scholarly journals Effect of Two Light-emitting Diode (LED) and One Halogen Curing Light on the Microleakage of Class V Flowable Composite Restorations

2007 ◽  
Vol 8 (2) ◽  
pp. 80-88 ◽  
Author(s):  
Yonca Korkmaz ◽  
Nuray Attar
Keyword(s):  
Light Emitting Diode ◽  
Composite Resins ◽  
Class V ◽  
Polymerization Shrinkage ◽  
Light Emitting ◽  
Flowable Composite ◽  
Composite Restorations ◽  
Curing Methods ◽  
Curing Light

Abstract Aim The disadvantages of light cured composite resin materials with respect to microleakage are predominantly a result of polymerization shrinkage upon curing. It has been shown curing methods play a significant role in polymerization shrinkage of light-cured composite resins. The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with a halogen LCU on microleakage of three different flowable composites using self-etch adhesives. Methods and Materials A total of 63 extracted human premolars were prepared with standardized Class V cavity preparations on the buccal and lingual surfaces of each tooth. The occusal margin of the cavities was located on the enamel and the gingival margin was on dentin. Teeth were randomly assigned to three groups of 21 teeth each as follows: Group 1: Adper Prompt L-Pop + Filtek Flow (3M ESPE); Group 2: AdheSE + Tetric Flow (Ivoclar, Vivadent); and Group 3: Clearfil Protect Bond + Clearfil Protect Liner F (Kuraray Medical Inc.). All the groups were subdivided into three groups according to the curing lights used (n=7). Two LED LCUs, Elipar FreeLight and Elipar FreeLight 2 (3M ESPE), and one halogen-based LCU, Hilux Expert (Benlioglu), were used. All teeth were then immersed in 0.5% basic fuchsin dye solution for 24 hours after thermocycling (500 cycles; between 5°C to 55°C). The teeth then were longitudinally sectioned and observed under a stereomicroscope (40X magnification) by two examiners. The degree of dye penetration was recorded separately for enamel and dentin. Data were analyzed with the Kruskal-Wallis and Mann-Whitney tests with the Bonferroni correction. Results No statistically significant differences in microleakage were observed between groups either on enamel or dentin (p>0.05). Conclusion With the limitation of this in vitro study, the differences in microleakage between LCUs used were not statistically significantly different. Elipar Free Light 2 reduces curing time which can be considered as an advantage. Citation Attar N, Korkmaz Y. Effect of Two Light-emitting Diode (LED) and One Halogen Curing Light on the Microleakage of Class V Flowable Composite Restorations. J Contemp Dent Pract 2007 February;(8)2:080-088.

scholarly journals Effects of Different Light Curing Units/Modes on the Microleakage of Flowable Composite Resins

2008 ◽  
Vol 02 (04) ◽  
pp. 240-246 ◽  
Author(s):  
A. Ruya Yazici ◽  
Cigdem Celik ◽  
Berrin Dayangac ◽  
Gul Ozgunaltay
Keyword(s):  
Light Emitting Diode ◽  
In Vitro Study ◽  
Composite Resins ◽  
Light Emitting ◽  
Flowable Composite ◽  
Group I ◽  
Halogen Light ◽  
Light Curing ◽  
The Difference

Objectives: The aim of this in vitro study was to evaluate the influence of different light curing units and modes on microleakage of flowable composite resins.Methods: Eighty Class V cavities were prepared in buccal and lingual surfaces of 40 extracted human premolars with cervical wall located in dentin and the occlusal wall in enamel. These teeth were randomly assigned into two groups (n=20) and restored with different flowable composites; Group I: Esthet-X Flow, Group II: Grandio Flow. Each group was randomly divided into four subgroups; while the samples of the first subgroup were polymerized with conventional Halogen light, the rest of them were polymerized with different curing modes of Light Emitting Diode (LED). The second subgroup was polymerized with fast-curing; the third subgroup with pulse-curing and those of the fourth subgroup with step-curing modes of LED. After the samples were thermocycled and immersed in dye, they were longitudinally sectioned. Dye penetration was assessed under a stereomicroscope. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests.Results: None of the restorations showed leakage on enamel margins. On dentin margins no significant differences were observed between flowable composite resins polymerized with halogen light (P>.05). While step curing mode of LED presented significant differences between the resins, the difference was insignificant when fast-curing and pulse-curing mode of LED were used. No statistically significant differences were observed between curing units for Esthet-X Flow samples. For Grandio Flow samples, only step-curing mode of LED caused statistically higher leakage scores than halogen and other curing modes of LED (P<.05).Conclusions: The effect of curing units� type and curing mode on flowable composite resin leakage might be material-dependent. (Eur J Dent 2008;2:240-246)

scholarly journals Flexural strength and modulus of elasticity of four dental composites polymerized with light emitting diode (LED) and halogen light

2010 ◽  
Vol 9 (3) ◽  
Author(s):  
Douglas Michielin Sari ◽  
Rita de Cássia Duquia ◽  
Josué Martos ◽  
Prudêncio Willy Rodo Osinaga
Keyword(s):  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Light Emitting Diode ◽  
Testing Machine ◽  
Composite Resins ◽  
Superior Performance ◽  
Dental Composites ◽  
Light Emitting ◽  
Halogen Light ◽  
Curing Light

The purpose of this investigation was to evaluate the flexural strength (FS) and modulus of elasticity (ME) of three microhybrid resins (Filtek Z250; Charisma; P60) and one submicrohybrid resin (Concept) using LED or halogen light polymerization. Twenty specimens (25x2x2 mm) per tested material were prepared and polymerized using a halogen or LED curing unit and stored in distilled water. FS and ME tests were performed on an Instron universal testing machine (0.75mm/min). ANOVA and multiple comparisons (SNK) showed that the two polymerization systems resulted in no significant differences (p>0.05) in the FS of Charisma and Filtek Z250. The two curing systems also produced similar results in the ME of Charisma, Concept and Filtek Z250. Significant differences were found in FS and ME, with the halogen curing light system showing better results than the LED system. The LED LCU systems did not exhibit a superior performance in our investigation of any of the composite resins, in terms of flexural strength and modulus of elasticity.

scholarly journals Color stability of composites subjected to accelerated aging after curing using either a halogen or a light emitting diode source

2007 ◽  
Vol 18 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Fernanda de Carvalho Panzeri Pires-de-Souza ◽  
Lucas da Fonseca Roberti Garcia ◽  
Hisham Mohamad Hamida ◽  
Luciana Assirati Casemiro
Keyword(s):  
Color Change ◽  
Light Emitting Diode ◽  
Accelerated Aging ◽  
Color Stability ◽  
Composite Resins ◽  
Significance Level ◽  
Light Emitting ◽  
Before And After ◽  
Qth Light

The purpose of this study was to evaluate, in vitro, the color stability of three composite resins of two different shades (A3 and C3) cured with either a quartz tungsten halogen (QTH) or a light emitting diode (LED) source. Forty specimens (20 x 2 mm) were prepared for each composite (Tetric Ceram®, Heliomolar® and Esthet-X®), being 20 for each shade. In each group, 10 specimens were light-cured using the QTH unit and 10 with the LED source. The shade of the materials was evaluated before and after submitting the specimens to artificial accelerated aging (4 h UV-B/4 h condensing vapor), using a reflection spectrophotometer. deltaE means were calculated and analyzed statistically by 2-way ANOVA and Tukey's test at 5% significance level. Both A3 and C3 shades of Esthet-X composite resin showed the lowest color change when cured with the QTH light, while Tetric C3 cured with the QTH light showed the highest color change.

scholarly journals Polymerization shrinkage stress of composites photoactivated by different light sources

2009 ◽  
Vol 20 (4) ◽  
pp. 319-324 ◽  
Author(s):  
Fernanda de Carvalho Panzeri Pires de Souza ◽  
Brahim Drubi Filho ◽  
Luciana Assirati Casemiro ◽  
Lucas da Fonseca Roberti Garcia ◽  
Simonides Consani
Keyword(s):  
Light Emitting Diode ◽  
Testing Machine ◽  
Adhesive System ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Light Sources ◽  
Polymerization Shrinkage ◽  
Light Emitting ◽  
Halogen Light ◽  
Glass Rods

The purpose of this study was to compare the polymerization shrinkage stress of composite resins (microfilled, microhybrid and hybrid) photoactivated by quartz-tungsten halogen light (QTH) and light-emitting diode (LED). Glass rods (5.0 mm x 5.0 cm) were fabricated and had one of the surfaces air-abraded with aluminum oxide and coated with a layer of an adhesive system, which was photoactivated with the QTH unit. The glass rods were vertically assembled, in pairs, to a universal testing machine and the composites were applied to the lower rod. The upper rod was placed closer, at 2 mm, and an extensometer was attached to the rods. The 20 composites were polymerized by either QTH (n=10) or LED (n=10) curing units. Polymerization was carried out using 2 devices positioned in opposite sides, which were simultaneously activated for 40 s. Shrinkage stress was analyzed twice: shortly after polymerization (t40s) and 10 min later (t10min). Data were analyzed statistically by 2-way ANOVA and Tukey's test (a=5%). The shrinkage stress for all composites was higher at t10min than at t40s, regardless of the activation source. Microfilled composite resins showed lower shrinkage stress values compared to the other composite resins. For the hybrid and microhybrid composite resins, the light source had no influence on the shrinkage stress, except for microfilled composite at t10min. It may be concluded that the composition of composite resins is the factor with the strongest influence on shrinkage stress.

scholarly journals In Vitro Comparative Evaluation of Microleakage of Newly Introduced Dyad Flow and Total and Self Etch Adhesives in Class V Resin Composite Restorations

2016 ◽  
Vol 63 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Navjot S. Mann ◽  
Sameer Makkar ◽  
Reetika Sharma
Keyword(s):  
Resin Composite ◽  
Adhesive System ◽  
Ordinal Scale ◽  
Human Teeth ◽  
Class V ◽  
Flowable Composite ◽  
Composite Restorations ◽  
Group I ◽  
Self Etch

SUMMARY Introduction The aim of this study was to evaluate marginal sealing ability of newly introduced Dyad Flow flowable composite and compare to total-etch and self-etch adhesive system at the coronal and apical margins of class V resin composite restorations. Material and Methods A standard class V cavity (3 mm mesiodistal width, 3 mm occlusogingival height and 1.5 mm axial depth) was prepared on the buccal surface of freshly extracted sound human teeth. Occlusal and gingival margins of the cavities were located in enamel and cementum/dentin, respectively. Teeth were randomly assigned into the three groups (n=10) and restored with different composite materials following the manufacturer’s instructions: group I was restored with nanohybrid resin composite using total-etch bonding agent; group II was restored with nanohybrid resin composite using self-etch technique; group III was restored with flowable composite (Dyad Flow), respectively. After finishing and polishing, the teeth were coated with nail varnish and immersed in rhodamine B dye and sectioned longitudinally. Dye penetration was examined under stereomicroscope and scored separately for occlusal and gingival margins on a 0–3 ordinal scale. Data were analyzed with Kruskal–Wallis, Mann–Whitney and Wilcoxon tests (a=0.05). Result Statistical analysis showed that specimens restored with the total-etch and self-etch adhesive systems revealed reduced leakage at the coronal margin. At the apical margin, Dyad Flow showed greater leakage than other groups. Conclusion Newly introduced flowable composite Dyad Flow showed inferior adhesive bond with enamel and dentin compared to total-etch and self-etch techniques.

scholarly journals The Effect of Irradiance on the Degree of Conversion and Volumetric Polymerization Shrinkage of Different Bulk-Fill Resin-Based Composites: An In Vitro Study

2020 ◽  
Author(s):  
Abrar N. Bin Nooh ◽  
Hend Al Nahedh ◽  
Mohammad AlRefeai ◽  
Fahad Alkhudhairy
Keyword(s):  
High Intensity ◽  
Statistical Difference ◽  
Light Emitting Diode ◽  
In Vitro Study ◽  
Degree Of Conversion ◽  
Polymerization Shrinkage ◽  
Low Intensity ◽  
Light Intensities ◽  
Curing Light

Abstract Objective The influence of different light-emitting diode (LED) curing light intensities on the degree of conversion (DC) and volumetric polymerization shrinkage (VPS) of bulk-fill resin-based composite (RBC) restorative materials was evaluated. Materials and Methods Twenty-four specimens of each RBC material (Filtek one bulk-fill posterior, Reveal HD Bulk, Tetric N-Ceram, and Filtek Z350) were prepared. The RBCs were shaped in molds and cured using an LED curing light unit at high-intensity (1,200 mW/cm2) for 20 seconds and low-intensity (650 mW/cm2) for 40 seconds Fourier-transform infrared (FTIR) spectroscopy was used to determine the DC and microcomputed tomography was used to evaluate VPS. Data were analyzed using one- and two-way ANOVA, independent t-test, and Tukey’s and Scheffe’s post hoc multiple comparison tests. Results With high-intensity curing light, Reveal HD showed the highest DC (85.689 ± 6.811%) and Tetric N-Ceram the lowest (52.60 ± 9.38%). There was no statistical difference in VPS when using high- or low-intensity curing light. The highest VPS was observed for Reveal HD (2.834–3.193%); there was no statistical difference (p > 0.05) among the other RBCs. Conclusion Curing light intensities do not significantly influence the VPS of RBC materials. Reveal HD bulk cured with high-intensity light had the highest DC.

scholarly journals In Vitro Biocompatibility of Contemporary Bulk-fill Composites

2015 ◽  
Vol 40 (6) ◽  
pp. 644-652 ◽  
Author(s):  
WS Toh ◽  
AUJ Yap ◽  
SY Lim
Keyword(s):  
Cell Viability ◽  
Light Emitting Diode ◽  
Specimen Thickness ◽  
Cytotoxic Effects ◽  
Light Emitting ◽  
In Vitro Biocompatibility ◽  
Contrast Microscopy ◽  
Curing Light ◽  
L929 Mouse

SUMMARY This study evaluated the biocompatibility of contemporary bulk-fill resin-based composites (RBCs) including PRG (pre-reacted glass ionomer) materials based on the International Organization for Standardization 10993. In addition, the effect of composite thickness on cytotoxicity was also assessed. Two standard composites, two bulk-fill PRG RBCs, and three bulk-fill non-PRG RBCs were investigated. Block-shaped specimens of 2-mm and 4-mm thickness were cured with an irradiance of 700 mW/cm2 for 20 seconds with a light-emitting diode curing light and eluted with culture medium at 37°C for 24 hours. L929 mouse fibroblasts were exposed to extracts at varying dilutions (1:1, 1:2, and 1:10) for 24 hours. Analyses were performed to assess cytotoxicity, phase contrast microscopy, and quantitative cell viability. Among the bulk-fill RBCs, extracts of PRG materials resulted in the lowest cell viability. At 4-mm thickness, undiluted extracts of bulk-fill non-PRG RBCs had significantly higher cell viability than the standard composites. Chemical composition, specimen thickness, and testing concentrations of extracts had significant effects on cell viability and morphology. Cytotoxic effects of composites on cell viability were parallel with cell morphologic changes. Not all bulk-fill RBCs demonstrated high cell viability (&gt;70%) at 4-mm thickness despite manufacturers' recommendations of bulk placement and curing.

Degree of Conversion and Polymerization Shrinkage of Bulk-Fill Resin-Based Composites

2017 ◽  
Vol 42 (1) ◽  
pp. 82-89 ◽  
Author(s):  
P Yu ◽  
AUJ Yap ◽  
XY Wang
Keyword(s):  
Light Emitting Diode ◽  
Degree Of Conversion ◽  
Attenuated Total Reflectance ◽  
Polymerization Shrinkage ◽  
Light Emitting ◽  
Significant Difference ◽  
Before And After ◽  
Light Curing ◽  
Curing Light ◽  
The Mean

SUMMARY This study evaluated the degree of conversion (DC) and polymerization shrinkage (PS) of contemporary bulk-fill resin-based composites (RBCs) including giomer materials. Two giomer bulk-fill (Beautifil Bulk Restorative [BBR], Beautifil Bulk Flowable [BBF]), two nongiomer bulk-fill (Tetric N-Ceram Bulk-fill [TNB], Smart Dentin Replacement [SDR]), and three conventional non–bulk-fill (Beautifil II [BT], Beautifil Flow Plus [BF], Tetric N-Ceram [TN]) RBCs were selected for the study. To evaluate the DC, disc-shaped specimens of 5-mm diameter and 2-mm, 4-mm, and 6-mm thickness were fabricated using customized Teflon molds. The molds were bulk filled with the various RBCs and cured for 20 seconds using a light-emitting diode curing light with an irradiance of 950 mW/cm2. The DC (n=3) was determined by attenuated total reflectance Fourier transform infrared spectroscopy by computing the spectra of cured and uncured specimens. PS (n=3) was measured with the Acuvol volumetric shrinkage analyzer by calculating specimen volumes before and after light curing. The mean DC for the various materials ranged from 46.03% to 69.86%, 45.94% to 69.38%, and 30.65% to 67.85% for 2 mm, 4 mm, and 6 mm, respectively. For all depths, SDR had the highest DC. While no significant difference in DC was observed between depths of 2 mm and 4 mm for the bulk-fill RBCs, DC at 2 mm was significantly greater than 6 mm. For the conventional RBCs, DC at 2 mm was significantly higher than at 4 mm and 6 mm. Mean PS ranged from 1.48% to 4.26% for BBR and BF, respectively. The DC at 2 mm and PS of bulk-fill RBCs were lower than their conventional counterparts. At 4 mm, the DC of giomer bulk-fill RBCs was lower than that of nongiomer bulk-fill materials.

scholarly journals In Vitro Effect of Photodynamic Therapy with Different Lights and Combined or Uncombined with Chlorhexidine on Candida spp.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta
Keyword(s):  
Photodynamic Therapy ◽  
Light Emitting Diode ◽  
Antimicrobial Effect ◽  
Photodynamic Treatment ◽  
Candida Spp ◽  
Promising Alternative ◽  
Light Emitting ◽  
Colony Forming Units ◽  
Vitro Effect

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.

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