Effect of Speed of Loading on Compressive Strength and Flexural Strength of Dental Resin-Composites

The aim of current in vitro research was to determine the effect of hydrothermal accelerated aging on the mechanical properties and wear of different commercial dental resin composites (RCs). In addition, the effect of expiration date of the composite prior its use was also evaluated. Five commercially available RCs were studied: Conventional RCs (Filtek Supreme XTE, G-aenial Posterior, Denfil, and >3y expired Supreme XTE), bulk-fill RC (Filtek Bulk Fill), and short fiber-reinforced RC (everX Posterior). Three-point flexural test was used for determination of ultimate flexural strength (n = 8). A vickers indenter was used for testing surface microhardness. A wear test was conducted with 15,000 chewing cycles using a dual-axis chewing simulator. Wear pattern was analyzed by a three-dimensional (3D) noncontact optical profilometer. Degree of C=C bond conversion of monomers was determined by FTIR-spectrometry. The specimens were either dry stored for 48 h (37 °C) or boiled (100 °C) for 16 h before testing. Scanning electron microscopy (SEM) was used to evaluate the microstructure of each material. Data were analyzed using ANOVA (p = 0.05). Hydrothermal aging had no significant effects on the surface wear and microhardness of tested RCs (p > 0.05). While flexural strength significantly decreased after aging (p < 0.05), except for G-aenial Posterior, which showed no differences. The lowest average wear depth was found for Filtek Bulk Fill (29 µm) (p < 0.05), while everX Posterior and Denfil showed the highest wear depth values (40, 39 µm) in both conditions. Passing the expiration date for 40 months did not affect the flexural strength and wear of tested RC. SEM demonstrated a significant number of small pits on Denfil’s surface after aging. It was concluded that the effect of accelerated aging may have caused certain weakening of the RC of some brands, whereas no effect was found with one brand of RC. Thus, the accelerated aging appeared to be more dependent on material and tested material property.

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Effect of Low Shrinkage Monomers on Physicochemical Properties of Dental Resin Composites

Brazilian Dental Journal ◽

10.1590/0103-6440201300401 ◽

2015 ◽

Vol 26 (3) ◽

pp. 272-276 ◽

Cited By ~ 5

Author(s):

Dayane Carvalho Ramos Salles de Oliveira ◽

Karla Rovaris ◽

Viviane Hass ◽

Eduardo José Souza-Júnior ◽

Francisco Haiter-Neto ◽

...

Keyword(s):

Flexural Strength ◽

Physicochemical Properties ◽

Statistical Difference ◽

Resin Composite ◽

Multiple Comparisons ◽

Resin Composites ◽

Dental Resin ◽

Tukey Test ◽

Dental Resin Composites ◽

One Way Anova

The aim of this study was to evaluate the effect of low shrinkage monomers on physicochemical properties of dental resin composites. Two low shrinkage resin composites: one with a crosslink branching monomer (Kalore, GC Corp) and a novel monomer (Venus Diamond, Heraeus Kulzer) were compared to a conventional resin composite formulation (Filtek Z250, 3M/ESPE). The volumetric shrinkage was evaluated by µCT analysis (n=5) and the physicochemical properties by degree of C=C conversion (DC), flexural strength (FS) and Young's modulus (YM) (n=10). All samples were light cured by a LED device (Radii, SDI) with 16 J/cm2. The results were analysed by one-way ANOVA and Tukey test for multiple comparisons (α=0.05). No statistical difference was found between µCT shrinkage values to Kalore (1.8%) and Venus Diamond (1.7%) (p≥0.05); Z250 presented statistical highest shrinkage value (2.0%). Kalore presented higher statistical DC (60.8%) than Venus Diamond (49.5%) and Z250 (49.6%). No statistical difference was found between FS or YM properties to Venus Diamond and Z250; Kalore presented statistical lowest FS and YM properties (p≥0.05). Conclusion: Using novel monomers seem to reduce polymerization shrinkage without affecting the physicochemical properties evaluated of resin composites rather than using crosslink branching monomers.

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Effect of Modification of Aluminum Borate Whiskers with Three Methods on Flexural Properties of Dental Resin Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.364.687 ◽

2013 ◽

Vol 364 ◽

pp. 687-691

Author(s):

Yan Bo Yuan ◽

Xing Xing Li ◽

Wen Yun Zhang ◽

Qing Hua Chen ◽

Yu Hong Xiao ◽

...

Keyword(s):

Flexural Strength ◽

Sol Gel ◽

Flexural Properties ◽

Resin Composites ◽

Dental Resin ◽

Dental Resin Composites ◽

Aluminium Borate ◽

Significant Difference ◽

Group A ◽

Group B

This study aimed to compare three different methods for the modification of aluminium borate whiskers and investigate the effect of aluminium borate whiskers composites on flexural properties of dental resin composites. Method A was to mix aluminium borate whiskers and silicon dioxide (SiO2) nanoparticles directly. Method B was to modify the mixture of aluminium borate whiskers and SiO2nanoparticles with sol-gel process of tetraethoxysilane (TEOS). Method C was to modify the aluminium borate whiskers with SiO2nanoparticles which were repaired by sol-gel method of TEOS. The effects of the three methods were characterized by the TEM and SEM. There was a significant difference (p<0.05) in the flexural strength among three methods. Group C had a flexural strength of 149.59 ± 12.86 MPa (mean ± SD; n = 5), which is significantly higher than 95.28 ± 4.53 MPa for Group A and 123.14 ± 17.37 MPa for Group B. It is concluded that ceramic whisker reinforcement significantly improves the flexural properties of resin composites; different methods produce different effects.

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Effect of Filler Ratio on Properties of Nanohydroxyapatite/SiO2 Based Bioactive Dental Resin Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.745-746.466 ◽

2013 ◽

Vol 745-746 ◽

pp. 466-472 ◽

Cited By ~ 3

Author(s):

Feng Wei Liu ◽

Jing Hang Hu ◽

Rui Li Wang ◽

Ying Ying Pan ◽

Xiao Ze Jiang ◽

...

Keyword(s):

Compressive Strength ◽

Water Sorption ◽

Filler Loading ◽

Dental Composite ◽

Lower Amount ◽

Resin Composites ◽

Dental Resin ◽

Bioactive Materials ◽

Solubility In Water ◽

Dental Resin Composites

Hydroxyapatite (HAP), as an essential component of bone and tooth, is one of the promising bioactive materials. The purpose of this study was to investigate the effects of incorporation of nanoHAP and SiO2 particles on the properties of bioactive dental composite. Silanized HAP and SiO2 were mixed with BisGMA/TEGDMA (1/1 wt/wt) monomers at various HAP/SiO2 mass ratios of 0:7 (no HAP), 5.25/1.75, 3.5/3.5, 1.75/5.25, 7:0 (no SiO2) to yield a series of pastes all containing 70 wt% filler loading. The results showed that flexural strength, elastic modulus and compressive strength gradually decreased with increasing amount of HAP particles, as well as curing depth and polymerization shrinkage, which resulted from the nature of HAP particle material. Water sorption and solubility in water increased slightly with addition of HAP particles. Degree of conversion test could support results above well. Remineralization test in SBF demonstrated dental composite with HAP particles had a good apatite-forming ability. Consequently, dental composite filled with lower amount of nanoHAP (HAP/SiO2 around 0.25) particles would possess better comprehensive performances.

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