Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units

2017 ◽  
Vol 42 (5) ◽  
pp. 497-504 ◽  
Author(s):  
A Tongtaksin ◽  
C Leevailoj
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Bottom Surface ◽  
Light Emitting ◽  
Led Light ◽  
Battery Charge ◽  
Light Intensities ◽  
Light Curing ◽  
The Stability

SUMMARY This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units—1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED—were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm2. The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm2. In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm2. There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was discharged, with a coincident reduction in the units' ability to polymerize resin composite. Therefore, the intensity of an LED light-curing unit should be evaluated during the life of its battery charge to ensure that sufficient light intensity is being generated.

scholarly journals Microhardness of resin-based materials polymerized with LED and halogen curing units

2005 ◽  
Vol 16 (2) ◽  
pp. 98-102 ◽  
Author(s):  
Daniela Francisca Gigo Cefaly ◽  
Giovano Augusto de Oliveira Ferrarezi ◽  
Celiane Mary Carneiro Tapety ◽  
José Roberto Pereira Lauris ◽  
Maria Fidela de Lima Navarro
Keyword(s):  
Statistical Analysis ◽  
Light Emitting Diode ◽  
Surface Hardness ◽  
Bottom Surface ◽  
Halogen Lamp ◽  
Light Emitting ◽  
Led Light ◽  
Significant Difference ◽  
Light Curing ◽  
Curing Light

The purpose of this study was to evaluate the microhardness of resin-based materials polymerized with a LED (light-emitting diode) light-curing unit (LCU) and a halogen LCU. Twenty cylindrical specimens (3.0 mm in diameter and 2.0 mm high) were prepared for each tested material (Z100, Definite and Dyract). Specimens were light-cured with two LCUs (Ultraled and Curing Light 2500) for either 40 or 60 s on their top surfaces. Hardness was measured on top and bottom surfaces of each specimen. Statistical analysis was done by ANOVA and Tukey's test (p<0.05). There was no significant difference in hardness between LED LCU and halogen LCU for Z100 and Dyract on top surface. Conversely, lower hardness was recorded when Definite was light-cured with the LED LCU than with the halogen lamp. On bottom surface, hardness was significantly lower for all materials light-cured with LED LCU. Z100 was harder than Dyract and Definite regardless of the light curing unit. There was no significant difference in hardness between the exposure times on top surface. Higher hardness was obtained when the materials were light-cured for 60 s on bottom surface. The tested LED was not able to produce the same microhardness of resin-based materials as the halogen LCU.

scholarly journals Design of a Secondary Freeform Lens of UV LED Mosquito-Trapping Lamp for Enhancing Trapping Efficiency

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 335 ◽  
Author(s):  
Wei-Hsiung Tseng ◽  
Diana Juan ◽  
Wei-Cheng Hsiao ◽  
Cheng-Han Chan ◽  
Hsin-Yi Ma ◽  
...  
Keyword(s):  
Light Intensity ◽  
Intensity Distribution ◽  
Light Emitting Diode ◽  
Trapping Efficiency ◽  
Axially Symmetric ◽  
Light Intensity Distribution ◽  
Light Emitting ◽  
Led Light ◽  
Uv Led ◽  
Freeform Lens

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units

2007 ◽  
Vol 8 (2) ◽  
pp. 35-42 ◽  
Author(s):  
Fabrício Aulo Ogliari ◽  
Ulisses Bastos Campregher ◽  
Susana Maria Werner Samuel ◽  
Carmen Beatriz Borges Fortes ◽  
Alberth David Correa Medina ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Second Generation ◽  
Light Emitting Diode ◽  
Strength Properties ◽  
Knoop Hardness ◽  
Curing Time ◽  
Light Emitting ◽  
Led Light ◽  
Three Samples ◽  
Light Curing

Abstract Aim The purpose of this study was to evaluate the effectiveness of three commercially available light emitting diode (LED) light curing units (LCU) (Elipar FreeLight - 3M ESPE; UltraLume LED2 - Ultradent; and Single V - BioArt) for polymerizing Z250-A3 composite (3M ESPE) using Knoop hardness, polymerization depth, and flexural strength properties. Methods and Materials The XL 2500 (3M ESPE) LCU, which is a conventional halogen unit, was used as a control. In all cases the curing time was 20 seconds. Hardness was determined 24 hours after composite cure for 10 samples of 8 mm diameter and 2 mm height for each LCU tested. Samples were stored dry in a lightproof container prior to testing. The depth of cure of the composite was measured immediately after composite polymerization for each LCU using three samples 4 mm in diameter and 6 mm in height. Flexural strength was determined for five samples 24 hours after immersion in distilled water at 37°C. Each sample measured 25 mm in length, 2 mm in width, and 2 mm in height for each LCU tested. Conclusion The results were treated statistically for comparison of the LCUs. In all cases the results obtained by LED LCUs were not different or were higher than a conventional halogen LCU. Clinical Significance Second generation LED LCUs were as effective as/or more effective than a halogen LCU for polymerization of the used composite. The present study shows second generation LEDs have the potential to replace halogen LCUs. Citation Campregher UB, Samuel SMW, Fortes CBB, Medina ADC, Collares FMC, Ogliari FA. Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units. J Contemp Dent Pract 2007 February;(8)2:035-042.

scholarly journals The effect of halogen bulb and light-emitting diode light curing units on temperature increase and fibroblast viability

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1369
Author(s):  
Georgia Memari Trava ◽  
Juliane Almeida Santos ◽  
Lucas Paula Ramos ◽  
Pamela Beatriz Rosário Estevam dos Santos ◽  
Amjad Abu Hasna ◽  
...  
Keyword(s):  
Temperature Increase ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Control Group ◽  
Cytotoxic Effects ◽  
Light Emitting ◽  
Parametric Data ◽  
Light Curing ◽  
Halogen Bulb ◽  
Non Parametric

Background: This study aimed to compare the temperature increase produced by halogen bulb (HAL) and light-emitting diode (LED) light curing units (LCUs) by irradiating dentin discs (0.5 mm and 1 mm thickness), and to evaluate their cytotoxic effects on fibroblast culture in the presence of dentin discs due to the increasing demand on resin composite restorations and teeth bleaching for esthetic purposes. Methods: A total of 20 bovine incisors were used to obtain dentin discs and divided into four experimental groups (n=10): HAL0.5: irradiation with halogen-tungsten bulb Curing Light XL 3000 at an intensity of 470 mW/cm2 over a dentin disc of 0.5 mm; LED0.5: irradiation with LED Optilight Max (GNATUS- Ribeirão Preto, SP, Brazil) at an intensity of 1200 mW/cm2 over a dentin disc of 0.5 mm; HAL1: irradiation as in HAL0.5 but over a dentin disc of 1 mm; LED1: irradiation as in LED0.5 but over a dentin disc of 1 mm. The temperature increase was measured using a digital thermometer and the cytotoxicity was evaluated using an MTT assay with a mouse fibroblast cell line (L929). Parametric Data were analyzed by ANOVA and Tukey and non-parametric data were analyzed by Kruskal Wallis with Conover-Iman for non-parametric data (all with α=0.05). Results: A significant statistical difference was found between the groups HAL0.5 and HAL1 and both were different of LED0.5 and LED1 which presented higher temperature. All the experimental groups were different of the control group (without irradiation), and promoted reduction of cellular viability. Conclusions: HAL LCU promoted a lower temperature change in the dentin compared to LED, regardless of the dentin thickness (0.5-1 mm). Both HAL and LED LCUs decreased fibroblast viability; however, LED promoted more significant cytotoxic effects.

Radiometric and Spectrophotometric Analysis of Third Generation Light-Emitting Diode (LED) Light-Curing Units

2007 ◽  
Vol 8 (2) ◽  
pp. 43-51 ◽  
Author(s):  
Barry M. Owens ◽  
Kelbin H. Rodriguez
Keyword(s):  
Spectral Distribution ◽  
Light Emitting Diode ◽  
Spectrophotometric Analysis ◽  
Battery Life ◽  
Light Sources ◽  
Third Generation ◽  
Light Emitting ◽  
Led Light ◽  
Restorative Materials ◽  
Light Curing

Abstract Aims Light-emitting diode (LED) polymerization of dental restorative materials has become increasingly popular. However, individual light-curing unit (LCU) functions (intensity and/or wavelength emission) may not conform to manufacturer specifications due to quality control issues. The purpose of this study was to evaluate the quality of irradiance, in terms of power density (intensity) and spectral distribution (peak wavelength), emitted from LED and quartz-tungsten halogen (QTH) LCUs in vitro. The battery expenditure of these LED units was also tested. Methods and Materials The intensity and spectral distribution from four third generation LED (Smartlite PS, Coltolux LED, radii Plus, Diopower) and one QTH (Schein Visible Cure) light sources were measured using six different dental curing light meters (Coltolux, Cure Right, Demetron 100, Demetron LED., Hilux, and Light Meter-200) and a visible-ultraviolet light spectrophotometer (Hitachi Elmer-Perkins). The battery life was also plotted for each light source following a 1500 second duration period. The data obtained from radiometric and spectrophotometric analysis was compared to manufacturer specifications. Results Radiometric evaluation revealed LED light units tested did not satisfy manufacturer claims for minimum intensities. Spectral emissions from the LED light sources did meet manufacturer requirements. No clinically appreciable battery drain was evidenced from testing all re-chargeable LED units. Conclusion Despite limitations LED technology appears to be an effective alternative for curing of lightactivated esthetic restorative materials. Additional advantages associated with LED curing lights include ergonomic handling capabilities, negative heat generation, and minimal maintenance concerns. Citation Owens BM, Rodriguez KH. Radiometric and Spectrophotometric Analysis of Third Generation Light- Emitting Diode (LED) Light-Curing Units. J Contemp Dent Pract 2007 February;(8)2:043-051.

scholarly journals Effects of LED Light Color and Intensity on Feather Pecking and Fear Responses of Layer Breeders in Natural Mating Colony Cages

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 814 ◽  
Author(s):  
Haipeng Shi ◽  
Baoming Li ◽  
Qin Tong ◽  
Weichao Zheng ◽  
Dan Zeng ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Low Light ◽  
Light Emitting ◽  
Led Light ◽  
Feather Pecking ◽  
Physiological Indicators ◽  
Light Intensities ◽  
Yellow Orange ◽  
Natural Mating ◽  
Light Color

Natural mating colony cages for layer breeders have become commonplace for layer breeders in China. However, feather pecking (FP) and cannibalism are prominent in this system. The objective of this study was to investigate the effects of four light-emitting diode (LED) light colors (white: WL, red: RL, yellow-orange: YO, blue-green: BG) with two light intensities for each color, on FP, plumage condition, cannibalism, fear, and stress. A total of 32 identical cages were used for the eight treatments (four replicates for each treatment). For both light intensities, hens in RL had a lowest frequency of severe FP, whereas hens in WL had the highest frequency of severe FP. Hens in RL and BG had better plumage conditions than in WL and YO. Compared with RL and BG treatments, hens treated with WL and YO had a significantly longer tonic immobility (TI) duration. Hens treated with RL had a higher concentration of 5-hydroxytryptamine (5-HT), a lower concentration of corticosterone (CORT), and a lower heterophil to lymphocyte ratio than WL and YO. Furthermore, RL could significantly reduce mortality from cannibalism. Overall, hens treated with RL and low light intensity showed a lower frequency of severe FP, less damaged plumage, were less fearful, had lower physiological indicators of stress, and had reduced mortality from cannibalism. Transforming the light color to red or dimming the light could be regarded as an effective method to reduce the risk of FP and alleviate the fear responses of layer breeders.

scholarly journals The Effect of Irradiation Distance on Microhardness of Resin Composites Cured with Different Light Curing Units

2010 ◽  
Vol 04 (04) ◽  
pp. 440-446 ◽  
Author(s):  
Isil Cekic-Nagas ◽  
Ferhan Egilmez ◽  
Gulfem Ergun
Keyword(s):  
Light Emitting Diode ◽  
Resin Composite ◽  
Composite Layer ◽  
Hardness Test ◽  
Resin Composites ◽  
Plasma Arc ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Halogen Light ◽  
Light Curing

Objectives: The aim of this study was to compare the microhardness of five different resin composites at different irradiation distances (2 mm and 9 mm) by using three light curing units (quartz tungsten halogen, light emitting diodes and plasma arc).Methods: A total of 210 disc-shaped samples (2 mm height and 6 mm diameter) were prepared from different resin composites (Simile, Aelite Aesthetic Enamel, Clearfil AP-X, Grandio caps and Filtek Z250). Photoactivation was performed by using quartz tungsten halogen, light emitting diode and plasma arc curing units at two irradiation distances (2 mm and 9 mm). Then the samples (n=7/ per group) were stored dry in dark at 37°C for 24 h. The Vickers hardness test was performed on the resin composite layer with a microhardness tester (Shimadzu HMV). Data were statistically analyzed using nonparametric Kruskal Wallis and Mann-Whitney U tests.Results: Statistical analysis revealed that the resin composite groups, the type of the light curing units and the irradiation distances have significant effects on the microhardness values (P<.05).Conclusions: Light curing unit and irradiation distance are important factors to be considered for obtaining adequate microhardness of different resin composite groups. (Eur J Dent 2010;4:440-446)

scholarly journals Operation of LED Light as Emergency Lighting Resource DC with Charger Control Based Arduino Uno ATmega

2017 ◽  
Vol 1 (2) ◽  
pp. 13
Author(s):  
I Wayan Rinas ◽  
I Made Suartika ◽  
Anak Agung Maharta Pemayun ◽  
I G. A. P. Raka Agung
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Human Life ◽  
Life Time ◽  
Power Source ◽  
Light Emitting ◽  
Dc Voltage ◽  
Led Light ◽  
Arduino Uno ◽  
Dc Current

Lighting is very important to support the activities of human life. To maintain the continuity of lighting can use power source from genset or battery. Now many manufactured LED (light emitting diode) bulb type which is energy saving with life time up to 50.000 hours. LEDs of this type can be operated with AC and DC current. The design control charger based Arduino Uno ATmega micro controller is used as a control system for charging and turning on LED lights. In this research the measurement of light intensity is done at 220 volt AC as reference, then measured the intensity of light for operation on some variation of DC voltage. The measurement results at DC voltage, LED Osram can be operated at 115 volt DC has reached the same light intensity with 220 volt AC. This selection aims to reduce the amount of battery usage as a DC power source.

scholarly journals Influence of Prolonged Light-curing Time on the Shear Bonding Strength of Resin to Bleached Enamel

2010 ◽  
Vol 35 (6) ◽  
pp. 672-681 ◽  
Author(s):  
M. Hussain ◽  
Y. Wang
Keyword(s):  
Exposure Time ◽  
Bonding Strength ◽  
Clinical Relevance ◽  
Light Exposure ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Curing Time ◽  
Light Emitting ◽  
Light Curing ◽  
Shear Bonding Strength

Clinical Relevance The bonding strength of resin composite to bleached enamel can be enhanced by increasing the light exposure time of light-emitting diode units if bonding is delayed for 24 hours.

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