scholarly journals Characterization of Methacrylate-Based Resins Containing Methacryl-Polyhedral Oligomeric Silsesquioxanes (MA-POSS-8)

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1680
Author(s):  
Marietta Kreutz ◽  
Annette Wiegand ◽  
Bogna Stawarczyk ◽  
Nina Lümkemann ◽  
Marta Rizk
Keyword(s):  
Water Sorption ◽  
Artificial Saliva ◽  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Indentation Modulus ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Hybrid Layer ◽  
Control Degree ◽  
Oligomeric Silsesquioxane ◽  
Martens Hardness

The use of functionalized dental adhesives that might prevent degradation of the dentin hybrid layer has been proposed. The aim of the study was to characterize the physicochemical properties and the potential to induce mineral precipitation of methacrylate-based resins containing methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS-8). In total, six different compositions of resins based on bisphenol A glycerolate dimethacrylate (BisGMA, 40 to 60 wt.%), triethylene glycol dimethacrylate (TEGDMA, 5 to 35 wt.%) and 2-hydroxyethyl methacrylate (HEMA, 25 or 35 wt.%) were prepared and infiltrated with 5 wt.% MA-POSS-8. Unfilled resins served as control. Degree of conversion, viscosity, Martens hardness, indentation modulus, water sorption, and sol fraction were investigated. Polymerized specimens were examined by SEM/EDX for the presence of Ca/P precipitates after immersion in artificial saliva for 28 days at 37 °C. Statistical analysis was performed with two-way ANOVA and Tukey’s post-hoc test (p < 0.05). The degree of conversion ranged from 55.0 to 59.8% and was not affected by the addition of MA-POSS-8. Viscosity ranged from 60.0 to 422.3 mPa*s and was not affected by MA-POSS-8 except for one methacrylate-based resin with 60 wt.% BisGMA. Martens hardness and indentation modulus ranged from 161.3 to 138.1 N/mm2 and 4.2 to 3.9 kN/mm2 and were affected by MA-POSS-8 in only one resin (50 wt.% BisGMA, 25 wt.% TEGDMA, 25 wt.% HEMA). Water sorption was not affected by MA-POSS-8; sol fraction was below the detection limit. Formation of Ca/P precipitates was observed on all specimens of test and control groups. Material properties were not affected adversely by MA-POSS-8 except for slight differences in Martens hardness, indention modulus, viscosity in some groups. However, bioactive properties could not be improved by MA-POSS-8.

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 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 Degree of conversion and water sorption of self-adhesive and conventional flowable composites

2021 ◽  
Vol 19 ◽  
pp. e208556
Author(s):  
Ladan Ranjbar Omrani ◽  
Mahdi Abbasi ◽  
Fariba Motevasselian ◽  
Mohmad Amin Yektaei ◽  
Farhood Najafi
Keyword(s):  
Water Sorption ◽  
Artificial Saliva ◽  
Composite Resins ◽  
Degree Of Conversion ◽  
Flowable Composite ◽  
Significant Difference ◽  
Post Hoc ◽  
Flowable Composites ◽  
Vertise Flow

Aim: Self-adhesive flowable composite resins have been recently introduced to the market. Degree of conversion (DC) and water sorption (WS) are two important parameters affecting the properties of restorative materials. This study aimed to assess the DC and WS of a self-adhesive flowable composite resin in comparison with two conventional flowable composite resins. Methods: Vertise Flow (VF) self-adhesive and Tetric-N Flow (TF) and Grandio Flow (GF) conventional flowable composites were evaluated in this in vitro, experimental study. The DC (n=3) was determined by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The WS (n=7) was measured after 7 days of immersion in artificial saliva according to ISO 4049 specifications. Data were analyzed by one-way ANOVA and a post-hoc test (p<0.05). Results: VF showed the highest DC percentage (84.3%) followed by GF (72.79%) and TF (68.7%). The latter two had no significant difference (p=0.8). WS was the highest in VF (55.2 μg/mm3), and the two conventional flowable composites had a significant difference in WS (19.5 μg/mm3 in TF and 11 μg/mm3 in GF; p<0.001). Conclusions: Flowable composite resins had significant differences in DC and WS, and VF demonstrated the highest DC and WS.

scholarly journals The effect of polyhedral oligomeric silsesquioxanes (POSSs) incorporation in ethylene-propylene-diene-terpolymer (EPDM): a thermal study

2021 ◽  
Author(s):  
Ignazio Blanco ◽  
Traian Zaharescu
Keyword(s):  
Room Temperature ◽  
Thermal Characterization ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Dsc Analysis ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Ethylene Propylene ◽  
Oligomeric Silsesquioxane ◽  
Ethylene Propylene Diene Terpolymer ◽  
Dynamic Heating

AbstractA series of ethylene-propylene-diene-terpolymer (EPDM)/polyhedral oligomeric silsesquioxane (POSS) composites at different percentage of POSS were prepared and subjected to γ-irradiation. Both irradiated and non-irradiated EPDM and composites were investigated by the means of thermal analysis to verify if the presence of POSS molecules is able to reduce the oxidation level of free radicals generated during the degradation and to evaluate the effects of the irradiation. EPDM composites at 1, 3 and 5 mass% of POSS were thus degraded in a thermogravimetric (TG) balance in dynamic heating conditions (25–700 °C), in both inert and oxidative atmosphere by flowing nitrogen and air respectively. Thermal characterization was then completed by carrying out Differential Scanning Calorimetry (DSC) analysis from sub-ambient to better highlight the melting of the polymer and polymer composites occurring just above the room temperature. FTIR spectroscopy was also performed for the prepared samples to check the presence of the molecular filler in the composites and for the TG’s residue at 700 °C, in order to evaluate its nature. DSC and TGA parameters were detected and discussed to have information about the effect of the degradation’s environment, the effect of irradiation on polymer stabilization and the effect of POSS content in the polymer matrix.

scholarly journals Enhancing Toughness and Reducing Volumetric Shrinkage for Bis-GMA/TEGDMA Resin Systems by Using Hyperbranched Thiol Oligomer HMDI-6SH

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2817
Author(s):  
Biao Yu ◽  
Jingwei He ◽  
Sufyan Garoushi ◽  
Pekka K. Vallittu ◽  
Lippo Lassila
Keyword(s):  
Water Sorption ◽  
Water Solubility ◽  
Click Reaction ◽  
Raw Materials ◽  
Triethylene Glycol ◽  
Bending Test ◽  
Volumetric Shrinkage ◽  
Dental Resin ◽  
System A ◽  
Double Bond Conversion

In order to improve the toughness and reduce polymerization shrinkage of traditional bisphenol A-glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) based dental resin system, a hyperbranched thiol oligomer (HMDI-6SH) was synthesized via thiol-isocyanate click reaction using pentaerythritol tetra(3-mercaptopropionate (PETA) and dicyclohexylmethane 4,4′-diisocyanate (HMDI) as raw materials. Then HMDI-6SH was mixed with 1,3,5-Triallyl-1,3,5-Triazine-2,4,6(1H,3H,5H)-Trione (TTT) to prepare thiol-ene monomer systems, which were added into Bis-GMA/TEGDMA resins with different mass ratio from 10 wt% to 40 wt% to serve as anti-shrinking and toughening agent. The physicochemical properties of these thiol-ene-methacrylate ternary resins including functional groups conversion, volumetric shrinkage, flexural properties, water sorption, and water solubility were evaluated. The results showed that the incorporation of HMDI/TTT monomer systems into Bis-GMA/TEGDMA based resin could improve C=C double bond conversion from 62.1% to 82.8% and reduced volumetric shrinkage from 8.53% to 4.92%. When the mass fraction of HMDI/TTT monomer systems in the resins was no more than 20 wt%, the flexural strength of the resin was higher or comparable to Bis-GMA/TEGDMA based resins (p > 0.05). The toughness (it was measured from the stress–strain curves of three-point bending test) of the resins was improved. Water sorption and water solubility tests showed that the hydrophobicity of resin was enhanced with increasing the content of thioester moiety in resin.

scholarly journals Hydrophobically Modified Isosorbide Dimethacrylates as a Bisphenol-A (BPA)-Free Dental Filling Material

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2139
Author(s):  
Bilal Marie ◽  
Raymond Clark ◽  
Tim Gillece ◽  
Seher Ozkan ◽  
Michael Jaffe ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flexural Strength ◽  
Bisphenol A ◽  
Water Sorption ◽  
Triethylene Glycol ◽  
Filling Material ◽  
Hydrophobically Modified ◽  
Free Replacement

A series of bio-based hydrophobically modified isosorbide dimethacrylates, with para-, meta-, and ortho- benzoate aromatic spacers (ISBGBMA), are synthesized, characterized, and evaluated as potential dental restorative resins. The new monomers, isosorbide 2,5-bis(4-glyceryloxybenzoate) dimethacrylate (ISB4GBMA), isosorbide 2,5-bis(3-glyceryloxybenzoate) dimethacrylate (ISB3GBMA), and isosorbide 2,5-bis(2-glyceryloxybenzoate) dimethacrylate (ISB2GBMA), are mixed with triethylene glycol dimethacrylate (TEGDMA) and photopolymerized. The resulting polymers are evaluated for the degree of monomeric conversion, polymerization shrinkage, water sorption, glass transition temperature, and flexural strength. Isosorbide glycerolate dimethacrylate (ISDGMA) is synthesized, and Bisphenol A glycerolate dimethacrylate (BisGMA) is prepared, and both are evaluated as a reference. Poly(ISBGBMA/TEGDMA) series shows lower water sorption (39–44 µg/mm3) over Poly(ISDGMA/TEGDMA) (73 µg/mm3) but higher than Poly(BisGMA/TEGDMA) (26 µg/mm3). Flexural strength is higher for Poly(ISBGBMA/TEGDMA) series (37–45 MPa) over Poly(ISDGMA/TEGDMA) (10 MPa) and less than Poly(BisGMA/TEGDMA) (53 MPa) after immersion in phosphate-buffered saline (DPBS) for 24 h. Poly(ISB2GBMA/TEGDMA) has the highest glass transition temperature at 85 °C, and its monomeric mixture has the lowest viscosity at 0.62 Pa·s, among the (ISBGBMA/TEGDMA) polymers and monomer mixtures. Collectively, this data suggests that the ortho ISBGBMA monomer is a potential bio-based, BPA-free replacement for BisGMA, and could be the focus for future study.

scholarly journals Influence of Hydroxyapatite Nanospheres in Dentin Adhesive on the Dentin Bond Integrity and Degree of Conversion: A Scanning Electron Microscopy (SEM), Raman, Fourier Transform-Infrared (FTIR), and Microtensile Study

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2948
Author(s):  
Rana S Al-Hamdan ◽  
Basil Almutairi ◽  
Hiba F Kattan ◽  
Noura A. Alsuwailem ◽  
Imran Farooq ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Study Groups ◽  
Degree Of Conversion ◽  
Hybrid Layer ◽  
X Ray ◽  
And Control ◽  
Scanning Electron

An experimental adhesive incorporated with different nano-hydroxyapatite (n-HA) particle concentrations was synthesized and analyzed for dentin interaction, micro-tensile bond strength (μTBS), and degree of conversion (DC). n-HA powder (5 wt % and 10 wt %) were added in adhesive to yield three groups; gp-1: control experimental adhesive (CEA, 0 wt % HA), gp-2: 5 wt % n-HA (HAA-5%), and gp-3: 10 wt % n-HA (HAA-10%). The morphology of n-HA spheres was evaluated using Scanning Electron Microscopy (SEM). Their interaction in the adhesives was identified with SEM, Energy-Dispersive X-ray (EDX), and Micro-Raman spectroscopy. Teeth were sectioned, divided in study groups, and assessed for μTBS and failure mode. Employing Fourier Transform-Infrared (FTIR) spectroscopy, the DC of the adhesives was assessed. EDX mapping revealed the occurrence of oxygen, calcium, and phosphorus in the HAA-5% and HAA-10% groups. HAA-5% had the greatest μTBS values followed by HAA-10%. The presence of apatite was shown by FTIR spectra and Micro-Raman demonstrated phosphate and carbonate groups for n-HA spheres. The highest DC was observed for the CEA group followed by HAA-5%. n-HA spheres exhibited dentin interaction and formed a hybrid layer with resin tags. HAA-5% demonstrated superior μTBS compared with HAA-10% and control adhesive. The DC for HAA-5% was comparable to control adhesive.

Tuning “thiol-ene” reactions toward controlled symmetry breaking in polyhedral oligomeric silsesquioxanes

2014 ◽  
Vol 5 (3) ◽  
pp. 1046-1053 ◽  
Author(s):  
Yiwen Li ◽  
Kai Guo ◽  
Hao Su ◽  
Xiaopeng Li ◽  
Xueyan Feng ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Building Blocks ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Ene Reactions ◽  
Oligomeric Silsesquioxane

A facile method toward polyhedral oligomeric silsesquioxane-based nano-building blocks with controlled symmetry breaking was reported by using thiol-ene chemistry.

Poly(styrene-b-butadiene-b-styrene)-Dye-Coupled Polyhedral Oligomeric Silsesquioxanes

2010 ◽  
Vol 123-125 ◽  
pp. 169-172
Author(s):  
Steven Spoljaric ◽  
Robert A. Shanks
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Block Copolymer ◽  
Exponential Function ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Element Model ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Creep And Recovery ◽  
Oligomeric Silsesquioxane ◽  
Colour Coordinates

Dye-coupled polyhedral oligomeric silsesquioxane (POSS) were prepared and the coloured POSS particles were ultrasonically solution dispersed in poly(styrene-b-butadiene-b-styrene) (SBS). POSS molecules contained either isobutyl or phenyl groups to provide selective compatibility with either the soft (butadiene) or hard (styrene) phase within the block copolymer. The composition and thermal stability were characterised using thermogravimetry. Colour coordinates were measured. Tensile mechanical properties, creep and recovery were determined. Creep was modeled using the 4-element model of Maxwell and Kelvin-Voigt, while recovery correlated with the stretched-exponential function of Kohlrausch, Williams and Watts.

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