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
2014 ◽  
Vol 73 (6) ◽  
pp. 474-480 ◽  
Author(s):  
Danijela Marovic ◽  
Tobias T. Tauböck ◽  
Thomas Attin ◽  
Vlatko Panduric ◽  
Zrinka Tarle

2019 ◽  
Vol 22 (3) ◽  
pp. 378-386
Author(s):  
Leticia Souza Lopes ◽  
Helio Rodrigues Sampaio Filho ◽  
Elisa Gomes Albuquerque ◽  
Chane Tardem ◽  
Mauro Sayão Miranda ◽  
...  

The objective of this study was to evaluate the alteration of the optical properties of bulk Fill resin-based composites after 2 years of simulated toothbrushing. Three high-viscosity bulk fill resin composites and one conventional sculptable resin composite (control) were analyzed. Five specimens of each resin composite were prepared, and roughness, color, translucency and gloss were evaluated initially and after one and two years of simulated toothbrushing. The specimens were submitted to electric simulated toothbrushing (14600 strokes/100g) using a commercially available toothbrush with soft fibers and toothpaste slurry in a proportion of 1:2 by weight. The brushing scheme was of 40 cycles per day (2 cycles per second / 280 cycles in a week). The optical properties and the roughness data were analyzed by a multifactor analysis of variance (MANOVA) and a Tukey post hoc test. The baseline and final values of Ra and Sa were submitted to linear regression analyses, all of which were performed at a significance level of p=0.05. Gloss and roughness presented statistical differences between the resin-time interactions in all composite resins. The gloss (72.5%) and roughness (89.4%) worsened significantly after brushing, but the authors didn’t find statistically significant differences when evaluating translucency and color. Based in the results, it could be concluded that the simulated brushing degraded the brightness and roughness of the used high-viscosity bulk fill composites.


e-Polymers ◽  
2018 ◽  
Vol 18 (5) ◽  
pp. 423-431 ◽  
Author(s):  
Xiaoqian Zhang ◽  
Wenli Guo ◽  
Yibo Wu ◽  
Yuwei Shang ◽  
Shuxin Li ◽  
...  

AbstractPoly(isobutylene-co-p-methylstyrene) (IB/p-MeSt) random copolymer is a new generation of polyisobutylene-based elastomer. The cationic copolymerization of IB with p-MeSt was thoroughly examined by using various initiating systems in [Hmim][NTf2] at −30°C. The effects of initiating systems and monomer feed ratio on the monomer conversion, molecular weight and copolymer composition are discussed. The polymers were characterized by 1H-nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and matrix-assisted laser desorption/ionization-time-of-flight-mass spectroscopy (MALDI-TOF-MS) to determine their chemical composition and molecular structure. The results show that high polarity, high viscosity and ionic environment of ionic liquids (ILs) influenced the copolymerization. The corresponding mechanism of cationic copolymerization in ILs is also proposed.


2014 ◽  
Vol 19 (4) ◽  
pp. 831-840 ◽  
Author(s):  
Z. Tarle ◽  
T. Attin ◽  
D. Marovic ◽  
L. Andermatt ◽  
M. Ristic ◽  
...  

2005 ◽  
Vol 19 (4) ◽  
pp. 272-277 ◽  
Author(s):  
Letícia Brandão ◽  
Gelson Luis Adabo ◽  
Luís Geraldo Vaz ◽  
José Roberto Cury Saad

The purpose of this study was to compare the compressive strengths and compressive fatigue limits of three posterior composite resins (Filtek P-60, Surefil and Prodigy Condensable) and a universal restorative composite (Z-100). Cylindrical specimens (8 mm in length x 4 mm in diameter) were used. The dynamic test was performed using the staircase method, and the ratio between compressive fatigue limit and compressive resistance was also calculated (n = 15). The compressive strength and compressive fatigue limit data were analyzed by Anova and Tukey’s test. The Z-100 composite demonstrated higher compression strength (307.20 MPa) than Surefil (266.93 MPa) and Prodigy Condensable (222.08 MPa). The resistance of Filtek P-60 (270.44 MPa) was similar to the resistances of Z-100 and Surefil, while Prodigy Condensable presented the lowest compressive strength. In the compressive fatigue limit tests, Filtek P-60 demonstrated a higher value (184.20 MPa) than Prodigy Condensable (155.50 MPa). Surefil (165.74 MPa) and Z-100 (161.22 MPa) presented limits similar to those of Filtek P-60 and Prodigy Condensable. The compressive fatigue limit/compressive strength ratio was 70.01% for Prodigy Condensable, 68.11% for Filtek P-60, 62.09% for Surefil and 52.48% for Z-100. It was concluded that the Z-100 universal composite was more sensitive to the dynamic test than the high viscosity materials.


Author(s):  
Ayça Sarialioğlu Güngör ◽  
Betül Aycan Uysal

The purpose of this study was to compare the shear bond strength (SBS) of four resin-based composite materials to a silicate-based cement using a “no-wait” universal bond with self-etch (SE) and etch-and-rinse (ER) modes. Acrylic blocks (n=80, 2mm depth, 5mm diameter central hole) were prepared. The holes were filled with BiodentineTM (BD) and divided into 4 main groups (n=20) according to the composite resin type used: Group FZ250: FiltekTM Z250 Universal Restorative (microhybrid), Group SDR: SDR Plus U Bulk Fill Flowable (low-viscosity bulk-fill), Group FBP: FiltekTM Bulk Fill Posterior (high-viscosity bulk-fill), Group EF: EsFlow™ Universal Flowable Composite (nanohybrid). A ‘no-wait’ universal bond (Clearfil Universal Bond Quick) was used for bonding application. Then each group was divided into 2 subgroups according to the etching mode applied (ER and SE). SBSs were measured and stereomicroscope was used to identify the failure modes. Selected samples of fracture surfaces were imaged by SEM. Tukey’s post-hoc and One-way ANOVA tests were used to analyze data. There were statistically significant differences among the composite groups (p<0.05). When SDR  showed the highest bond strength values in SE (17.13 ± 2.98 MPa) mode, FBP showed the lowest bond strength values in ER (8.89 ± 2.46 MPa) mode. The mean SBS was not different between the SE and ER modes (p> 0.05). The SBS of BD to the resin composites depends on the composite type but  application of the ‘no-wait’ universal bond in different etching modes is regardless of the SBS of BD to resin composites.


2021 ◽  
Vol 34 (2) ◽  
pp. 173-182
Author(s):  
Fabiana França ◽  
Jonathan Tenuti ◽  
Isabela Broglio ◽  
Lara Paiva ◽  
Roberta Basting ◽  
...  

The aim of this study was to compare low- and high-viscosity bulk-fill composites for Knoop microhardness (KHN), microtensile bond strength (MTBS) to dentin in occlusal cavities, and fracture strength (FS) in molars with mesialocclusal-distal restoration. Disk-shaped samples with different thicknesses (2 or 4 mm) of low-viscosity (SDR Flow, Dentsply) and high-viscosity bulk-fill composites (Filtek BulkFill, 3M ESPE; and Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) were prepared for top and bottom KHN analysis (n=10). MTBS to dentin and fracture pattern was evaluated in human molars with occlusal cavities restored with (n=10): conventional nanocomposite (Z350XT, 3M ESPE), low-viscosity (Filtek Bulk-fill Flow, 3M ESPE) or high-viscosity bulk-fill composites (Filtek BulkFill). The FS and fracture pattern of human molar with mesial-occlusal-distal restorations submitted or not to thermomechanical cycling were investigated (n=10) using: intact tooth (control), and restoration based on conventional microhybrid composite (Z250, 3M ESPE), low-viscosity (SDR Flow) or high-viscosity bulk-fill composites (Filtek BulkFill). The data were submitted to split-plot ANOVA (KHN), one-way ANOVA (MTBS), two-way ANOVA (FS) followed by Tukey’s test (α=0.05). For KHN, there was no significant difference for the resin composites between the top and bottom. For MTBS, no significant differences among the materials were detected; however, the low-viscosity composite presented lower frequency of adhesive failures. For FS, there was no significant difference between composites and intact tooth regardless of thermomechanical cycling. Low- and high-viscosity bulk-fill composites have comparable microhardness and microtensile bond strength when used in occlusal restorations. Likewise, the bulk-fill composites present similar fracture strength in molars with mesio-occlusal-distal restorations.


2019 ◽  
Vol 44 (6) ◽  
pp. 625-636 ◽  
Author(s):  
ER Cerda-Rizo ◽  
M de Paula Rodrigues ◽  
ABF Vilela ◽  
SSL Braga ◽  
LRS Oliveira ◽  
...  

SUMMARY Objective: To analyze the shrinkage stress, bonding interaction, and failure modes between different low-viscosity bulk fill resin composites and conventional resin composites produced by the same manufacturer or a high-viscosity bulk fill resin composite used to restore the occlusal layer in posterior teeth. Methods & Materials: Three low-viscosity bulk fill resin composites were associated with the conventional resin composites made by the same manufacturers or with a high-viscosity bulk fill resin composite, resulting in six groups (n=10). The bonding interaction between resin composites was tested by assessing the microshear bond strength (μSBS). The samples were thermocycled and were tested with 1-mm/min crosshead speed, and the failure mode was evaluated. The post-gel shrinkage (Shr) of all the resin composites was measured using a strain gauge (n=10). The modulus of elasticity (E) and the hardness (KHN) were measured using the Knoop hardness test. Two-dimensional finite element models were created for analyzing the stress caused by shrinkage and contact loading. The μSBS, Shr, E, and KHN data were analyzed using the Student t-test and one-way analysis of variance. The failure mode data were subjected to chi-square analysis (α=0.05). The stress distribution was analyzed qualitatively. Results: No significant difference was verified for μSBS between low-viscosity bulk fill resin composites and conventional or high-viscosity bulk fill composites in terms of restoring the occlusal layer (p=0.349). Cohesive failure of the low-viscosity bulk fill resin composites was the most frequent failure mode. The Shr, E, and KHN varied between low-viscosity and high-viscosity resin composites. The use of high-viscosity bulk fill resin composites on the occlusal layer reduced the stress at the enamel interface on the occlusal surface. Conclusions: The use of high-viscosity bulk fill resin composites as an occlusal layer for low-viscosity bulk fill resin composites to restore the posterior teeth can be a viable alternative, as it shows a similar bonding interaction to conventional resin composites as well as lower shrinkage stress at the enamel margin.


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