Study Regarding the Influence of Polymerization Mode of Light Unit on Surface Microhardness of Composite Resins

2015 ◽  
Vol 754-755 ◽  
pp. 271-275
Author(s):  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Manuela Cristina Perju ◽  
Andrei Victor Sandu ◽  
Sorin Andrian
Keyword(s):  
Vickers Hardness ◽  
High Intensity ◽  
Composite Resin ◽  
Surface Hardness ◽  
Pulse Mode ◽  
Composite Resins ◽  
Surface Microhardness ◽  
Mean Values ◽  
Inner Diameter ◽  
Composite Samples

The aim of the study was to compare the surface microhardness of composite resins polymerized in different mode of light unit. Three commercial composite resins: Charisma (Heraeus Kulzer Co.), Filtek Z 250 (3M ESPE Co.) and G-aenial Anterior (GC Company Co.), were used in this study. Fifteen samples of each material were obtained by placing the composite resin in plastic rings having 2 mm high and 6 mm inner diameter. All composite samples were cured using blue light-emitted diode G 0010 (SKI, China). Five samples were cured using ramp mode of the light unit, five samples were cured using single light: high intensity (constant) mode and five samples were cured using pulse mode. The samples were finished and polished and then stored in distilled water, at room temperature for 48 hours. The samples were subjected to microhardness evaluation using microhardness tester (Micro-Vickers Hardness System CV-400DMTM, CV Instruments Namicon). A 50 g load was applied through a Vickers indenter. For each sample three indentations were made in different areas of the sample and the value of Vickers hardness was calculated as a mean result of the three recordings. Statistical Mann-Whitney U test and Kruskal-Wallis test were used to compare the values of surface hardness. Polymerization of all three composite resins using pulse mode leaded to significantly lowest mean hardness values and single light high intensity mode to the highest values. Filtek Z250 composite resin showed the highest microhardness mean values in all three polymerization mode and Charisma the lowest values. Surface microhardness of composite resins is influenced by different modes of light unit. Single light high intensity mode of polymerization leaded to the highest values of microhardness, followed in descending order by ramp and pulse mode. The best results regarding the surface microhardness was recorded for Filtek Z250composite resin, followed in descending order by G-aenial Anterior and Charisma.

scholarly journals Evaluation of the surface hardness of composite resins before and after polishing at different times

2006 ◽  
Vol 14 (3) ◽  
pp. 188-192 ◽  
Author(s):  
Michelle Alexandra Chinelatti ◽  
Daniela Thomazatti Chimello ◽  
Renata Pereira Ramos ◽  
Regina Guenka Palma-Dibb
Keyword(s):  
Statistical Analysis ◽  
Vickers Hardness ◽  
Composite Resin ◽  
Surface Hardness ◽  
Composite Resins ◽  
The Other ◽  
Test Results ◽  
Tukey Test ◽  
Natural Flow ◽  
Before And After

PURPOSE: The aim of this study was to evaluate the surface hardness of six composite resins: Revolution, Natural Flow, Fill Magic Flow, Flow-it! (flowables), Silux Plus (microfilled) and Z100 (minifilled) before and after polishing at different times. MATERIALS AND METHODS: For this purpose, 240 specimens (5mm diameter, 1.4mm high) were prepared. Vickers hardness was determined before and after polishing at different times: immediately, 24h, 7 and 21 days after preparation of the samples. Statistical analysis was performed by ANOVA and Tukey test. RESULTS: There was no difference in the hardness of flowable resins, which had lower hardness than the minifilled resin. The minifilled resin showed the highest surface hardness as compared to the other materials (p<0.01). All materials exhibited higher hardness after polishing, being more evident after 7 days. CONCLUSION: It may be concluded that, regardless of the composite resin, surface hardness was considerably increased when polishing was delayed and performed 1 week after preparation of the samples.

Effect of layer thickness on residual monomer release in polymerization of bulk-fill composites

2021 ◽  
pp. 096739112199958
Author(s):  
Vahti Kılıç ◽  
Feridun Hurmuzlu ◽  
Yılmaz Ugur ◽  
Suzan Cangul
Keyword(s):  
Stainless Steel ◽  
Layer Thickness ◽  
Composite Resin ◽  
Ethanol Solution ◽  
Composite Resins ◽  
Residual Monomer ◽  
Steel Mold ◽  
Nanohybrid Composite ◽  
Composite Samples

The aim of the present study was to investigate and compare the quantity of residual monomers leached from the bulk-fill composites with different compositions polymerized at varying layer thickness. Three bulk-fill (X-tra-fil, Beautifil Bulk Restorative, Fill-Up) and a nanohybrid composite (Filtek Z550) were used for the study. The composite resin samples were prepared with a stainless steel mold. For each composite, two groups were constructed. The samples in the first group were prepared using the 2 + 2 mm layering technique. In the second group, the composite samples were applied as a 4 mm-thick one layer and polymerized. Then, each composite samples were kept in a 75% ethanol solution and residual monomers released from composite resins were analyzed with an HPLC device after 24hour and 1 month. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Except the Fill-Up, all of residual monomer elution from the bulk-fill composites was significantly affected by the layer thickness (p < 0.05). The greatest monomer release was detected at 1 month after polymerization as a single 4 mm layer for Beautifil Bulk Restorative. Fill-Up composite showed similar residual monomer release in polymerization at different layer thicknesses compared to other composite resins. In the 2 + 2 mm layering technique, the least monomer elution was detected in the Filtek Z550 composite group. While Bis-GMA was the most released monomer in X-tra fil composite, UDMA was the most released monomer in all other composite resins. During polymerization of the bulk-fill composite, the layer thickness of the composite applied may affect the amount of residual monomers released from the composite resins. Conventional composites may release less monomer than bulk-fill composites when used with layering.

Physical Property Evaluation of Four Composite Materials

2013 ◽  
Vol 38 (5) ◽  
pp. E144-E153 ◽  
Author(s):  
M Chang ◽  
J Dennison ◽  
P Yaman
Keyword(s):  
Flexural Strength ◽  
Physical Properties ◽  
Vickers Hardness ◽  
Dwell Time ◽  
Testing Machine ◽  
Surface Hardness ◽  
Composite Resins ◽  
Bending Test ◽  
Polymerization Shrinkage ◽  
Hardness Tests

SUMMARY Purpose The purpose of this study was to evaluate the physical properties of current formulations of composite resins for polymerization shrinkage, surface hardness, and flexural strength. In addition, a comparison of Knoop and Vickers hardness tests was made to determine if there was a correlation in the precision between the two tests. Materials and Methods Four composite resin materials were used: Filtek LS (3M-ESPE), Aelite LS (Bisco), Kalore (GC America), and Empress Direct (Ivoclar). Ten samples of each composite (shade Vita A2) were used. Polymerization shrinkage was measured with the Kaman linometer using 2-mm-thick samples, cured for 40 seconds and measured with digital calipers for sample thickness. Surface microhardness samples were prepared (2-mm thick × 12-mm diameter) and sequentially polished using 600-grit silicone carbide paper, 9 μm and 1 μm diamond polishing solutions. After 24 hours of dry storage, Knoop (200 g load, 15 seconds dwell time) and Vickers (500 g load, 15 seconds dwell time) hardness tests were conducted. Flexural strength test samples (25 × 2 × 2 mm) were stored in 100% relative humidity and analyzed using a three-point bending test with an Instron Universal Testing Machine (Instron 5565, Instron Corp) applied at a crosshead speed of 0.75 ± 0.25 mm/min. Maximum load at fracture was recorded. One-way analysis of variance and Tukey multiple comparison tests were used to determine significant differences in physical properties among materials. Results Filtek LS had significantly lower shrinkage (0.45 [0.39] vol%). Aelite LS demonstrated the greatest Knoop surface hardness (114.55 [8.67] KHN), followed by Filtek LS, Kalore, and Empress Direct (36.59 [1.75] KHN). Vickers surface hardness was significantly greater for Aelite LS (126.88 [6.58] VH), followed by Filtek LS, Kalore, and Empress Direct (44.14 [1.02] VH). Flexural strength (MPa) was significantly higher for Aelite LS and Filtek LS (135.75 [17.35]; 129.42 [9.48]) than for Kalore and Empress Direct (86.84 [9.04]; 92.96 [9.27]). There is a strong correlation between results obtained using Knoop and Vickers hardness tests (r=0.99), although Vickers values were significantly greater for each material. Conclusion Results suggest that Aelite LS possesses superior hardness and flexural strength, while Filtek LS has significantly less shrinkage compared with the other composites tested.

scholarly journals THE EFFECT OF Musa acuminata AND Ocimum basilicum MIXED EXTRACTS TO THE SURFACE HARDNESS OF BIOACTIVE COMPOSITE RESIN

2020 ◽  
Vol 5 (2) ◽  
pp. 172
Author(s):  
Dewi Puspitasari ◽  
Maharani Laillyza Apriasari ◽  
Dewi Rahayu ◽  
Priyawan Rachmadi
Keyword(s):  
Mechanical Properties ◽  
Composite Resin ◽  
Surface Hardness ◽  
Ocimum Basilicum ◽  
Musa Acuminata ◽  
Dental Restoration ◽  
Composite Resins ◽  
Mixed Solution ◽  
Leaf Extracts ◽  
Banana Stem

ABSTRACTBackgrounds: The use of mouthwash daily may influence the mechanical properties of bioactive composite resin as a dental restoration, one of the mechanical properties is surface hardness. Herbal mouthwash can be used to minimize the side effect of mouthwash that contain alcohol. Mauli banana stem and basil leaf extracts can be produced into herbal mouthwash. Methods: Thirty specimens (10mm diameter x 2mm thick; n=5/group) bioactive composite resins were immersed in a mixed solution of Mauli banana and basil leaf extracts with concentration of 25%, 50%, 75 %%, 100%, the control group of chlorhexidine gluconate 0.2% and aquadest for 7 days in 37oC. Measurement of the surface hardness was using the Vickers Microhardness Tester with 100 gf load for 15 seconds. Results: One Way ANOVA and Post Hoc Bonferroni exhibited the significant differences (p <0.05) in hardness values between the specimens that immersed in the mixed solution Mauli banana and Basil leaf extracts, which in the concentration of 100% (4,49 ± 4,61 VHN) compared with 25% (38,20 ± 2,58 VHN), 50% (41,40 ± 3,84 VHN) and 75% concentration (40,40 ± 3,55 VHN). There was no siginificant difference (p >0.05) between specimens immersed in CHX, aquadest and the mixed solution of mauli banana and basil leaf extracts in all concentration. Conclusion: There is no change in bioactive composite resin surface hardness after immersed in the mixed solution of Mauli Banana stem (Musa acuminata) and Basil leaf (Ocimum basilicum) extracts.Keywords: Basil leaf extract, Bioactive resin, Mauli Banana stem extract, Surface hardness

scholarly journals Comparative study of surface microhardness of methacrylate-based composite resins polymerized with light-emitting diodes and halogen

2013 ◽  
Vol 07 (03) ◽  
pp. 327-335 ◽  
Author(s):  
Camila Sabatini
Keyword(s):  
Light Emitting Diodes ◽  
Filler Particle ◽  
Surface Hardness ◽  
Composite Resins ◽  
Test Results ◽  
Surface Microhardness ◽  
Light Emitting ◽  
Hardness Tester ◽  
Quartz Tungsten Halogen ◽  
Light Curing

ABSTRACT Objective: The aim of this study was to evaluate the effect of polymerization with quartz-tungsten-halogen (QTH) and light-emitting diodes (LED) on the surface microhardness of eight commercially available light-polymerized, methacrylate-based composite resins, with different filler particle composition (microfill, minifill, nanohybrids, and microhybrids) immediately after polymerization, after 24 hours, and after three months of storage. Materials and Methods: Eighty disk-shaped specimens were prepared using a split Teflon mold (6 × 2 mm) and were irradiated with either the QTH (Elipar 2500; 600 mW/cm 2 ) for 20 seconds or an LED (Bluephase G2; 1,200 mW/cm 2 ) for 40 seconds. The microhardness values were recorded using a Vickers hardness tester at a 300 g load for 15 seconds, immediately after polymerization, after 24 hours, and after three months of dark aging in distilled water at 37°C. Statistical analysis was performed using a two-way analysis of variance (ANOVA) and the Tukey′s test. Results: The baseline values demonstrated a significant effect of the composite and the interaction composite-LCU on the microhardness (P < 0.05). At 24 hours, only the composite variable showed a significant effect on the hardness values (P < 0.05). After three months, the composite, LCU, and the interaction composite-LCU all demonstrated a significant effect on the microhardness (P < 0.05). Conclusions: The effectiveness of polymerization, measured in terms of surface hardness, was shown to be dependent not only on the type of light curing unit, but also on the type of composite. Moreover, the choice of composite was shown to affect the performance of the light curing unit.

Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin

2007 ◽  
Vol 8 (6) ◽  
pp. 1-8 ◽  
Author(s):  
José Roberto Lovadino ◽  
Gláucia Maria Bovi Ambrosano ◽  
Flávio Henrique Baggio Aguiar ◽  
Aline Braceiro ◽  
Débora Alves Nunes Leite Lima
Keyword(s):  
Hybrid Composite ◽  
High Intensity ◽  
Composite Resin ◽  
Resin Composite ◽  
Composite Resins ◽  
Bottom Surface ◽  
Curing Time ◽  
Experimental Conditions ◽  
Light Curing ◽  
Effect Of Light

Abstract Aims The aim of this in vitro study was to evaluate the influence of light curing modes and curing time on the microhardness of a hybrid composite resin. Methods and Materials Forty-five Z250 composite resin specimens (3M-ESPE Dental Products, St. Paul, MN, USA) were randomly divided into nine groups (n=5): three polymerization modes (conventional - 550 mW/ cm2; light-emitting diodes (LED) - 360mW/cm2, and high intensity - 1160 mW/cm2) and three light curing times (once, twice, and three times the manufacturer's recommendations). All samples were polymerized with the light tip 8 mm from the specimen. Knoop microhardness measurements were obtained on the top and bottom surfaces of the sample. Results Conventional and LED polymerization modes resulted in higher hardness means and were statistically different from the high intensity mode in almost all experimental conditions. Tripling manufacturers’ recommended light curing times resulted in higher hardness means; this was statistically different from the other times for all polymerization modes in the bottom surface of specimens. This was also true of the top surface of specimens cured using the high intensity mode but not of conventional and LED modes using any of the chosen curing times. Top surfaces showed higher hardness than bottom surfaces. Conclusions It is important to increase the light curing time and use appropriate light curing devices to polymerize resin composite in deep cavities to maximize the hardness of hybrid composite resins. Citation Aguiar FHB, Braceiro A, Lima DANL, Ambrosano GMB, Lovadino JR. Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin. J Contemp Dent Pract 2007 September; (8)6:001-008.

scholarly journals Food Simulating Organic Solvents for Evaluating Crosslink Density of Bulk Fill Composite Resin

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Neveen M. Ayad ◽  
Hala A. Bahgat ◽  
Eman Hussain Al Kaba ◽  
Maryam Hussain Buholayka
Keyword(s):  
Organic Solvent ◽  
Methyl Ethyl Ketone ◽  
Organic Solvents ◽  
Vickers Hardness ◽  
Crosslink Density ◽  
Composite Resin ◽  
Composite Resins ◽  
Methyl Ethyl ◽  
The Difference ◽  
Crosslink Densities

Objectives.To evaluate crosslink densities of two bulk fill composite resins and determine if the used Food Simulating Organic Solvent (FSOS) affected them.Methods.Forty specimens were prepared from SureFill and SonicFill bulk fill composite resins, 20 each. All specimens were stored dry for 24 h. Each group was divided into 2 subgroups: stored in ethanol (E) 75% or in methyl ethyl ketone (MEK) 100% for 24 h. Crosslink density was evaluated by calculating the difference between the Vickers hardness numbers of the specimens stored dry and after their storage in FSOS. The data were statistically analyzed usingt-test.Results.The means of crosslink density in E and MEK were 6.99% and 9.44% for SureFill and 10.54% and 11.92% for SonicFill, respectively.t-test displayed significant differences between crosslink densities of SureFill and SonicFill: (P<0.0001) in E and (P=0.02) in MEK and between crosslink densities of SureFill in E and MEK (P=0.02).Conclusions.Crosslink density of bulk fill composite resin can be evaluated using E or MEK. SureFill has higher crosslink density than SonicFill in both E and MEK.

scholarly journals Comparison of time-dependent changes in the surface hardness of different composite resins

2013 ◽  
Vol 07 (S 01) ◽  
pp. S020-S025 ◽  
Author(s):  
Suat Ozcan ◽  
Ihsan Yikilgan ◽  
Mine Betul Uctasli ◽  
Oya Bala ◽  
Zeliha Gonca Bek Kurklu
Keyword(s):  
Composite Resin ◽  
Surface Hardness ◽  
Multiple Comparisons ◽  
Composite Resins ◽  
Time Dependent ◽  
Bottom Surface ◽  
Significance Level ◽  
Hardness Tester ◽  
Significant Difference ◽  
Hardness Values

ABSTRACT Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker′s hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey′s test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (p < 0.05). The lowest was obtained with Filtek Silorane. The hardness values of all test groups increased after 24 h (p < 0.05). Conclusions: Although silorane-based composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites.

scholarly journals Impact of Fast High-Intensity versus Conventional Light-Curing Protocol on Selected Properties of Dental Composites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1381
Author(s):  
Sufyan Garoushi ◽  
Lippo Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
High Intensity ◽  
Composite Resin ◽  
Light Transmission ◽  
Wear Test ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Ftir Spectrometry ◽  
Double Bond Conversion ◽  
Light Curing ◽  
Chewing Simulator

To study the influence of fast high-intensity (3-s) and conventional (20-s) light curing protocols on certain physical properties including light-transmission and surface wear of two nano-hybrid composite resins (Tetric PowerFill and Essentia U) specifically designed for both curing protocols. According to ISO standards, the following properties were investigated: flexural properties, fracture toughness and water sorption/solubility. FTIR-spectrometry was used to calculate the double bond conversion (DC%). A wear test using a chewing simulator was performed with 15,000 chewing cycles. A tensilometer was used to measure the shrinkage stress. Light transmission through various thicknesses (1, 2, 3 and 4 mm) of composite resins was quantified. The Vickers indenter was utilized for evaluating surface microhardness (VH) at the top and the bottom sides. Scanning electron microscopy was utilized to investigate the microstructure of each composite resin. The light curing protocol did not show a significant (p > 0.05) effect on the mechanical properties of tested composite resins and differences were material-dependent. Shrinkage stress, DC% and VH of both composite resins significantly increased with the conventional 20 s light curing protocol (p < 0.05). Light curing conventional composite resin with the fast high-intensity (3-s) curing protocol resulted in inferior results for some important material properties.

scholarly journals Influence of Using Different Light Curing Devices on the Microhardness of a Bulk-Fill Resin

2021 ◽  
Vol 22 (3) ◽  
pp. 234-237
Author(s):  
João Marcos Carvalho Silva ◽  
Alina Barreto de Negreiros Ribeiro Silva ◽  
Ayrton de Sá Brandim ◽  
Mila Oliveira Santos Viana
Keyword(s):  
High Power ◽  
Composite Resin ◽  
Physical And Mechanical Properties ◽  
Composite Resins ◽  
Surface Microhardness ◽  
Hardness Tests ◽  
Light Curing ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

AbstractBulk Fill resins are a class of resin composites widely used today and have low polymerization shrinkage. However, these materials need an appropriate light curing technique to have good physical and mechanical properties. The objective of this study was to evaluate the surface microhardness of Bulk Fill resins after their light-curing with two types of high- power light-curing devices, using three techniques. 30 specimens were made with a nanoparticulate composite resin Opus Bulk Fill (FGM) and were divided into three groups according to the device and intensity of light curing: Group 1 - light curing with the Emitter B device (Schuster); Group 2 - light curing with the Valo device (Ultradent) at Standard power; and Group 3 - light curing with the Valo device at high power. Higher values of top surface microhardness were observed in Group 3 (microhardness = 53.6 μm), followed by Group 2 (microhardness = 52.1 μm) and Group 1 (microhardness = 33.1 μm), with p values <0.05. Therefore, the Valo light curing unit, in the two powers used, provided greater surface microhardness for the studied specimens.Keywords: Polymerization. Composite Resins. Hardness Tests. Dentistry.ResumoResinas Bulk Fill são uma classe de compósitos resinosos bastante utilizados atualmente e apresentam baixa contração de polimerização. Entretanto, esses materiais necessitam de uma adequada técnica de fotopolimerização para que apresentem boas propriedades físicas e mecânicas. O objetivo deste estudo foi avaliar a microdureza superficial de resinas Bulk Fill fotopolimerizadas com dois tipos de aparelhos fotopolimerizadores de alta potência, em três técnicas de utilização. Foram confeccionados 30 corpos de prova com uma resina composta nanoparticulada Opus Bulk Fill (FGM) e divididos em três grupos de acordo com o aparelho e intensidade de fotopolimerização: Grupo 1 – fotopolimerização com o aparelho Emitter B. (Schuster), Grupo 2 – fotopolimerização com o aparelho Valo (Ultradent) na potência Standard, Grupo 3 – fotopolimerização com o aparelho Valo em alta potência, posteriormente foi realizado o teste de microdureza de Vickers na região superficial de topo dos corpos de prova. Observou-se maiores valores de microdureza superficial de topo no Grupo 3 (microdureza= 53,6 μm), seguido pelo Grupo 2 (microdureza= 52,1 μm) e Grupo 1 (microdureza= 33,1 μm), com valores de p<0,05. Assim sendo, o aparelho fotopolimerizador Valo, nas duas potências utilizadas, forneceu maior microdureza superficial para os corpos de prova estudados.Palavras-chave: Polimerização. Resinas Compostas. Testes de Dureza. Odontologia.

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