Effect of Photoinitiator Combinations on Hardness, Depth of Cure, and Color of Model Resin Composites

2015 ◽  
Vol 27 ◽  
pp. S41-S48 ◽  
Author(s):  
Vinícius Esteves Salgado ◽  
Mila Metri Borba ◽  
Larissa Maria Cavalcante ◽  
Rafael Ratto de Moraes ◽  
Luis Felipe Schneider
Keyword(s):  
Resin Composites ◽  
Depth Of Cure ◽  
Hardness Depth

scholarly journals Curing Depth of Light-activated Nanofiller containing Resin Composites

2012 ◽  
Vol 3 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Werner J Finger ◽  
Masafumi Kanehira ◽  
Yasuyuki Araki ◽  
Takehiko Wada ◽  
Andreas Utterodt ◽  
...  
Keyword(s):  
Crosslink Density ◽  
Mechanical Characteristics ◽  
Polynomial Regression ◽  
Knoop Hardness ◽  
Resin Composites ◽  
Depth Level ◽  
Depth Of Cure ◽  
Micro Raman Spectroscopy ◽  
Parallel Lines ◽  
Order Polynomial

ABSTRACT Objective To compare the depth of cure of nanofiller containing with conventional resin composites. Materials and methods Five nanofilled and nanohybrid composites were investigated and compared with a microfilled and a microhybrid reference, using the ISO 4049 scraping test, Knoop hardness (KHN) and DC profiling. Specimens from all materials (shade A3) were activated with the same LED light source for 20s. KHN (0.25N/15s) of three specimens each, produced in split molds was measured after 24 hours dark storage on sections perpendicular to the irradiated surface at 250 µm distance along the center line and two parallel lines, 0.5 mm apart, to a depth of 3 mm. Mean KHNs of the three neighboring indentations at each level were calculated. Degree of conversion (DC) was determined on specimens as mentioned above using micro-Raman spectroscopy at 125 µm distance with three measurements at each depth level. Results The depth of cure of all materials was >2 mm when determined according to the ISO test. KHN and DC data followed second order polynomial regression lines (r2 > 0.70; p < 0.001). At 2 mm depth, the KHN of six resin composites was ≤80% of the top KHN whereas the DC of all materials was ≥86% of the maximum DC at the irradiated surface. Conclusion The ISO scraping test overemphasizes the attainable depth of cure, when compared with 80% of top KHN as arbitrarily defined curing depth. KHNs reflect the crosslink density of the polymer, whereas DC additionally includes double bond conversions not contributing to enhancement of mechanical characteristics. How to cite this article Kanehira M, Araki Y, Finger WJ, Wada T, Utterodt A, Komatsu M. Curing Depth of Light-activated Nanofiller containing Resin Composites. World J Dent 2012;3(2): 119-125.

Methacrylate- and silorane-based composite restorations: Hardness, depth of cure and interfacial gap formation as a function of the energy dose

2011 ◽  
Vol 27 (11) ◽  
pp. 1162-1169 ◽  
Author(s):  
Paulo Henrique Perlatti D’Alpino ◽  
Janaina Bechtold ◽  
Priscila Jaques dos Santos ◽  
Roberta Caroline Bruschi Alonso ◽  
Vinicius Di Hipólito ◽  
...  
Keyword(s):  
Gap Formation ◽  
Depth Of Cure ◽  
Composite Restorations ◽  
Interfacial Gap ◽  
Hardness Depth ◽  
Energy Dose

Bulk-fill resin composites: Mechanical properties vs depth of cure

2016 ◽  
Vol 32 ◽  
pp. e20-e21
Author(s):  
R.B.W. Lima ◽  
F. Murillo-Gómez ◽  
C.G. Sartori ◽  
M.F. De Goes
Keyword(s):  
Mechanical Properties ◽  
Resin Composites ◽  
Depth Of Cure

scholarly journals Depth of cure, flexural properties and volumetric shrinkage of low and high viscosity bulk-fill giomers and resin composites

2017 ◽  
Vol 36 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Akimasa TSUJIMOTO ◽  
Wayne W. BARKMEIER ◽  
Toshiki TAKAMIZAWA ◽  
Mark A. LATTA ◽  
Masashi MIYAZAKI
Keyword(s):  
High Viscosity ◽  
Volumetric Shrinkage ◽  
Flexural Properties ◽  
Resin Composites ◽  
Depth Of Cure

Polymerization Shrinkage and Depth of Cure of Bulk-Fill Resin Composites and Highly Filled Flowable Resin

2015 ◽  
Vol 40 (2) ◽  
pp. 172-180 ◽  
Author(s):  
J-H Jang ◽  
S-H Park ◽  
I-N Hwang
Keyword(s):  
Surface Hardness ◽  
Bottom Surface ◽  
Shrinkage Stress ◽  
Internal Diameter ◽  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Custom Made ◽  
Polymerization Behavior ◽  
The Mean

SUMMARY The aim of this study was to evaluate the polymerization behavior and depth of cure (DOC) of recently introduced resin composites for posterior use: highly filled flowable composite and composites for bulk fill. A highly filled flowable (G-aenial Universal Flo [GUF]), two bulk-fill flowables (Surefil SDR Flow [SDR] and Venus Bulk fill [VBF]), and a bulk-fill nonflowable composite (Tetric N-Ceram Bulk fill [TBF]) were compared with two conventional composites (Tetric Flow [TF], Filtek Supreme Ultra [FS]). Linear polymerization shrinkage and polymerization shrinkage stress were each measured with custom-made devices. To evaluate DOC, the composite specimen was prepared using a mold with a hole of 4 mm depth and 4 mm internal diameter. The hole was bulk filled with each of the six composites and light cured for 20 seconds, followed by 24 hours of water storage. The surface hardness was measured on the top and the bottom using a Vickers microhardness (HV) indenter. The linear polymerization shrinkage of the composite specimens after photo-initiation decreased in the following order: TF and GUF &gt; VBF &gt; SDR &gt; FS and TBF (p&lt;0.05). The polymerization shrinkage stress of the six composite groups decreased in the following order: GUF &gt; TF and VBF &gt; SDR &gt; FS and TBF (p&lt;0.05). The mean bottom surface HV of SDR and VBF exceeded 80% of the top surface HV (HV-80%). However, the bottom of GUF and TBF failed to reach HV-80%. A highly filled flowable (GUF) revealed limitations in polymerization shrinkage and DOC. Bulk-fill flowables (SDR and VBF) were properly cured in 4-mm bulk, but they shrank more than the conventional nonflowable composite. A bulk-fill nonflowable (TBF) showed comparable shrinkage to the conventional nonflowable composite, but it was not sufficiently cured in the 4-mm bulk.

Dental Resin Composites with Enhanced Properties Bycommercial Silica Particles as Fillers

2015 ◽  
Vol 815 ◽  
pp. 336-341
Author(s):  
Shuang Bao ◽  
Rui Li Wang ◽  
Bin Sun ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu
Keyword(s):  
Mechanical Properties ◽  
Resin Composite ◽  
Flexural Modulus ◽  
Silica Particles ◽  
Component Ratio ◽  
Resin Composites ◽  
Dental Resin ◽  
Depth Of Cure ◽  
Dental Resin Composites ◽  
Enhanced Properties

To explore the preparation of novel dental resin composites with enhanced properties, two commercial silica particles with sizes of around 1μm and 40 nm were chosen as inorganic fillers, and firstly surface functionalized by 3-methacryloxypropyltrimethoxysilane (γ-MPS) to incorporate cross-linkable vinyl groups onto the surface of fillers. Then the modified fillers were blended with organic monomers, bisphenolAdiglycidyldimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA), to fabricate the resin compositeswith a three-roll mixer.Resin composites with various weight percentage of fillers and component ratio of microparticle and nanoparticle were prepared. Surface functionalization of silica particles was characterized by fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), and mechanical properties degree of conversion, and depth of cure of the resultant resin composites were investigated byuniversal testing machineand FTIR. The results indicated that surface modification of silica particles was successful and the surface organic contents were 3.29% and 4.34%, respectively. Among the studied resin composites, the resin composite with 75 wt.% silica particles (59 wt.% microparticles and 16 wt.% nanoparticles) presented the highest value of depth of cure (5.52 ± 0.07 mm), and optimum mechanical properties such as flexural strength (149.8 ± 3.3 MPa), flexural modulus (13.8 ± 0.06 GPa), compressive strength (340.6 ± 8.3 MPa) and Vicker’smicrohardness (78.26 ± 2.45 HV). The study of dental resin composites fabricated from commercial silica particles with excellent properties might provide a new sight for realizing the preparation of this kind of dental resin composites in an industrial scale.

scholarly journals Shrinkage Stress and Temperature Variation in Resin Composites Cured via Different Photoactivation Methods: Insights for Standardisation of the Photopolymerisation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2065
Author(s):  
Guilherme dos Santos Sousa ◽  
Gabriel Felipe Guimarães ◽  
Edilmar Marcelino ◽  
José Eduardo Petit Rodokas ◽  
Arilson José de Oliveira Júnior ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Temperature Variation ◽  
Resin Composite ◽  
Smartphone App ◽  
Shrinkage Stress ◽  
Resin Composites ◽  
Pulse Delay ◽  
Depth Of Cure ◽  
Practical Applications ◽  
Soft Start

The literature has shown that there is no consensus regarding the best resin composite photoactivation protocol. This study evaluated the efficiency of the conventional, soft-start, pulse-delay and exponential protocols for photoactivation of resin composites in reducing the shrinkage stress and temperature variation during the photopolymerisation. The photoactivation processes were performed using a photocuring unit and a smartphone app developed to control the irradiance according each photoactivation protocol. These photoactivation methods were evaluated applying photoactivation energies recommended by the resins manufactures. Three brands of resin composites were analysed: Z-250, Charisma and Ultrafill. The cure effectiveness was evaluated through depth of cure experiments. All results were statistically evaluated using one-way and multi-factor analysis of variance (ANOVA). The use of exponential and pulse-delay methods resulted in a significant reduction of the shrinkage stress for all evaluated resins; however, the pulse-delay method required too long a photoactivation time. The increases on the temperature were lower when the exponential photoactivation was applied; however, the temperature variation for all photoactivation protocols was not enough to cause damage in the restoration area. The evaluation of the depth of cure showed that all photoactivation protocols resulted in cured resins with equivalent hardness, indicating that the choice of an alternative photoactivation protocol did not harm the polymerisation. In this way, the results showed the exponential protocol as the best photoactivation technique for practical applications.

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