaCore Z, and Visalys® CemCore). Degree of monomer conversion (DC%) was determined by FTIR-spectrometry using either self- or light-curing mode. The flexural strength, modulus, and fracture toughness were calculated through a three-point bending setup. Viscosity was analyzed at room (22 °C) and mouth (35 °C) temperatures with a rotating disk rheometer. The surface microstructure of each resin composite was examined with scanning electron microscopy (SEM). Data were statistically analyzed with analysis of variance ANOVA (p = 0.05). The curing mode showed significant (p < 0.05) effect on the DC% and flexural properties of tested DC resin composites and differences were material dependent. SFRC exhibited the highest fracture toughness (2.3 MPa m1/2) values and LuxaCore showed the lowest values (1 MPa m1/2) among the tested materials (p < 0.05). After light curing, Gradia Core and SFRCs showed the highest flexural properties (p < 0.05), while the other resin composites had comparable values. The novel DC short-fiber-reinforced core build-up resin composite demonstrated super fracture toughness compared to the tested DC conventional resin composites.

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Rapid 3 s Curing: What Happens in Deep Layers of New Bulk-Fill Composites?

Materials ◽

10.3390/ma14030515 ◽

2021 ◽

Vol 14 (3) ◽

pp. 515

Author(s):

Danijela Marovic ◽

Matej Par ◽

Ana Crnadak ◽

Andjelina Sekelja ◽

Visnja Negovetic Mandic ◽

...

Keyword(s):

Mechanical Properties ◽

Raman Spectroscopy ◽

Flexural Strength ◽

Flexural Modulus ◽

Degree Of Conversion ◽

Resin Composites ◽

Three Point Bending ◽

Deep Layers ◽

Light Curing ◽

New Generation

This study assessed the influence of rapid 3 s light curing on the new generation of bulk-fill resin composites under the simulated aging challenge and depths up to 4 mm. Four bulk-fill materials were tested: two materials designed for rapid curing (Tetric PowerFill—PFILL; Tetric PowerFlow—PFLW) and two regular materials (Filtek One Bulk Fill Restorative—FIL; SDR Plus Bulk Fill Flowable—SDR). Three-point bending (n = 10) was used to measure flexural strength (FS) and flexural modulus (FM). In the 3 s group, two 2 mm thick specimens were stacked to obtain 4 mm thickness, while 2 mm-thick specimens were used for ISO group. Specimens were aged for 1, 30, or 30 + 3 days in ethanol. The degree of conversion (DC) up to 4 mm was measured by Raman spectroscopy. There was no difference between curing protocols in FS after 1 day for all materials except PFLW. FM was higher for all materials for ISO curing protocol. Mechanical properties deteriorated by increasing depth (2–4 mm) and aging. ISO curing induced higher DC for PFLW and FIL, while 3 s curing was sufficient for PFILL and SDR. The 3 s curing negatively affected FM of all tested materials, whereas its influence on FS and DC was highly material-specific.

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Fractal Dimension Analysis of Three-Point Bending Concrete Test Specimens

MATEC Web of Conferences ◽

10.1051/matecconf/202032301011 ◽

2020 ◽

Vol 323 ◽

pp. 01011

Author(s):

Jakub Sobek ◽

Petr Frantík ◽

Tomáš Trčka ◽

David Lehký

Keyword(s):

Fractal Dimension ◽

Programming Language ◽

Fractal Dimensions ◽

Optical Profilometry ◽

Three Point Bending ◽

Java Programming Language ◽

Fracture Surfaces ◽

Java Programming ◽

Dimension Analysis ◽

Fractal Dimension Analysis

The paper deals with the analysis of the fractal dimension of fracture surfaces of concrete specimens tested in a three-point bending configuration. Fifteen representative specimens were chosen out of a bigger set for the fractal dimension analysis. Their fracture surfaces were scanned by 2D optical profilometry and analysed by the FracDiM software created in the Java programming language. The resulting values of fractal dimensions for specimens of three different sizes are presented.

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Resin Composite Materials for Chairside CAD/CAM Restorations: A Comparison of Selected Mechanical Properties

Journal of Healthcare Engineering ◽

10.1155/2021/8828954 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Wojciech Grzebieluch ◽

Marcin Mikulewicz ◽

Urszula Kaczmarek

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Weibull Modulus ◽

Resin Composite ◽

Flexural Modulus ◽

Bending Test ◽

Weibull Analysis ◽

Three Point Bending ◽

Characteristic Strength ◽

Cad Cam

Objective. The aim was to evaluate the flexural strength, flexural modulus, microhardness, Weibull modulus, and characteristic strength of six resin composite blocks (Grandio Blocs-GR, Tetric CAD-TE, Brilliant Crios-CR, Katana Avencia-AV, Cerasmart-CS, and Shofu Block HC-HC). Methods. Flexural strength and flexural modulus were measured using a three-point bending test and microhardness using the Vickers method. Weibull analysis was also performed. Results. The materials showed flexural strength ranging from 120.38 (HC) to 186.02 MPa (GR), flexural modulus from 8.26 (HC) to 16.95 GPa (GR), and microhardness from 70.85 (AV) to 140.43 (GR). Weibull modulus and characteristic strength ranged from 16.35 (CS) to 34.98 (TE) and from 123.45 MPa (HC) to 190.3 MPa (GR), respectively. Conclusions. GR, TE, and CR presented significantly higher flexural strength, modulus, Weibull modulus, and characteristic strength than the others.

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