Monomer conversion and shrinkage force kinetics of low-viscosity bulk-fill resin composites

2014 ◽  
Vol 73 (6) ◽  
pp. 474-480 ◽  
Author(s):  
Danijela Marovic ◽  
Tobias T. Tauböck ◽  
Thomas Attin ◽  
Vlatko Panduric ◽  
Zrinka Tarle
Keyword(s):  
Monomer Conversion ◽  
Resin Composites ◽  
Low Viscosity ◽  
Shrinkage Force ◽  
Kinetics Of

scholarly journals Pre-heating of high-viscosity bulk-fill resin composites: Effects on shrinkage force and monomer conversion

2015 ◽  
Vol 43 (11) ◽  
pp. 1358-1364 ◽  
Author(s):  
Tobias T. Tauböck ◽  
Zrinka Tarle ◽  
Danijela Marovic ◽  
Thomas Attin
Keyword(s):  
Monomer Conversion ◽  
High Viscosity ◽  
Resin Composites ◽  
Shrinkage Force

scholarly journals Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 474
Author(s):  
Ioannis S. Tsagkalias ◽  
Alexandra Loukidi ◽  
Stella Chatzimichailidou ◽  
Constantinos E. Salmas ◽  
Aris E. Giannakas ◽  
...  
Keyword(s):  
Essential Oil ◽  
Radical Polymerization ◽  
Food Packaging ◽  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Hydroxyl Groups ◽  
Modified Montmorillonite ◽  
Kinetics Of

The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT.

Polymerization shrinkage-stress kinetics of resin-composites

2014 ◽  
Vol 30 ◽  
pp. e57
Author(s):  
H. Al-Sunbul ◽  
N. Silikas ◽  
D.C. Watts
Keyword(s):  
Shrinkage Stress ◽  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Kinetics Of

scholarly journals Influence of Bulk-Fill Composites, Polimerization Modes, and Remaining Dentin Thickness on Intrapulpal Temperature Rise

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Serdar Akarsu ◽  
Sultan Aktuğ Karademir
Keyword(s):  
Temperature Rise ◽  
Variance Analysis ◽  
Resin Composites ◽  
Application Time ◽  
Led Light ◽  
Low Viscosity ◽  
Single Tooth ◽  
Light Curing ◽  
Dentin Thickness

Objectives. The aim of this study was to compare the effects of different bulk-fill resin composites, polimerization modes, and the thickness of remaining dentin on the increase of intrapulpal temperature. Methods. Human-extracted upper premolar teeth (n = 10) were used to design a single-tooth model with remaining dentin thicknesses of 1 mm and 0.5 mm. Estelite Bulk-fill Flow (Tokuyama, Japan), Surefil SDR™ Flow (Dentsply Caulk, Brazil), Filtek Bulk-Fill Posterior (3M, USA), and SonicFill™ 2 Bulk-fill (Kerr, USA) composites were applied according to the manufacturer’s instructions. The standard and high modes of a light emitted diode (LED) light curing unit (LCU) (VALO™ Utradent, USA), were used for polymerization. In order to mimic the in vivo conditions of pulpal circulation, digital flowmetry (SK-600II, SK Medical, China) was used. Intrapulpal temperature rise was measured using K type thermocoupling (CEM DT 610B, Robosem Engineering, China). Data were analyzed using three-way variance analysis (ANOVA) and the independent t-test. Results. No significant statistical differences in intrapulpal temperature rise between low viscosity bulk-fill composites (SDR and Estelite) were found. The lowest intrapulpal temperature rise was found in groups which used the Filtek Bulk-fill composite. Decreases in the remaining dentin thickness increased the intrapulpal temperature rise. Significance. This study demonstrated that remaining dentin thickness, filler ratio of bulk-fill composites, and power and application time of the LED-LCU may affect intrapulpal temperature rise.

Polymerization Shrinkage Stress Kinetics and Related Properties of Bulk-fill Resin Composites

2014 ◽  
Vol 39 (4) ◽  
pp. 374-382 ◽  
Author(s):  
HM El-Damanhoury ◽  
JA Platt
Keyword(s):  
Standard Procedure ◽  
Stress Rate ◽  
Shrinkage Stress ◽  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Significance Level ◽  
Microhardness Data ◽  
Knoop Microhardness ◽  
Kinetics Of ◽  
Fill Materials

SUMMARY The present study assessed the polymerization shrinkage stress kinetics of five low-shrinkage light-cured bulk-fill resin composites: Surefil SDR flow (SF, Dentsply), Tetric EvoCeram Bulkfil (TE, Ivoclar Vivadent), Venus Bulk Fill (VB, Heraeus Kulzer), x-tra fil (XF, Voco), and experimental bulk fill (FB, 3M ESPE). Filtek Z250 (FZ, 3M ESPE) was used as a control. Real-time shrinkage stress of investigated composites was measured using a tensometer; maximum shrinkage stress, stress rate (Rmax), and time to reach maximum stress rate (tmax) were recorded. Flexural strength and modulus were measured using a standard procedure, and curing efficiency of 4-mm long specimens was determined using bottom/top percentage Knoop microhardness. Data were analyzed using one-way analysis of variance and Bonferroni multiple range tests at a significance level of α=0.05. Results of shrinkage stress, Rmax, and tmax of all bulk-fill materials were significantly lower (p<0.05) than those of the control except for XF. All tested bulk-fill materials were able to achieve acceptable curing efficiency (≥80% bottom/top percentage) at 4-mm depth. In conclusion, this study reports a significant reduction in polymerization shrinkage stress while maintaining comparable curing efficiency at 4 mm for some bulk-fill composites and supports their potential use in posterior clinical situations.

Viscosity and thermal kinetics of 10 preheated restorative resin composites and effect of ultrasound energy on film thickness

2020 ◽  
Vol 36 (10) ◽  
pp. 1356-1364
Author(s):  
Rogério L. Marcondes ◽  
Verônica P. Lima ◽  
Fabíola J. Barbon ◽  
Cristina P. Isolan ◽  
Marco A. Carvalho ◽  
...  
Keyword(s):  
Film Thickness ◽  
Resin Composites ◽  
Thermal Kinetics ◽  
Ultrasound Energy ◽  
Kinetics Of

Kinetics of Isoprenepolymerization Initiated with TiCl4—Trialkyl Aluminum

1960 ◽  
Vol 33 (3) ◽  
pp. 696-698
Author(s):  
S. E. Bresler ◽  
M. I. Mosevitskiĭ
Keyword(s):  
Active Sites ◽  
Reaction Medium ◽  
Heat Evolution ◽  
Polymerization Reaction ◽  
Reaction Conditions ◽  
Low Viscosity ◽  
Rate Of Polymerization ◽  
Rate Of Reaction ◽  
Entire Experiment ◽  
Kinetics Of

Abstract For the study of the mechanism of polymerization by means of complexes of aluminum organic compounds with titanium chlorides, data on the kinetics of polymerization is of great interest. Up to the present time, the rate of polymerization of propylene has been studied but the interpretation of the kinetic data is difficult because the polymer, which is practically insoluble in the reaction medium, entraps the catalyst resulting in a rate of reaction which is dependent on the diffusion of monomer through the polymer to the active sites. In this work the polymerization of isoprene, which yields polymers soluble in the monomer, in saturated hydrocarbons and in benzene, was studied. The rate of the polymerization reaction was measured by the thermal effect in a calorimeter consisting of a 3.5 1. Dewar flask, with a lid, immersed in a thermostated air bath maintained at approximately the temperature of the reaction. Low viscosity spindle oil, heated to the temperature of the reaction (about 32°), served as the calorimeter fluid. The ampoule holder extended outside of the calorimeter and was connected to a shaking apparatus. The ampoule was divided by a thin partition into two sections each holding 45–50 cc. Into one section previously purified monomers and solvent were distilled. The other section was filled with catalyst components from a Shlenk container. The change in temperature of the calorimeter was determined with a Beckman thermometer with an accuracy of 0.01 °. When the temperature of the calorimeter containing the ampoule remained constant to within 0.01–0.02° for 30–40 minutes, the shaking apparatus was connected and the partition was broken with a striker. Intensive shaking was continued during the entire experiment resulting in mixing of the reaction mixture and of the calorimeter fluid. The rate of reaction was determined by the rate of heat evolution ; in other words, by the temperature rise in the calorimeter. For a rise of 0.1–0.5° the reaction conditions remained practically isothermal. This rise permits the kinetics of the reaction to be observed with sufficient accuracy. Adiabaticity of the calorimeter and the effect of mechanical heat were controlled in separate experiments.

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