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Buruiana E.C.,Petru Poni Institute of Macromolecular Chemistry | Nechifor M.,Petru Poni Institute of Macromolecular Chemistry | Melinte V.,Petru Poni Institute of Macromolecular Chemistry | Buruiana T.,Petru Poni Institute of Macromolecular Chemistry | Prejmerean C.,Raluca Ripan Institute of Research in Chemistry
16th European Conference on Composite Materials, ECCM 2014 | Year: 2014

New dental ionomer compositions were prepared from diglycidyl methacrylate of bisphenol A (Bis-GMA) or an analogue of Bis-GMA (Bis-GMA-1), triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA), and a photocrosslinkable copolymer containing around 10 mol% methacrylate pendant groups. The photocurable polymer was obtained by functionalization with (N-methacryloyloxyethylcarbamoyl-N′-2-hydroxyethyl) urea of a ternary polymer synthesized by a radical polymerization of acrylic acid, itaconic acid and N-acryloyl-L-tryptophan. Light-curable cements, obtained by mixing the above organic compositions with filler (90 wt. % fluoroaluminosilicate/10 wt. % hydroxyapatite), exhibited flexural strength (FS) and compressive strength (CS) varying between 38.08 and 59.12 MPa (FS), and 107.58 and 162.13 MPa (CS), respectively. Source


Furtos G.,Raluca Ripan Institute of Research in Chemistry | Furtos G.,Babes - Bolyai University | Baldea B.,Victor Babes University of Medicine and Pharmacy Timisoara | Silaghi-Dumitrescu L.,Raluca Ripan Institute of Research in Chemistry | And 3 more authors.
Dental Materials Journal | Year: 2012

Digital radiography was used to measure the radiopacity of 18 resin cements to determine the influence of inorganic filler content on radiopacity. Four disk specimens (n=4) of each light-curing cement were digitally radiographed alongside an aluminum step wedge using an intraoral sensor (XIOS Plus, Sirona, Germany), and their mean gray value measured. Percentage of filler by weight was determined using an analytical combustion furnace. Data were statistically analyzed using one-way ANOVA and Tukey's test (α=0.05). All materials were more radiopaque than dentin and 12 materials were more radiopaque than enamel. Filler percentage ranged between 17.36 to 53.56 vol% and radiopacity between 1.02 to 3.40 mm Al. There were no statistically significant differences in inorganic filler percentage and radiopacity among the different shades of the same material (p>0.05), but the highest radiopacity was measured for the material which contained a higher percentage of filler. Source


Furtos G.,Raluca Ripan Institute of Research in Chemistry | Furtos G.,Babes - Bolyai University | Silaghi-Dumitrescu L.,Raluca Ripan Institute of Research in Chemistry | Moldovan M.,Raluca Ripan Institute of Research in Chemistry | Prejmerean C.,Raluca Ripan Institute of Research in Chemistry
Particulate Science and Technology | Year: 2012

Radiopacity is a requirement for dental restorative materials that permits evaluation of the integrity and adaptation over time to the restoration of the tooth structure. This work was to investigate amount of fillers and radiopacity of flowable resin composites using scanned radiograph images. Radiographs of samples (8mm diameter and 1mm thickness) were taken with a dental x-ray at 60kv, 7mA, for 0.32sec. exposure time, with a target-film distance at 40cm. After development, dental films (Kodak D-Speed) were scanned for digitalisation and average gray value was recorded for every sample using Image J software. Percentage of filler by weight and volume were assessed by combustion analysis. The filler percentages of the flowable composites determined was ranged from 52.26 to 69.74wt%. All materials investigated were more radiopaque than dentin and two materials were more radiopaque than enamel. The usage of low radiopaque materials should be avoided because it may lead to incorrect diagnosis. Future flowable resin composites are recommended to have higher radiopacity than dentin and perhaps ideally similar to or slightly higher than that of enamel for improved clinical detection. Digital imaging could be an alternative to transmission densitometry for the evaluation of the radiopacity of dental composites. © 2012 Copyright Taylor and Francis Group, LLC. Source


Furtos G.,Raluca Ripan Institute of Research in Chemistry | Furtos G.,Babes - Bolyai University | Tomoaia-Cotisel M.,Babes - Bolyai University | Prejmerean C.,Raluca Ripan Institute of Research in Chemistry
Particulate Science and Technology | Year: 2013

A series of new biomedical resin composites based on 2,2-bis[4-(2-hydroxy- 3-methacryloyloxypropoxy)-phenyl]propane/triethyleneglycol dimethacrylate resin reinforced with alkaline resistant (AR) glass fibers and BaSO4 powder in different ratios were prepared. The mechanical properties-that is, compressive strength (CS), flexural strength (FS), and flexural modulus (FM)-were determined. The results showed an increase of FS and FM and a slight decrease of CS with an increasing amount of glass fibers. Results revealed that CS increases in the following order: light-curing composites < self-curing composites < dual-curing composites. Structure of the resin composites were investigated by scanning electron microscopy of the fractured surface of composites after the FS test at different fiber amounts. Atomic force microscopy images of the polished surface of composites showed an increasing surface roughness with increasing filler content. © 2013 Copyright Taylor and Francis Group, LLC. Source


Furtos G.,Raluca Ripan Institute of Research in Chemistry | Furtos G.,Babes - Bolyai University | Tomoaia-Cotisel M.,Babes - Bolyai University | Garbo C.,Babes - Bolyai University | And 4 more authors.
Particulate Science and Technology | Year: 2013

Although total joint replacement surgery has become common in recent years, problems due to bacterial infection remain a significant complication following this procedure. One approach in our study was to obtain a self-cured bone cement based on hydroxyapatite with nanosilver (Hap-Ag) and ZrO2 and polymer matrix based on 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl] propane/triethyleneglycol dimethacrylate. New materials were tested for: in vitro silver release, compressive strength (CS), compressive modulus (CM), and radiopacity. In vitro silver release increased in time and depended of silver content in cement. The highest silver release was registered for the cement with 1.26 wt% silver content. The results reveal that the CS for bone cement was between 133.37 and 146.70 MPa and CM was between 1.68 and 1.82 GPa (p > 0.05). A slow increasing of CM was registered for samples with 1.5/1 powder/liquid ratio. Addition of nanosilver and ZrO2 increased radiopacity of experimental bone cement. © 2013 Copyright Taylor and Francis Group, LLC. Source

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