scholarly journals Bulk Fill Composites Have Similar Performance to Conventional Dental Composites

2020 ◽  
Vol 21 (14) ◽  
pp. 5136 ◽  
Author(s):  
Håvard J. Haugen ◽  
Danijela Marovic ◽  
Matej Par ◽  
Minh Khai Le Thieu ◽  
Janne E. Reseland ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Flexural Modulus ◽  
Filler Particle ◽  
Triethylene Glycol ◽  
Particle Morphology ◽  
Degree Of Conversion ◽  
Depth Of Cure ◽  
Urethane Dimethacrylate ◽  
Filler Mass ◽  
Fill Materials

The aim of the study was to perform comprehensive characterization of two commonly used bulk fill composite materials (SDR Flow (SDR) and Filtek™ Bulk Fill Flowable Restorative (FBF) and one conventional composite material (Tetric EvoCeram; TEC). Eleven parameters were examined: flexural strength (FS), flexural modulus (FM), degree of conversion, depth of cure, polymerisation shrinkage (PS), filler particle morphology, filler mass fraction, Vickers hardness, surface roughness following simulated toothbrush abrasion, monomer elution, and cytotoxic reaction of human gingival fibroblasts, osteoblasts, and cancer cells. The degree of conversion and depth of cure were the highest for SDR, followed by FBF and TEC, but there was no difference in PS between them. FS was higher for bulk fill materials, while their FM and hardness were lower than those of TEC. Surface roughness decreased in the order TEC→SDR→FBF. Bisphenol A-glycidyl methacrylate (BisGMA) and urethane dimethacrylate were found in TEC and FBF eluates, while SDR released BisGMA and triethylene glycol dimethacrylate. Conditioned media accumulated for 24 h from FBF and TEC were cytotoxic to primary human osteoblasts. Compared to the conventional composite, the tested bulk fill materials performed equally or better in most of the tests, except for their hardness, elastic modulus, and biocompatibility with osteoblasts.

scholarly journals Monomers used in resin composites: degree of conversion, mechanical properties and water sorption/solubility

2012 ◽  
Vol 23 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Vinícius E. S. Gajewski ◽  
Carmem S. Pfeifer ◽  
Nívea R. G. Fróes-Salgado ◽  
Letícia C. C. Boaro ◽  
Roberto R. Braga
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Flexural Modulus ◽  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Resin Composites ◽  
Triethylene Glycol Dimethacrylate ◽  
Three Point Bending ◽  
Rate Of Polymerization ◽  
Urethane Dimethacrylate

The organic phase of resin composites is constituted by dimethacrylate resins, the most common monomers being the bisphenol A diglycidildimethacrylate (BisGMA), its ethoxylated version (BisEMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). This study compared the homopolymers formed from the monomers used in restorative dental composites in terms of their degree of conversion (DC) and reaction kinetics (by near infra-red spectroscopy, n=3), mechanical properties (flexural modulus and strength in three point-bending, FM and FS, respectively, n=15), water sorption and solubility (WS and SL, respectively - ISO 4049, n=5). Materials were made photopolymerizable by the addition of camphoroquinone/dimethylamine ethyl methacrylate. TEGDMA showed the highest DC, followed by BisEMA, UDMA and BisGMA, both at 10 min and at 24h (p<0.001). UDMA showed the highest rate of polymerization, followed by TEGDMA, BisEMA and BisGMA (H0=13.254, p<0.001). UDMA and TEGDMA presented similar FM, significantly higher (p<0.001) than BisEMA and BisGMA, which in turn present statistically similar values (p>0.001). For FS, UDMA presented the highest value (p<0.001), followed by TEGDMA, then by BisEMA and BisGMA, which were statistically similar (p>0.001). BisGMA showed the highest WS, and TEGDMA and BisEMA the lowest. UDMA was statistically similar to all (H0=16.074, p<0.001). TEGDMA presented the highest SL, followed by UDMA, BisGMA and BisEMA (p<0.001). The tested homopolymers presented different behaviors in terms of polymerization kinetics, flexural properties, water sorption and solubility. Therefore, the use of copolymers is justified in order to obtain high DC and mechanical properties, as well as good resistance to water degradation.

scholarly journals Correlation between the degree of conversion and the elution of leachable components from dental resin-based cements

2011 ◽  
Vol 76 (9) ◽  
pp. 1307-1323 ◽  
Author(s):  
Kosovka Obradovic-Djuricic ◽  
Vesna Medic ◽  
Marina Radisic ◽  
Mila Lausevic
Keyword(s):  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Cement Matrix ◽  
Dental Resin ◽  
Resin Cements ◽  
Triethylene Glycol Dimethacrylate ◽  
Urethane Dimethacrylate ◽  
Post Hoc ◽  
Composite Cements ◽  
One Way Anova

This study examined the possible correlation between the degree of conversion (DC) and the amount of substances eluted from three commercial cured resin-based cements. The DC of the various resin-based cements was measured by Raman spectroscopy, while the quantity of unreacted monomers released from the cement matrix (triethylene glycol dimethacrylate, TEGDMA, urethane dimethacrylate, UDMA, 2- hydroxyethyl methacrylate, HEMA and bis phenol A) was determined by high pressure liquid chromatography (HPLC). The obtained results, after multiple statistical evaluation (one way ANOVA, LSD post hoc test), showed no significant differences in the DC values between the resin cements. On the contrary, the results of the HPLC analysis depicted statistically significant differences between the three materials with respect to the amount of leached monomers. In addition, no correlation between the DC and the amount of eluted substances from the tested cured composite cements was found.

scholarly journals Novel Urethane-Dimethacrylate Monomers and Compositions for Use as Matrices in Dental Restorative Materials

2020 ◽  
Vol 21 (7) ◽  
pp. 2644 ◽  
Author(s):  
Izabela M. Barszczewska-Rybarek ◽  
Marta W. Chrószcz ◽  
Grzegorz Chladek
Keyword(s):  
Water Sorption ◽  
Water Solubility ◽  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Dental Composite ◽  
Polymerization Shrinkage ◽  
Dental Restorative Materials ◽  
Restorative Materials ◽  
Urethane Dimethacrylate ◽  
Dental Restorative

In this study, novel urethane-dimethacrylate monomers were synthesized from 1,3-bis(1-isocyanato-1-methylethyl)benzene (MEBDI) and oligoethylene glycols monomethacrylates, containing one to three oxyethylene groups. They can potentially be utilized as matrices in dental restorative materials. The obtained monomers were used to prepare four new formulations. Two of them were solely composed of the MEBDI-based monomers. In a second pair, a monomer based on triethylene glycol monomethacrylate, used in 20 wt.%, was replaced with triethylene glycol dimethacrylate (TEGDMA), a reactive diluent typically used in dental materials. For comparison purposes, two formulations, using typical dental dimethacrylates (bisphenol A glycerolate dimethacrylate (Bis-GMA), urethane-dimethacrylate (UDMA) and TEGDMA) were prepared. The monomers and mixtures were tested for the viscosity and density. The homopolymers and copolymers, obtained via photopolymerization, were tested for the degree of conversion, polymerization shrinkage, water sorption and solubility, hardness, flexural strength and modulus. The newly developed formulations achieved promising physico-chemical and mechanical characteristics so as to be suitable for applications as dental composite matrices. A combination of the MEBDI-based urethane-dimethacrylates with TEGDMA resulted in copolymers with a high degree of conversion, low polymerization shrinkage, low water sorption and water solubility, and good mechanical properties. These parameters showed an improvement in relation to currently used dental formulations.

scholarly journals The Effect of UDMA/TEGDMA Mixtures and Bioglass Incorporation on the Mechanical and Physical Properties of Resin and Resin-Based Composite Materials

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Laura C. Nicolae ◽  
Richard M. Shelton ◽  
Paul R. Cooper ◽  
Richard A. Martin ◽  
William M. Palin
Keyword(s):  
Physical Properties ◽  
Flexural Modulus ◽  
Triethylene Glycol ◽  
Resin Composites ◽  
Mechanical And Physical Properties ◽  
Three Point Bend Test ◽  
Point Bend ◽  
Urethane Dimethacrylate ◽  
45S5 Bioglass ◽  
The Impact

Incorporating Bioglass into dental composites may improve biocompatibility and aid tooth and bone tissue remineralisation. This study aimed to determine the impact of Bioglass and silica filler on the mechanical and physical properties of cured photopolymers. Hardness (Vickers microhardness test), flexural strength (FS), and flexural modulus (FM) (three-point bend test) of resins containing various urethane dimethacrylate (UDMA)/triethylene glycol dimethacrylate (TEGDMA) and bisphenol A-glycidyl methacrylate (bisGMA)/TEGDMA concentrations (20–80 mass%) were tested. Degree of conversion (DC), FS, and FM of resin composites containing nonsilanised irregular 45S5-Bioglass (50 μm; 5–40 mass%) and/or silanised silicate glass filler particulates (0.7 μm; 30–70 mass%) were tested. Data was analysed using one-way ANOVA. UDMA/TEGDMA resins exhibited increased hardness and FM compared with bisGMA/TEGDMA resins. Addition of Bioglass particles to 60/40 wt% UDMA/TEGDMA or bisGMA/TEGDMA resins may enable the development of new materials that exhibit higher or at least equivalent values of DC, FS, and FM compared with conventional resin composites.

The Combination of CQ-amine and TPO Increases the Polymerization Shrinkage Stress and Does Not Improve the Depth of Cure of Bulk-fill Composites

2019 ◽  
Vol 44 (5) ◽  
pp. 499-509
Author(s):  
MG Rocha ◽  
DCRS de Oliveira ◽  
MAC Sinhoreti ◽  
JF Roulet ◽  
AB Correr
Keyword(s):  
Near Infrared ◽  
Light Emitting Diode ◽  
Flexural Modulus ◽  
Degree Of Conversion ◽  
Light Transmittance ◽  
Volumetric Shrinkage ◽  
Shrinkage Stress ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Three Point Bend Test

SUMMARY Objectives: To evaluate the effect of combining camphorquinone (CQ) and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) on the depth of cure and polymerization shrinkage stress of bulk-fill composites. Methods and Materials: Experimental bulk-fill composites were produced containing equal molar concentrations of either CQ-amine or CQ-amine/TPO. The degree of in-depth conversion through each millimeter of a 4-mm-thick bulk-fill increment was evaluated by Fourier transform near-infrared microspectroscopy using a central longitudinal cross section of the increment of each bulk-fill composite (n=3). Light-transmittance of the multi-wave light-emitting diode (LED) emittance used for photoactivation (Bluephase G2, Ivoclar Vivadent) was recorded through every millimeter of each bulk-fill composite using spectrophotometry. The volumetric shrinkage and polymerization shrinkage stress were assessed using a mercury dilatometer and the Bioman, respectively. The flexural modulus was also assessed by a three-point bend test as a complementary test. Data were analyzed according to the different experimental designs (α=0.05 and β=0.2). Results: Up to 1 mm in depth, adding TPO to CQ-based bulk-fill composites increased the degree of conversion, but beyond 1 mm no differences were found. The light-transmittance of either wavelengths emitted from the multi-wave LED (blue or violet) through the bulk-fill composites were only different up to 1 mm in depth, regardless of the photoinitiator system. Adding TPO to CQ-based bulk-fill composites did not affect volumetric shrinkage but did increase the flexural modulus and polymerization shrinkage stress. Conclusion: Adding TPO to CQ-based bulk-fill composites did not increase the depth of cure. However, it did increase the degree of conversion on the top of the restoration, increasing the polymerization shrinkage stress.

scholarly journals Comparative Study on The Structure, Physical Properties and Hardness Indentation of a Bulk Fill & An Incremental Composite Resin Restorative Materials

2020 ◽  
Vol 17 ◽  
pp. 204-214
Author(s):  
Amira Elsherbeny ◽  
Rizk Mostafa Shalaby ◽  
Sayed Mohamed Ghorab
Keyword(s):  
Surface Roughness ◽  
Statistical Analysis ◽  
Vickers Microhardness ◽  
Great Influence ◽  
Mean Value ◽  
Degree Of Conversion ◽  
Resin Matrix ◽  
Bottom Surface ◽  
Depth Of Cure ◽  
Significant Difference

Totally 80 disk-shaped specimens of Filtek™ Bulk-Fill, 3M ESPE, and Filtek™ Z250 XT, 3M ESPE, were prepared by using split-Teflon mold (4mm×10mm). Specimen characterization XRD, Surface roughness, degree of conversion, Surface microhardness, and depth of cure of the specimens were evaluated after the specimens were stored in distilled water in darkness at 37°C for 24 h. Statistical analysis was done using t-test with a significance level at p<0.05. FiltekTM Z350 XT showed the highest mean value of Vickers microhardness either on top surface 94.94% or bottom surface 69.92% and recorded 76.51% while FiltekTM Bulk-Fill was 66.85% for depth of cure. Filtek bulk-fill recorded a lower mean value of 0.73 for Surface roughness than FiltekTM Z350 XT and the highest degree of conversion of 84.34%. Statistical analysis showed that there was a significant difference between the mean values for all tested results. Increasing the filler content proved to have ability to enhance some properties, specially the surface roughness. Incorporation of some structurally rigid monomers like Bis-DMA, UDMA, TEGDMA within the resin matrix have a great influence on the measured properties, including degree of conversion reached to 84.34%, depth of cure to a level of 76.51% and Vickers microhardness to 94.94%.

scholarly journals Characterization of Heat-Polymerized Monomer Formulations for Dental Infiltrated Ceramic Networks

2021 ◽  
Vol 11 (16) ◽  
pp. 7370
Author(s):  
Janine Tiu ◽  
Renan Belli ◽  
Ulrich Lohbauer
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Composite Structures ◽  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Reduced Viscosity ◽  
Heat Polymerization ◽  
Urethane Dimethacrylate

(1) Objectives: This work examined properties of dental monomer formulations of an aromatic dimethacylate (BisGMA), aliphatic urethane dimethacrylate (UDMA), and triethylene glycol dimethacrylate (TEGDMA). The monomers were combined in different ratio formulations and heat-polymerized containing the initiator benzoyl peroxide (BPO) specifically for the purpose of infiltration into polymer-infiltrated composite structures. (2) Methods: The monomers were combined in different weight ratios and underwent rheological analysis (viscosity and temperature dependence), degree of conversion, and mechanical properties (elastic modulus, hardness, fracture toughness). (3) Results: Rheological properties showed Newtonian behavior for monomers with a large dependence on temperature. The addition of BPO allowed for gelation in the range of 72.0–75.9 °C. Degree of conversion was found between 74% and 87% DC, unaffected by an increase of TEGDMA (up to 70 wt%). Elastic modulus, hardness, and fracture toughness were inversely proportional to an increase in TEGDMA. Elastic modulus and hardness were found slightly increased for UDMA versus BisGMA formulations, while fracture toughness ranged between 0.26 and 0.93 MPa·m0.5 for UDMA- and 0.18 and 0.68 MPa·m0.5 for BisGMA-based formulations. (4) Significance: Heat-polymerization allows for greater range of monomer formulations based on viscosity and degree of conversion when selecting for infiltrated composite structures. Therefore, selection should be based on mechanical properties. The measured data for fracture toughness combined with the reduced viscosity at higher UDMA:TEGDMA ratios favor such formulations over BisGMA:TEGDMA mixtures.

Properties of a New Nanofiber Restorative Composite

2019 ◽  
Vol 44 (1) ◽  
pp. 34-41 ◽  
Author(s):  
EM Yancey ◽  
W Lien ◽  
CS Nuttall ◽  
JA Brewster ◽  
HW Roberts ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
Testing Machine ◽  
Degree Of Conversion ◽  
Imaging Device ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Curing Shrinkage ◽  
Cylindrical Mold

SUMMARY A new nanofiber-reinforced hybrid composite (NovaPro Fill, Nanova) was recently introduced with reportedly improved mechanical properties. The purpose of this study was to compare the properties (flexural strength/modulus, degree of conversion [DC], depth of cure, and polymerization shrinkage) of the nanofiber composite to those of traditional hybrid composites (Filtek Z250, 3M ESPE; Esthet-X HD, Dentsply). To determine flexural strength and modulus, composite was placed in a rectangular mold, light-cured, stored for 24 hours, and then fractured in a universal testing machine. For degree of conversion, composite was placed in a cylindrical mold, light-cured, and stored for 24 hours. Measurements were made at the top and bottom surfaces using Fourier Transform Infrared Spectroscopy. To determine depth of cure, composite was placed in a cylindrical mold and light-cured. Uncured composite was scraped until polymerized resin was reached. Remaining composite was measured and divided by two. Polymerization shrinkage was determined by placing the composite material on a pedestal in a video-imaging device while light-curing. Shrinkage was determined after 10 minutes. Data were analyzed with one-way analysis of variance and Tukey post hoc test per property (α=0.05). Compared to Filtek Z250, NovaPro Fill had significantly lower flexural strength and modulus, greater volumetric shrinkage, and similar depth of cure, but greater top and bottom DC. Compared to Esthet-X HD, NovaPro Fill had similar flexural strength, shrinkage, and top and bottom DC, but significantly greater depth of cure and flexural modulus.

scholarly journals Improving the mechanical properties of polypropylene composites with coconut shell particles

2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flexural Modulus ◽  
Filler Particle ◽  
Tensile Modulus ◽  
Coconut Shell ◽  
Polypropylene Composites ◽  
Increase With Increase ◽  
Pp Composites ◽  
Shell Particles

Conventional inorganic fillers are widely used as fillers for polymer-based composites. Though, their processing difficulties and cost have demanded the quest for credible alternatives of organic origin like coconut shell fillers. Dried shells of coconut were burnt, ground, and sifted to sizes of 63, 150, 300, and 425 µm. The ground coconut shell particles (CSP) were used as a filler to prepare polypropylene (PP) composites at filler contents of 0% to 40% via injection melt blending process to produce PP composite sheets. The effect of the filler particle size on the mechanical properties was investigated. The decrease in the size of filler (CSP) was found to improve the yield strength, tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of PP by 8.5 MPa, 15.75 MPa, 1.72 GPa, 7.5 MPa, 100 MPa, and 10.5 HR for 63 µm at 40%, respectively. However, the elongation at break and modulus of resilience of the PP composites were seen to increase with increase in the filler size. Scanning electron microscope analysis showed that fillers with 63 µm particle size had the best distribution and interaction with the PP matrix resulting in enhanced properties.

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