Hardness Evaluation of Dental Composite with Ceramic Fillers

2016 ◽  
Vol 696 ◽  
pp. 74-79 ◽  
Author(s):  
Nina Djustiana ◽  
Zulia Hasratiningsih ◽  
Elin Karlina ◽  
Renny Febrida ◽  
Veni Takarini ◽  
...  
Keyword(s):  
Sol Gel ◽  
Hardness Test ◽  
Dental Composite ◽  
Crystal Phase ◽  
Dental Composites ◽  
Tetraethylene Glycol ◽  
Transformation Toughening ◽  
Composites Materials ◽  
Urethane Dimethacrylate ◽  
Ceramic Fillers

In this study, new dental composites materials were developed. The two composites systems composed of zirconia (ZrO2), alumina (Al2O3) and silica (SiO2) (composites A) and zirconia (ZrO2), calcium (CaO), and silica (SiO2) (composites B) were synthesized through sol-gel method. These two systems were combined with urethane dimethacrylate and tetraethylene glycol dimethacrylate with 1% chitosan as coupling agent to build up the dental composites material. The resulting composites were subject to evaluation by microvickers hardness test and X-ray diffraction. The microvickers hardness test revealed that the hardness value for composites A and B were 24.48 and 21.9 VHN, respectively. Furthermore, the data were submitted to t-test (α=0,01) and it showed t count of both samples was 0,871 which means between the -t1-½α< t <t1-½α thus showing statistically the same average hardness value of both samples. Eventually, the new dental composites could be anticipated to apply in dental composites filler. The hardness results support the XRD result revealed that tetragonal crystal phase will help the transformation toughening mechanism and cubical crystal phase of zirconium dioxide. Both of the crystal phases were formed to stabilize the zirconia.

Commercial Dental Composite: Determination of Reaction Advancement and Study of the Migration of Organic Compounds

2005 ◽  
Vol 13 (3) ◽  
pp. 223-234
Author(s):  
C. Sanglar ◽  
M. Defay ◽  
H. Waton ◽  
A. Bonhomme ◽  
S. Alamercery ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Aqueous Media ◽  
Dental Composite ◽  
Dental Composites ◽  
Hydrophilic Monomer ◽  
Methacrylate Monomers ◽  
Urethane Dimethacrylate ◽  
Hydrolysis Of

This work on organic dental composites was undertaken to determine the role of residual reactive methacrylate functions at the end of the photopolymerization cycle, and to investigate the fate of the residual monomers and oligomers in organic (ethanol) and aqueous (water and artificial saliva) media. The results show that all the methacrylate monomers present in dentine migrate into ethanol (about 1% (w/w)). In aqueous media on the other hand, only the most hydrophilic monomer (UDMA) migrates (0.05% (w/w)) into water and 0.03% into artificial saliva (pH = 9). This desorption in the three media is accompanied by the hydrolysis of monomers, leading to the formation of monohydrolyzed urethane dimethacrylate (UDMA) and bis-phenyl glycidyl dimethacrylate (BISGMA); UDMA and BISGMA are completely hydrolyzed in artificial saliva. The alkalinity of the milieu apparently favours the hydrolysis of methacrylate functions.

Basic Properties of PMMA Reinforced Using Ceramics Particles of ZrO2-Al2O3-SiO2 Coated with Two Types of Coupling Agents

2016 ◽  
Vol 696 ◽  
pp. 93-98 ◽  
Author(s):  
Zulia Hasratiningsih ◽  
Arief Cahyanto ◽  
Veni Takarini ◽  
Elin Karlina ◽  
Nina Djustiana ◽  
...  
Keyword(s):  
Sol Gel ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Composites Materials ◽  
Silica Filler ◽  
Crystallographic Characteristic ◽  
Gel Technique ◽  
Silica Phases

In this study, novel composites materials composed of polymethyl methacrylate (PMMA) reinforced ZrO2-Al2O3-SiO2 filler system were developed. Zirconia-alumina-silica filler system were synthesized through sol-gel technique. Chitosan and trimethoxypropilsilane (TMPS) were used to modify the composites system. The resulting composites material were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and hardness test. SEM images displayed the composites particles in nanometer size with minor agglomeration. The XRD results revealed the presence of cubic and tetragonal phase of zirconia and also monoclinic silica phases in the composites system. These crystallographic characteristic could affect the mechanical properties of the composites. The hardness value for un-modified composites was 15.27 ± 0.25 VHN and for TMPS 19.43 ± 1.89 VHN and chitosan modification 18.75 ± 2.05 VHN, respectively. Therefore, these novel composites materials composed of PMMA reinforced filler system of zirconia-alumina-silica would provide the potential to apply in dental technology.

A triethylene glycol dimethacrylate- free dental composite for reduced water-sorption and shrinkage

2017 ◽  
Vol 52 (12) ◽  
pp. 1579-1588 ◽  
Author(s):  
Yuling Xu ◽  
Dong Xie
Keyword(s):  
Water Sorption ◽  
Triethylene Glycol ◽  
Dental Composite ◽  
Dental Composites ◽  
Screen Tool ◽  
Glycol Dimethacrylate ◽  
Triethylene Glycol Dimethacrylate ◽  
Commercial Resin ◽  
Urethane Dimethacrylate ◽  
Reduced Water

A number of new liquid urethane-based oligomers were synthesized, characterized and used to formulate the dental composites. Compressive strength and viscosity were used as a screen tool to evaluate the formed composites. Commercial available bisphenol A glycidyl methacrylate and urethane dimethacrylate-based systems were used as controls. Degree of conversion, shrinkage, water-sorption, solubility, flexural strength and diametrial tensile strength were evaluated. The results show that using mixed acrylate/methacrylate or methacrylates with different length to derivatize diisocyanates could be a good strategy to synthesize urethane-based oligomers in a liquid state. The developed triethylene glycol dimethacrylate-free urethane-based composites showed significantly reduced water sorption and solubility, decreased shrinkage and enhanced mechanical strength as compared to commercial resin-based ones.

Light-cured dental composites characterization by Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 428-429
Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Service Performance ◽  
Dental Composite ◽  
Dental Composites ◽  
Neat Resin ◽  
Scanning Calorimetry ◽  
Research Meeting ◽  
Formulation Variables

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.

scholarly journals The Photoinitiators Used in Resin Based Dental Composite—A Review and Future Perspectives

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 470
Author(s):  
Andrea Kowalska ◽  
Jerzy Sokolowski ◽  
Kinga Bociong
Keyword(s):  
Current Knowledge ◽  
Biomechanical Properties ◽  
Degree Of Conversion ◽  
Dental Composite ◽  
Polymerization Process ◽  
Dental Composites ◽  
Dental Resin ◽  
Dental Resins ◽  
Light Curing

The presented paper concerns current knowledge of commercial and alternative photoinitiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, benzophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this article was to point out alternative photoinitiators which would compensate the disadvantages of camphorquinone such as: yellow staining or poor biocompatibility and also would have mechanical properties as satisfactory as camphorquinone. Research showed there is not an adequate photoinitiator which can be as sufficient as camphorquinone (CQ), but alternative photosensitizers like: benzoyl germanium or novel acylphosphine oxide photoinitiators used synergistically with CQ are able to improve aesthetic properties and degree of conversion of dental resin.

scholarly journals Hardness evaluation of dental composites fabricated from the uniform size and well-distributed zirconia-alumina-silica fillers with sol-gel technique

2018 ◽  
Vol 30 (2) ◽  
pp. 78
Author(s):  
Muhammad Lukman Nur Hakim ◽  
Yanwar Faza ◽  
Zulia Hasratiningsih ◽  
Nina Djustiana ◽  
Bambang Sunendar
Keyword(s):  
Sol Gel ◽  
Tetragonal Zirconia ◽  
Dental Composite ◽  
Uniform Size ◽  
Calcination Process ◽  
Xrd Pattern ◽  
Sio2 System ◽  
Hardness Tester ◽  
Gel Technique ◽  
One Way Anova

Introduction: Several factor limits of services of dental composite have triggered further improvement. ZrO2-Al2O3-SiO2 system as filler of dental composite had been developed with sol-gel technique. Ultrasonic homogeniser were reported to change the particle size ditribution or shape. Unifom size and distribution of particle is believed to help define the behavior of hardness properties. Methods: The study was an laboratory experimental design. Filler ZrO2-Al2O3-SiO2 system were developed via sol-gel methods. Post calcination process, filler were immerse in ethanol and applied with ultrasonic homogeniser, with various amplitude i.e 50 rpm, 60 rpm and 80 rpm then named sample A, B, and C. XRD, SEM anda PSA were used to characterize of filler system. Subsequent filler were used to fabricate dental composite then evaluate the hardness value using micro-hardness tester. One–way ANOVA was used to analysis the statistical result of hardness value. Results: XRD pattern of three sample were similar in which tetragonal zirconia was prominent (57-61 %) followed by monoclinic zirconia (24-25%) and amorphous (15-17 %). While, SEM and PSA characterization showed amplitude 50 rpm (sample A) produce more uniform size and well-distributed particle filler than the others. In contrary, sample B and C showed higher peak in PSA results. It means there was dominating of filler with particular size.  However, the hardness value did not show significant differences between those filler (p>0,05). Conclusion: Dental composite that contain of different uniformity and distribution of filler ZrO2-Al2O3-SiO2 system has no significantly differences of hardness value.

scholarly journals Effect of different initial light intensity by the soft-start photoactivation on the bond strength and Knoop hardness of a dental composite

2007 ◽  
Vol 18 (2) ◽  
pp. 107-112 ◽  
Author(s):  
Eduardo Dall'Magro ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Américo Bortolazzo Correr ◽  
Lourenço Correr-Sobrinho ◽  
Simonides Consani ◽  
...  
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Hardness Test ◽  
Surface Region ◽  
Knoop Hardness ◽  
Dental Composite ◽  
The Other ◽  
Soft Start ◽  
Universal Testing ◽  
Push Out

This study evaluated the bond strength (push-out method) and Knoop hardness of Z250 composite resin, photoactivated with XL 2500 curing unit, using different protocols: continuous mode (700mW/cm² for 20s) (CO); soft-start (50 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS1); soft-start (100 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS2); soft-start (150 mW/cm² for 5 s, followed by 700mW/cm² for 15s) (SS3); soft-start (200mW/cm² for 5s, followed by 700mW/cm² for 15s) (SS4); soft-start (250mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS5); soft-start (300 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS6). For the push-out test, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. For the hardness test, the specimens were polished for the hardness measurements, using a 50 g load for 15 s. Data were submitted to ANOVA and Tukey's test (alpha=5%). The results of bond strength showed that the SS3 group obtained the highest bond strength when compared to the CO group. There were no significant differences among the other modes in relation to the other groups. Regarding the other results in hardness, there were no significant differences among the groups in the surface region and up to 4 mm depth.

Mechanical Properties of Machinable Zirconia Dental Composites

2007 ◽  
Vol 336-338 ◽  
pp. 1587-1589
Author(s):  
Wen Xu Li ◽  
Hua Zhao ◽  
Ying Song ◽  
Bin Su ◽  
Fu Ping Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Calcium Phosphate ◽  
Flexural Strength ◽  
Dental Composite ◽  
The Other ◽  
Dental Composites ◽  
Composite Ceramics ◽  
Cad Cam ◽  
The Common

Ca3(PO4)2/ZrO2 dental composite ceramics using for CAD/CAM system were prepared and the effects of weak phases on microstructures and mechanical properties were studied. The results showed that intergranular spreads happened with the increasing Ca3(PO4)2 contents due to the discontinuity of weak interfaces between Zirconia and Calcium phosphate in matrix. So the flexural strength and hardness of the Ca3(PO4)2/ZrO2 composite ceramics were decreased effectively, which improved the machinability of the composites. On the other hand, strong interfaces between Zirconias increased the integrality of the ceramic structures. ZrO2 composite Ceramics with 15% Ca3(PO4)2 were sintered at 1350°C. The flexural strength is 300.44MPa, fracture toughness is 4.36 MPam1/2, and hardness is 6.69 GPa. The cutting exponent of the Ca3(PO4)2/ZrO2 composite ceramics is obviously lower than that of the common commercial Vita Mark II and Dicor MGC ceramics, which shows good mechanical properties and machinability.

Factors towards Pencil Scratch Resistance of Protective Sol-Gel Coatings on Polycarbonate Substrate

2006 ◽  
Vol 312 ◽  
pp. 339-344 ◽  
Author(s):  
Edmund Chwa ◽  
Linda Wu ◽  
Z. Chen
Keyword(s):  
Fracture Toughness ◽  
Colloidal Silica ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Hardness Test ◽  
Scratch Resistance ◽  
Indentation Hardness ◽  
Pencil Hardness ◽  
Film Cracking ◽  
Polycarbonate Substrate

Sol-gel coatings with different amount of colloidal silica were prepared on polycarbonate substrate. The scratch resistance was measured by the pencil hardness test based on ASTM Standard D3363-00. The indentation hardness, elasticity modulus and fracture toughness of the coatings were also characterized and correlated to the observed pencil hardness. The scratch failure was found to be due to film cracking at the trailing end. Based on such an observation, the current analysis points out that the main factors towards scratch resistance are elasticity modulus, thickness and fracture toughness of the film.

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