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

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.

Download Full-text

Evaluation of New Hollow Sleeve Composites for Direct Post-Core Construction

Materials ◽

10.3390/ma14237397 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7397

Author(s):

Shinji Yoshii ◽

Sufyan Garoushi ◽

Chiaki Kitamura ◽

Pekka K. Vallittu ◽

Lippo V. Lassila

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Resin Composite ◽

Flexural Modulus ◽

Accelerated Aging ◽

Fracture Analysis ◽

Bending Test ◽

Outer Diameter ◽

Fiber Post ◽

Three Point Bending

The preset shape and diameter of a prefabricated FRC post rarely follows the anatomy of the root canal. To solve this problem, a new hollow sleeve composite (HSC) system for post-core construction was developed and characterized. A woven fiber was impregnated with two types of resins: Bis-GMA or PMMA, and rolled into cylinders with outer diameter of 2 mm and two different inner diameters, namely 1.2 or 1.5 mm. The commercial i-TFC system was used as a control. Dual-cure resin composite was injected into these sleeves. Additionally, conventional solid fiber post was used as the inner part of the sleeve. The three-point bending test was used to measure the mechanical properties of the specimens and the fracture surface was examined using an electron microscope (SEM). The HSC (1.5 mm, Bis-GMA) revealed a statistically similar flexural modulus but higher flexural strength (437 MPa) compared to i-TFC (239 MPa; ANOVA, p < 0.05). When a fiber post was added inside, all values had a tendency to increase. After hydrothermal accelerated aging, the majority of specimens showed a significant (p < 0.05) decrease in flexural strength and modulus. SEM fracture analysis confirmed that the delamination occurred at the interface between the outer and inner materials. The HSC system provided flexibility but still high mechanical values compared to the commercial system. Thus, this system might offer an alternative practical option for direct post-core construction.

Download Full-text

THE INFLUENCE OF SiC COATING PROCESS ON THE PROPERTIES OF C/C COMPOSITES

Surface Review and Letters ◽

10.1142/s0218625x07010317 ◽

2007 ◽

Vol 14 (04) ◽

pp. 817-820

Author(s):

MIN HUANG ◽

KE-ZHI LI ◽

HE-JUN LI ◽

QIAN-GANG FU ◽

GUO-DONG SUN

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Failure Mode ◽

Flexural Modulus ◽

Pack Cementation ◽

Bending Test ◽

Carbon Composites ◽

Coating Process ◽

Three Point Bending ◽

Coated Carbon

SiC coating for carbon/carbon composites was prepared by pack cementation method. The effects of coating process on the microstructure and the mechanical properties of C / C composites were analyzed by SEM and three-point bending test, respectively. As the infiltrated Si improved the interfaces bonding during the coating process, the flexural strength and flexural modulus of SiC -coated carbon/carbon composites were both increased by about 10% than the naked C / C composites. In addition, the mechanism of the change of failure mode of SiC coated C / C composites and naked C / C composites was addressed.

Download Full-text

Influence of a Repeated Preheating Procedure on Mechanical Properties of Three Resin Composites

Operative Dentistry ◽

10.2341/13-238-l ◽

2015 ◽

Vol 40 (2) ◽

pp. 181-189 ◽

Cited By ~ 6

Author(s):

M D'Amario ◽

F De Angelis ◽

M Vadini ◽

N Marchili ◽

S Mummolo ◽

...

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Vickers Microhardness ◽

Flexural Modulus ◽

Bending Test ◽

Resin Composites ◽

Three Point Bending ◽

Main Effect ◽

Dependent Variables ◽

Marginal Means

SUMMARY The aim of this study was to assess the flexural strength, flexural elastic modulus and Vickers microhardness of three resin composites prepared at room temperature or cured after one or repeated preheating cycles to a temperature of 39°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium), Opallis (FGM), and Ceram X Duo (Dentsply DeTrey). For each trial, one group of specimens of each material was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 1, 10, 20, 30, or 40 preheating cycles to a temperature of 39°C in a preheating device. Ten rectangular prismatic specimens (25 × 2 × 2 mm) were prepared for each group (N=180; n=10) and subjected to a three-point bending test for flexural strength and flexural modulus evaluation. Vickers microhardness was assessed on 10 cylindrical specimens from each group (N=180; n=10). Statistical analysis showed that, regardless of the material, the number of heating cycles was not a significant factor and was unable to influence the three mechanical properties tested. However, a significant main effect of the employed material on the marginal means of the three dependent variables was detected.

Download Full-text

Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽

10.3390/polym13111745 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1745

Author(s):

Tamaki Hada ◽

Manabu Kanazawa ◽

Maiko Iwaki ◽

Awutsadaporn Katheng ◽

Shunsuke Minakuchi

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Water Sorption ◽

Water Solubility ◽

Flexural Modulus ◽

Manufacturing Method ◽

Heat Curing ◽

Significant Difference ◽

Cad Cam ◽

Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

Download Full-text

Effect of Filler Content and Waiting time Before Light-Curing on Mechanical Properties of Dual-Cured Cement

Current Dentistry ◽

10.2174/2542579x01666190924180448 ◽

2020 ◽

Vol 2 (1) ◽

pp. 45-52

Author(s):

Ana C. de Assunção Oliveira ◽

Sandro Griza ◽

Rafael R. de Moraes ◽

André L. Faria-e-Silva

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Flexural Strength ◽

Waiting Time ◽

Filler Content ◽

Bending Test ◽

Resin Cements ◽

Three Point Bending ◽

Light Curing ◽

Curing Procedure

Objective:: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement. Methods:: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to oneway ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05). Results:: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler. Conclusion:: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

Download Full-text

Effect of Thermocycling on Biaxial Flexural Strength of CAD/CAM, Bulk Fill, and Conventional Resin Composite Materials

Operative Dentistry ◽

10.2341/18-146-l ◽

2019 ◽

Vol 44 (5) ◽

pp. E254-E262 ◽

Cited By ~ 4

Author(s):

EB Benalcázar Jalkh ◽

CM Machado ◽

M Gianinni ◽

I Beltramini ◽

MMT Piza ◽

...

Keyword(s):

Composite Materials ◽

Flexural Strength ◽

Weibull Modulus ◽

Resin Composite ◽

Oral Care ◽

Testing Machine ◽

Biaxial Flexural Strength ◽

Computer Aided ◽

Cad Cam ◽

Characteristic Stress

SUMMARY New resin-based restorative materials have been developed, such as computer-aided design/computer-aided manufacturing (CAD/CAM) and bulk-fill composites, as an alternative to traditional layering techniques. This study evaluated the biaxial flexural strength (BFS) before and after thermocycling of five different resin composites: one hybrid resin/ceramic CAD/CAM indirect material, Lava Ultimate CAD-CAM Restorative (LU, 3M Oral Care); a conventional composite, Filtek Z350 XT (Z350, 3M Oral Care); two bulk-fill composites, Tetric N-Ceram Bulk Fill (TBF, Ivoclar Vivadent) and Filtek Bulk Fill (FBF, 3M Oral Care); and one bulk-fill flow resin composite, Filtek Bulk Fill Flow (FBFF, 3M Oral Care). Three hundred disc-shaped specimens (6.5 mm in diameter and 0.5 mm thick) were fabricated and divided into five groups (n=30 for each composite and condition). The BFS test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min immediately (i, 24 hours) and after thermocycling (a, 500 thermal cycles of 5°C to 55°C with a 30-second dwell time). The Weibull modulus (m) and characteristic stress (η) were calculated, and a contour plot was used (m vs η) to detect differences between groups (95% two-sided confidence intervals). Significantly higher characteristic stress was observed for LUi (286.6 MPa) and Z350i (248.8 MPa) compared to the bulk-fill groups (FBFi=187.9 MPa, FBFFi=175.9 MPa, TBFi=149.9 MPa), with no differences between LUi and Z350i. Thermocycling significantly decreased the characteristic stress of all groups with the highest values observed for LUa (186.7 MPa) and Z350a (188.9 MPa) and the lowest for FBFFa (90.3 MPa). Intermediate values were observed for FBFa (151.6 MPa) and TBFa (122.8 MPa). The Weibull modulus decreased only for FBFa compared to FBFi. Composition and thermocycling significantly influenced the biaxial flexural strength of resin composite materials.

Download Full-text

The Thermal Shock Resistance of Mg-PSZ/LaPO4 Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.785-786.187 ◽

2013 ◽

Vol 785-786 ◽

pp. 187-190

Author(s):

Zhong Qiu Li ◽

Li Jie Ci ◽

Tie Cheng Feng ◽

Shao Yan Zhang

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Thermal Shock ◽

Thermal Shock Resistance ◽

Strength Degradation ◽

Water Quenching ◽

Bending Test ◽

Three Point Bending ◽

Shock Resistance ◽

Thermal Shock Behavior

The mechanical properties and thermal shock behavior of Mg-PSZ/LaPO4 ceramics was investigated. The thermal shock resistance of the materials was evaluated by water quenching and a subsequent three-point bending test to determine the flexural strength degradation. Mg-PSZ/15LaPO4 composite showed a higher thermal shock resistance and behaved as a typical refractory. The calculation of thermal shock resistance parameters for the composites and the monolith had indicated possible explanations for the differences in thermal shock behavior.

Download Full-text

The Effects of MgO Addtion on the Mechanical Properties and the Phase Composition of Al2O3-TiC-TiN Ceramic Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.457-458.3 ◽

2012 ◽

Vol 457-458 ◽

pp. 3-6

Author(s):

Yu Huan Fei ◽

Chuan Zhen Huang ◽

Han Lian Liu ◽

Bin Zou

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Phase Composition ◽

Flexural Strength ◽

Ceramic Materials ◽

Bending Test ◽

Vickers Indentation ◽

Volume Percent ◽

Sintered Ceramic ◽

Three Point Bending

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. Three point bending test was applied to get the flexural strength and the Vickers indentation was applied to get the Vickers hardness and the fracture toughness. The phase composition of the ceramics was analyzed by XRD. The effects of the content of MgO on the mechanical properties and the phase composition of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. The convertion of the mechanical properties can also be explained by the XRD results.

Download Full-text

Effects of Different Storage Conditions on Mechanical Properties of CAD/CAM Restorative Materials

Odovtos - International Journal of Dental Sciences ◽

10.15517/ijds.2020.38742 ◽

2019 ◽

pp. 161-174

Author(s):

Ayşe Atay DDS, PhD ◽

Elçin Sağirkaya DDS, PhD

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Vickers Hardness ◽

Flexural Modulus ◽

Water Storage ◽

Storage Conditions ◽

Flexural Test ◽

Cad Cam ◽

Provisional Restoration ◽

Hardness Values

The aim of this study was to evaluate mechanical properties of six new-generation all-ceramic materials for CAD/CAM (Lava Ultimate [LU], VITA Mark II [VM], InCoris TZI [IC], IPS e.max CAD [EM], VITA Suprinity [VS], IPS Empress CAD [EC]) and two different provisional restoration CAD/CAM materials (Telio CAD [TC], Vita CAD-Temp [VC]) after different storage conditions. 36 bar-shaped samples of 4 mm in width and 14 mm in length with 1.2 mm thicknesses were prepared from each material group (N=288). The specimens from each material were kept under three different storage conditions (n=12): under dry conditions at room temperature; 37°C distilled water for 7 days; and 37°C distilled water for 7 days followed by 10,000 thermal cycles. All specimens were subjected to a 3-point flexural test with a crosshead speed of 1.0 mm/min. The specimens were loaded until failure. Twelve fractured specimens after the flexural test from each group were used for the Vickers hardness test (under 300 gf of loading in 15 seconds). The flexural modulus, flexural strength and Vickers hardness values were separately analyzed with two-way analysis of variance, Tukey’s multiple comparison tests at a significance level of p<0.05. There were statistically significant differences between materials and storage conditions according to flexural modulus, flexural strength and Vickers hardness values (p<0.05). The flexural strength, flexural modulus and Vickers hardness values of LU, VC, TC, VS and IC decreased after water storage followed by thermal cycling (p<0.05). The mechanical properties of provisional restoration CAD/CAM materials had showed a significantly decrease after water storage followed by thermal cycles but their mechanical properties were acceptable for fabrication of provisional restorations. The mechanical properties of VM, EC and EM were not affected by different storage conditions whereas IC and VS were affected.

Download Full-text

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

Materials ◽

10.3390/ma14174919 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4919

Author(s):

Wojciech Grzebieluch ◽

Piotr Kowalewski ◽

Dominika Grygier ◽

Małgorzata Rutkowska-Gorczyca ◽

Marcin Kozakiewicz ◽

...

Keyword(s):

Fractal Dimension ◽

Resin Composite ◽

Flexural Modulus ◽

Optical Microscope ◽

Resin Composites ◽

Three Point Bending ◽

Dimension Analysis ◽

Cad Cam ◽

Light Curing ◽

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.

Download Full-text