scholarly journals Effect of light activation time and irradiance of multi-peak light curing unit on flowable and high viscosity bulk fill resin composites

2020 ◽  
Author(s):  
Raissa Deus
2012 ◽  
Vol 37 (4) ◽  
pp. 380-385 ◽  
Author(s):  
NC Lawson ◽  
D Cakir ◽  
P Beck ◽  
L Ramp ◽  
JO Burgess

SUMMARY Objective Recent studies confirmed that resin-modified glass ionomers (RMGIs) set on the basis of two competing mechanisms, an acid-base reaction and a light-activated resin polymerization. This study evaluated the effect of the setting mechanism on bond strength by measuring the shear bond strength of three RMGIs to dentin with and without light activation. Methods Sixty human molars were ground to midcoronal dentin and randomly divided into six even groups: 1) Ketac Nano (KN), 2) KN without light cure (woLC), 3) Fuji Filling LC (FF), 4) FF woLC, 5) Fuji II LC (FII), and 6) FII woLC. The dentin surfaces of the specimens were conditioned/primed according to the manufacturers' instructions. A 1.54-mm diameter plastic tube was filled with RMGI material and affixed to the dentin surface. Groups 1, 3, and 5 were light cured for 20 seconds, and groups 2, 4, and 6 were immediately placed in a damp dark box with no light curing at 37°C for 24 hours. Shear bond strength testing was performed in an Instron device at 1 mm/min. Data were analyzed with a one-way analysis of variance (ANOVA) and Tukey/Kramer test (α=0.05). Results Mean ± standard deviation shear bond strength values (MPa) are: 7.1 ± 4.2 (KN), 11.7 ± 3.9 (FF), 10.2 ± 3.2 (FF woLC), 12.5 ± 5.1 (FII), and 0.3 ± 0.4 (FII woLC). Two KN, all KN woLC, and seven FII woLC specimens debonded before testing. Tukey/Kramer analysis revealed no significant differences in bond strength between the three light-cured RMGIs. KN and FII showed significantly lower bond strength without light cure, but no significant difference was observed between FF and FF woLC. Conclusions The results of this study strongly suggest that light activation is necessary to obtain optimal bond strength between RMGI and dentin. FF may contain components that chemically activate resin polymerization. Clinically, KN and FII need to be light cured after placement of these RMGIs.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Luca Marigo ◽  
Giuseppina Nocca ◽  
Giulia Fiorenzano ◽  
Cinzia Callà ◽  
Raffaella Castagnola ◽  
...  

The aim of this study was to evaluate the effect of light-curing protocols on two modern resin composites using different air-inhibition coating strategies. This was accomplished by assessing the amount of monomer elution, surface microhardness, and composite discoloration in different storage conditions. A total of 120 specimens were prepared using Filtek Supreme XTE (3M ESPE, Seefeld, Germany) and CeramX Universal (Dentsply DeTrey, Konstanz, Germany). Specimens were light-cured in air as per manufacturer’s instructions or in the absence of oxygen. This latter condition was achieved using three different approaches: (i) transparent polyester strip; (ii) glycerin; (iii) argon gas. Specimens were assessed for release of monomers, Vickers hardness, and discoloration after storage in different solutions. The results were analyzed with ANOVA one-way test followed by Student-Newman-Keuls test. Moreover, multiple comparisons of means were performed using the Student t-test (p<0.05). The amount of monomers released from the tested specimens was very low in all conditions. The presence of oxygen induced some decrease in microhardness. The highest discoloration values, for both materials, were obtained after ageing in red wine. In case finish and polish procedures are awkward to achieve in posteriors composite restoration, light-curing in the absence of oxygen should be considered, especially when performing composite restoration in esthetic areas.


2007 ◽  
Vol 32 (5) ◽  
pp. 443-450 ◽  
Author(s):  
M. G. Brackett ◽  
W. W. Brackett ◽  
W. D. Browning ◽  
F. A. Rueggeberg

Clinical Relevance The selection of light curing unit (quartz-tungsten-halogen or blue light-emitting diode), composite classification and shade have an influence on the amount of residual yellow after photocuring and, in some combinations, the color difference may be visually detectable.


Author(s):  
João Felipe Besegato ◽  
Eduardo Inocente Jussiani ◽  
Avacir Casanova Andrello ◽  
Ricardo Vignoto Fernandes ◽  
Fabio Martins Salomão ◽  
...  

Author(s):  
C Kucukesmen ◽  
A Usumez ◽  
BC Uludag ◽  
B Gunduz ◽  
CH Kucukesmen ◽  
...  

2019 ◽  
Vol 64 (11) ◽  
pp. 1007-1014
Author(s):  
Tong XU ◽  
◽  
Jia-Hui ZHANG ◽  
Zhao-Ying LIU ◽  
Xuan LI ◽  
...  

2020 ◽  
Author(s):  
RQ Ramos ◽  
RR Moraes ◽  
GC Lopes

Clinical Relevance The use of multipeak LED light-curing guarantees efficiency on light activation of Ivocerin-containing light-cured resin cement.


2020 ◽  
Vol 45 (5) ◽  
pp. 496-505
Author(s):  
CS Sampaio ◽  
PG Pizarro ◽  
PJ Atria ◽  
R Hirata ◽  
M Giannini ◽  
...  

Clinical Relevance Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro–computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS. Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes. Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.


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.


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