Effect of LED-LCU light irradiance distribution on mechanical properties of resin based materials

Filho, Toledo; Weig, Karin; Costa, Márcio Henrique Sá Netto; Werneck, Marcelo Martins; Barthem, R.B.; Neto, Carlos Andrade

doi:10.1016/j.msec.2016.02.060

Cited by 19 publications

(10 citation statements)

References 28 publications

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“…While light beams of broadband QTH sources show no evidence of spectral inhomogeneity, polywave dental LED units may have a spatially inhomogeneous spectral output [8,24]. The effect of this inhomogeneity has been the subject of several studies, and there is debate about the influence of this on material properties [25][26][27][28]. Some authors report steep differences in material surface properties locally depending on light distribution [25][26][27].…”

Section: Plos Onementioning

confidence: 99%

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On the inaccuracies of dental radiometers

Shortall

Palin

2021

PLoS ONE

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This study investigated the accuracy of sixteen models of commercial dental radiometers (DR) in measuring the output of thirty-eight LED light curing units (LCUs) compared with a 'gold standard' laboratory-grade spectrometer integrating-sphere (IS) assembly. Nineteen Type I (fiber-bundle light guide) and nineteen Type II (light source in head) LED LCUs were tested, some using different output modes and light guides, resulting in 61 test subsets per radiometer. Gold standard (GS) output measurements (n = 3) were taken using the IS and confirmed with two types of laboratory-grade power meter (PowerMax-Pro 150 HD and PM10-19C; Coherent). One DR (Bluephase Meter II, Ivoclar; BM II) allowed power (mW) as well as irradiance (mW/cm2) recordings. Irradiance readings (n = 3) for each DR/LCU were compared with the IS derived irradiance. Individual LCU irradiance values were normalized against IS data. The GS method yielded reproducible data with a 0.4% pooled coefficient of variation for the LCUs. Mean power values ranged from 0.19 W to 2.40 W. Overall power values for the laboratory-grade power meters were within 5% of GS values. Individual LCU/DR normalized irradiance values ranged from 7% to 535% of the GS; an order of magnitude greater than previous reports. BM II was the only radiometer to average within 20% of normalized pooled GS irradiance values, whereas other radiometers differed by up to 85%. Ten radiometers failed to provide any reading for 1 LCU. When tested with the PowerMax-Pro in high speed (20 kHz) mode, eight LCUs demonstrated pulsing outputs undetectable at the standard (10 Hz) data acquisition rate. Sufficient light exposure is critical for the successful curing of dental resin-based materials. Substantial discrepancies may occur between actual and estimated radiometric data using current DRs. More accurate DRs need to be developed. Manufacturers' accuracy claims for DRs should specify compatible LCUs and testing parameters.

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Section: Plos Onementioning

confidence: 99%

“…The effect of this inhomogeneity has been the subject of several studies, and there is debate about the influence of this on material properties [25][26][27][28]. Some authors report steep differences in material surface properties locally depending on light distribution [25][26][27]. In contrast, others cannot find any such effect [28].…”

Section: Plos Onementioning

confidence: 99%

On the inaccuracies of dental radiometers

Shortall

Palin

2021

PLoS ONE

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“…Magalhaes Filho et al (2016), discussing this factor, stated that physical properties of the RBC are affected mainly by the local power, wavelength, and beam power profile of the LCU used, and concluded that, with the current advanced development of the new LED units and the declining usage of QTH units (mainly owing to a shortage of spare parts and maintenance capacity), the LED unit, preferably its polywave system, is the method of choice to cover a broader range and activate more photoinitiators (Magalhaes Filho et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Factors affecting polymerization of resin-based composites: A literature review

AlShaafi

2017

The Saudi Dental Journal

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“…The author recommends positioning the detector close to the source to ensure that measurements are taken with the minimum radius of the laser beam and to ensure the measurement of the maximum power value. There are also other approximations of direct calculations in which the efficiency of radiation in the LEDs is studied for example, Magalhães et al (2016) investigated the effect of different LED arrangements, placed on a disc with a diameter of 70mm and compared the different configurations such as: radial arrays, diamonds, square radials, and square diamonds. This study was conducted by optical simulation, in which the researchers concluded that square radial and radial matrices had better efficiency.…”

Section: Introductionmentioning

confidence: 99%

Experimental evaluation of the effect of spatial position on the power of a 5W LED

2020

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This experiment evaluates the effect of the spatial position on the power of a 5W LED which was obtained using a radiometer. For this purpose, the radiant flow emitted by the LED was arranged, taken at different positioning angles and the distance from it from the sensing equipment. Statistical analysis for the validation of the obtained data was checked against the values provided by the manufacturer according to the specification sheet. Finally, the increase in tilt angle and distance resulted in a loss of radiant flow emitted by the LED by 99%.

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Effect of LED-LCU light irradiance distribution on mechanical properties of resin based materials

Cited by 19 publications

References 28 publications

On the inaccuracies of dental radiometers

On the inaccuracies of dental radiometers

Factors affecting polymerization of resin-based composites: A literature review

Experimental evaluation of the effect of spatial position on the power of a 5W LED

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