Sorption and Solubility of Composites Cured with Quartz-tungsten Halogen and Light Emitting Diode Light-curing Units

2008 ◽  
Vol 9 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Luci Regina P. Archegas ◽  
Danilo B. M. Caldas ◽  
Rodrigo N. Rached ◽  
Sergio Vieira ◽  
Evelise M. Souza

Abstract Aim The objective of this study was to evaluate the effect of light polymerization on water sorption and solubility of hybrid composites. Methods and Materials Three composite resins were used to make discs cured with either quartz-tungsten halogen (QTH) or light emitting diode (LED) curing units. The specimens were stored in a desiccator at 37°C and weighted to a constant mass, then immersed in deionized water for different periods of time, and reconditioned until achieving a constant mass. Sorption and solubility were calculated and subjected to analysis of variance (ANOVA) and Tukey tests (p<0.01). Results There were no statistically significant differences between the light sources. Water sorption increased with storage time for all the composites. The lowest sorption was observed for Herculite XRV™, followed by Tetric Ceram™, and Filtek Z250™. Increased storage times reduced the solubility of Filtek Z250™ but did not affect the solubility of Herculite XRV™ and Tetric Ceram™. Conclusion Water sorption and solubility of composites are not affected by the type of polymerization when the same intensity and exposure times are used. Thus, the differences found are probably related to the composition of the materials. Clinical Significance Water sorption and solubility of composites can lead to a shortened service life. However, these properties are not correlated to the type of polymerization. Citation Archegas LRP, Caldas DBM, Rached RN, Vieira S, Souza EM. Sorption and Solubility of Composites Cured with Quartz-tungsten Halogen and Light Emitting Diode Light-curing Units. J Contemp Dent Pract 2008 February;(9)2:073-080.

2013 ◽  
Vol 1 (2) ◽  
pp. 134
Author(s):  
Bruno de Castro Ferreira Barreto ◽  
Anderson Catelan ◽  
Ricardo Coelho Okida ◽  
Gisele Fernanda Gonçalves ◽  
Gisele Rodrigues da Silva ◽  
...  

Clinical performance of composite resins depends largely on their mechanical properties, and those are influenced by several factors, such as the light-curing mode. The purpose of this study was to evaluate the influence of different light sources on degree of conversion (DC), Knoop hardness (KHN) and plasticization (P) of a composite resin. Disc-shaped specimens (5 x 2 mm) of Esthet-X (Dentsply) methacrylate-based microhybrid composite were light-cured using quartz-tungsten-halogen (QTH) Optilight Plus (Gnatus) or light-emitting diode (LED) Ultraled (Dabi Atlante) curing units at 400 and 340 mW/cm2 of irradiance, respectively. After 24 h, absorption spectra of composite were obtained using Nexus 670 (Nicolet) FT-IR spectrometer in order to calculate the DC. The KHN was measured in the HMV-2000 (Shimadzu) microhardness tester under 50 g loads for 15 s, and P was evaluated by percentage reduction of hardness after 24 h of alcohol storage. Data were subjected to t-Student test (alpha = 0.05). QTH device showed lower P and higher KHN than LED (p < 0.05), and no difference between the light-curing units was found for DC (p > 0.05). The halogen-curing unit with higher irradiance promoted higher KHN and lower softening in alcohol than LED.


Author(s):  
Anuradha Vitthal Wankhade ◽  
Sharad Basavraj Kamat ◽  
Santosh Irappa Hugar ◽  
Girish Shankar Nanjannawar ◽  
Sumit Balasaheb Vhate

Introduction: New generation composite resin materials have revolutionized the art of aesthetic dentistry. The clinical success is dependent on effective polymerisation and surface hardness which in turn are dependent on the performance of Light Curing Units (LCU). This study utilises surface hardness as a measure of degree of polymerisation of composite resins achieved by LCUs. Aim: To evaluate the difference in surface hardness of nanohybrid and microhybrid resin composites cured by light curing systems, Light Emitting Diode (LED) and Quartz Tungsten Halogen (QTH). Materials and Methods: In this invitro experimental study, two types of hybrid composites (Nanohybrid and Microhybrid) were tested for surface hardness by using two different light curing systems (LED and QTH). All the Nanohybrid and Microhybrid specimens were cured using LED and QTH LCUs, thus giving four combinations. A total of 60 specimens (6 mm diameter and 2 mm depth) were prepared using Teflon mould with 15 samples for each combination. Surface hardness was measured on upper and lower surface after 24 hours and hardness ratio was calculated. Data was analysed using independent t-test for intergroup comparison. Level of significance was kept at 5%. Results: Surface hardness of resin composites cured by LED LCU was greater than those cured by QTH LCU. Additionally, the hardness value was greater for the upper surface. Nanohybrids showed better surface hardness than Microhybrids for both the LCUs. Conclusion: Nanohybrid composite resins and LED system were found to be more effective in terms of surface hardness as compared to their counterparts.


2006 ◽  
Vol 20 (4) ◽  
pp. 342-346 ◽  
Author(s):  
Daniela Francisca Gigo Cefaly ◽  
Linda Wang ◽  
Liliam Lucia Carrara Paes de Mello ◽  
Janaína Lima dos Santos ◽  
Jean Rodrigo dos Santos ◽  
...  

The Light Emitting Diodes (LED) technology has been used to photoactivate composite resins and there is a great number of published studies in this area. However, there are no studies regarding resin-modified glass-ionomer cements (RMGIC), which also need photoactivation. Therefore, the aim of this study was to evaluate water sorption of two RMGIC photoactivated with LED and to compare this property to that obtained with a halogen light curing unit. A resin composite was used as control. Five specimens of 15.0 mm in diameter x 1.0 mm in height were prepared for each combination of material (Fuji II LC Improved, Vitremer, and Filtek Z250) and curing unit (Radii and Optilight Plus) and transferred to desiccators until a constant mass was obtained. Then the specimens were immersed into deionized water for 7 days, weighed and reconditioned to a constant mass in desiccators. Water sorption was calculated based on weight and volume of specimens. The data were analyzed by two-way ANOVA and Tukey test (p < 0.05). Specimens photocured with LED presented significantly more water sorption than those photocured with halogen light. The RMGIC absorbed statistically significant more water than the resin composite. The type of light curing unit affected water sorption characteristics of the RMGIC.


2010 ◽  
Vol 21 (5) ◽  
pp. 432-438 ◽  
Author(s):  
Francine do Couto Lima Moreira ◽  
Nelson Roberto Antoniosi Filho ◽  
João Batista de Souza ◽  
Lawrence Gonzaga Lopes

The aim of this study was to assess polymerization ability of three light-curing units by evaluating the influence of the light source, curing regimen and permeant (water or ethanol) on sorption, solubility and amount of residual monomers of a dental adhesive. Specimens of Adper Single Bond 2 were fabricated using a stainless steel circular matrix (8 mm x 1 mm). One quartz-tungsten-halogen (QTH) lamp and two light-emitting diode (LED) device at three different curing regimes (L1 = 12 J; L2 = 24 J; L3 = 24 J) were used to cure the specimens. Specimens were stored in two types of permeants - deionized water or 75% ethanol - for two storage times (G1 =7 days; G2 = 30 days). The specimens underwent water sorption and solubility tests, according to ISO 4049:2000 standard. After storage, residual monomers were identified and quantified by high performance liquid chromatography (HPLC). For sorption, L1 showed the highest values and QTH, the lowest. For solubility, in ethanol-stored groups, L1 had also the highest values, and QTH, the lowest, and findings were significantly different from the other curing regimens. L1 leached significantly more monomers than the others, and QTH had the lowest results. In conclusion, the type of light source, the curing regimen and the permeant affected sorption, solubility and amount of residual monomers of the adhesive under study.


2005 ◽  
Vol 16 (3) ◽  
pp. 218-224 ◽  
Author(s):  
Américo Bortolazzo Correr ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Lourenço Correr Sobrinho ◽  
Rubens Nisie Tango ◽  
Luis Felipe Jochims Schneider ◽  
...  

The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and polymerized using different light-curing units and times: conventional QTH (quartz-tungsten-halogen; 700 mW/cm²; 20 s, 30 s and 40 s); LED (light-emitting diode; 440 mW/cm²; 20 s, 30 s and 40 s); PAC (xenon plasma arc; 1700 mW/cm²; 3 s, 4.5 s and 6 s). The specimens were stored at 37°C for 24 h prior to sectioning for Knoop hardness assessment. Three measurements were obtained for each depth: top surface, 1 mm and 2 mm. Data were analyzed statistically by ANOVA and Tukey's test (p<0.05). Regardless of the light source or energy density, Knoop hardness of Z250 was statistically significant higher than that of Esthet-X (p<0.05). Specimens cured with PAC had lower hardness than those cured with QTH and LED (p<0.05). Higher Knoop hardness was obtained when the energy density was increased for LED and PAC (p<0.05). No statistically significant differences (p>0.05) were found for QTH. Knoop hardness values decreased with the increase of depth. The increase of energy density produced composites with higher Knoop hardness means using LED and PAC.


2015 ◽  
Vol 18 (2) ◽  
pp. 65 ◽  
Author(s):  
Dario Raimundo Segreto ◽  
Fabiana Scarparo Naufel ◽  
William Cunha Brandt ◽  
Ricardo Danil Guiraldo ◽  
Lourenço Correr-Sobrinho ◽  
...  

<p><strong>Objective: </strong>The aim of this study was to evaluate the degree of conversion (DC) of seven experimental resin cements formulated with different photoinitiators when activated by two light-curing units (LCUs) through ceramic material. <strong>Material and Methods: </strong>Seven resin blends with different camphorquinone (CQ) and/or phenyl propanedione (PPD) rates were prepared: C5: 0.5% wt CQ; C8: 0.8% wt CQ; P5: 0.5% wt PPD; P8: 0.8% wt PPD; C1P4: 0.1% wt CQ and 0.4% wt PPD; C4P1: 0.4% wt CQ and 0.1% wt PPD; and C4P4: 0.4% wt CQ and 0.4% wt PPD. Each mixture was loaded with 65% wt of silanized filler particles. For photoactivation procedures, two LCUs were used: a quartz-tungsten-halogen (QTH) and a light emitting diode (LED). <strong>Results: </strong>Irradiance (mW/cm²) was calculated by the ratio of the output power by the area of the tip. DC was assessed by Fourier transformed infrared spectroscopy. Data were submitted to a two-way ANOVA and Tukey’s test (5%). DC values do not show significant differences for LCUs regardless of the photoinitiator type. The highest DC was found for experimental cement P8 and the lowest for C5. <strong>Conclusion:</strong> Intermediate DC values were found for the other cements. However, when QTH was used, P8 exhibited differences among C1P4, C4P1 and C5; whereas when LED was employed, P8 differed only for C4P1 and C5. Thus, PPD is a viable alternative for the manufacture of photoactivated cements, and the PPD/CQ association may also be viable since C4P4 was similar to P8.</p>


2021 ◽  
Vol 20 ◽  
pp. e211656
Author(s):  
Gabriela Alves de Cerqueira ◽  
Lais Sampaio Souza ◽  
Rafael Soares Gomes ◽  
Giselle Maria Marchi ◽  
Paula Mathias

Aim: This study evaluated the water sorption and solubility of a light-cured resin cement, under four thicknesses and four opacities of a lithium disilicate ceramic, also considering three light-emitting diode (LED) units. Methods: A total of 288 specimens of a resin cement (AllCem Veneer Trans – FGM) were prepared, 96 samples were light-cured by each of the three light curing units (Valo – Ultradent / Radii-Cal – SDI / Bluephase II – Ivoclar Vivadent), divided into 16 experimental conditions, according to the opacities of the ceramic: High Opacity (HO), Medium Opacity (MO), Low Translucency (LT), High Translucency (HT), and thicknesses (0.3, 0.8, 1.5, and 2.0 mm) (n = 6). The specimens were weighed at three different times: Mass M1 (after making the specimens), M2 (after 7 days of storage in water), and M3 (after dissection cycle), for calculating water sorption and solubility. Results: The higher thickness of the ceramic (2.0 mm) significantly increased the values of water sorption (44.0± 4.0) and solubility (7.8±0.6), compared to lower thicknesses. Also, the ceramic of higher opacity (HO) generated the highest values of sorption and solubility when compared to the other opacities, regardless of the thickness tested (ANOVA-3 factors / Tukey’s test, α = 0.05). There was no influence of light curing units. Conclusion: Higher thicknesses and opacities of the ceramic increased the water sorption and solubility of the tested light-cured resin cement.


2010 ◽  
Vol 04 (01) ◽  
pp. 034-040 ◽  
Author(s):  
Asli Topaloglu Ak ◽  
A. Riza Alpoz ◽  
Oguz Bayraktar ◽  
Fahinur Ertugrul

ABSTRACTObjectives: To measure the release of TEGDMA and BisGMA from two commercially available composite resins; Filtek Z 250 (3M ESPE, Germany), Leaddent (Leaddent, Germany) and two fissure sealants; Helioseal F (3M ESPE, Germany) Enamel Loc (Premiere Rev, USA) over 1, 3 and 7 days after polymerization with standard quartz-tungsten halogen Coltolux II (QHL) (Coltene Switzerland) and a standard blue light emitting diode Elipar Freelight 2 (3M ESPE, Germany).Methods: 9 samples of each material were placed in disc shaped specimens in 1 mm of thickness and 10 mm in diameter (n=36). Each material was polymerized using LED for 20 s (n=12), 40 s (n=12) and halogen for 40 s (n=12), respectively. High Performance Liquid Chromatography (HPLC) was used to measure the amount of monomers released over 1, 3 and 7 days. Data was analyzed using one way ANOVA and Bonferroni test for multiple comparisons with a significance level of .05.Results: LED 20 sec group showed the highest release of monomers at 1, 3 and 7 days in sealant groups. Halogen 40 sec group resulted highest release of monomers for Leaddent at all time intervals (P<.05)Conclusions: Efficiency of the curing unit and applying the recommended curing time of the light activated resin based dental materials is very important to protect the patient from potential hazards of residual monomers. (Eur J Dent 2010;4:34-40)


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