Effect of various visible light photoinitiators on the polymerization and color of light-activated resins

Arikawa, Hiroyuki; Takahashi, Hideo; Kanie, Takahito; Ban, Seiji

doi:10.4012/dmj.28.454

Cited by 102 publications

(95 citation statements)

References 19 publications

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“…19 Alternative initiators are activated at different wavelengths that are not provided by the LEDs used, due to the short spectrum of light that they emit, which compromises the curing efficacy of this material. 20 Because manufacturers are usually reluctant to reveal the exact compositions of their products, 21 it is not possible to determine whether this situation explains the current results completely.…”

Section: Discussionmentioning

confidence: 97%

Influence of different shades and LED irradiance on the degree of conversion of composite resins

et al. 2012

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The aim of this study was to evaluate the degree of conversion (DC) of two composite resins with different shades that were light cured by light-emitting diodes (LEDs) of different irradiances. Specimens (5 mm × 2 mm) were prepared with a nanofilled (Filtek Supreme -A2E, A2D, and WE) or microhybrid resin (Opallis -A2E, A2D, and EBleach Low) and were randomly divided into 12 groups (n = 5 each) according to the composite resin and light-curing unit (Elipar FreeLight 2, 1250 mW/ cm²; Ultralume 5, 850 mW/cm²). After 24 h, the DC was measured on two surfaces (top and bottom) with Fourier Transform infrared spectroscopy (FTIR). Data were statistically analyzed with two-way ANOVA and Tukey test (α = 0.05). Statistical differences among the surfaces were observed in all experimental conditions, with higher values on the top surface. The microhybrid resin presented the highest DCs for shades A2E and A2D on the top surface. The LED with higher irradiance promoted better DCs. Taken together, the data indicate that the shade of a composite resin and the irradiance of the light source affect the monomeric conversion of the restorative material.

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Section: Discussionmentioning

confidence: 97%

Influence of different shades and LED irradiance on the degree of conversion of composite resins

et al. 2012

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“…However, the spectral distribution of the output from the curing light source and the maximum absorption peak of a photoinitiator can affect the chemical and physical properties of a given resin. Some resinous photocure or dual cure materials, such as resin cements, may have a lower concentration of camphorquinone or other photoinitiator such as phenyl propanedione [28] (PPD) and monoacrylphosphine oxide [29] (TPO), and sometimes the percentage of photoinitiator is not clarified by the manufacturer because a patent on the product has been applied for. For Panavia F, the manufacturer omits the percentage of the camphorquinone-based photoinitiator system, and the percentage and composition of the photoinitiator component for RelyX ARC is unknown.…”

Section: Discussionmentioning

confidence: 99%

“…Although higher values of irradiance induce greater heat generation, the composite disk attenuated the temperature alteration caused by the LED since the composite had a low thermal conductivity [27,29], and did not affect the degree of conversion of the tested resin cements. The curing unit energy density did not influence the degree of conversion of Panavia F cured without ED primer, since QTH provided a significantly higher degree of conversion than the LED when ED Primer was not used.…”

Section: Discussionmentioning

confidence: 99%

The effect of curing light and chemical catalyst on the degree of conversion of two dual cured resin luting cements

et al. 2010

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The aim of this study was to evaluate the influence of different curing lights and chemical catalysts on the degree of conversion of resin luting cements. A total of 60 disk-shaped specimens of RelyX ARC or Panavia F of diameter 5 mm and thickness 0.5 mm were prepared and the respective chemical catalyst (Scotchbond Multi-Purpose Plus or ED Primer) was added. The specimens were lightcured using different curing units (an argon ion laser, an LED or a quartz-tungsten-halogen light) through shade A2 composite disks of diameter 10 mm and thickness 2 mm. After 24 h of dry storage at 37°C, the degree of conversion of the resin luting cements was measured by Fouriertransformed infrared spectroscopy. For statistical analysis, ANOVA and the Tukey test were used, with p≤0.05. Panavia F when used without catalyst and cured using the LED or the argon ion laser showed degree of conversion values significantly lower than RelyX ARC, with and without catalyst, and cured with any of the light sources. Therefore, the degree of conversion of Panavia F with ED Primer cured with the quartz-tungsten-halogen light was significantly different from that of RelyX ARC regardless of the use of the chemical catalyst and light curing source. In conclusion, RelyX ARC can be cured satisfactorily with the argon ion laser, LED or quartz-tungsten-halogen light with or without a chemical catalyst. To obtain a satisfactory degree of conversion, Panavia F luting cement should be used with ED Primer and cured with halogen light.

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“…Thus, the marked decrease in the light transmittance at shorter wavelengths observed was likely caused by higher scattering of light in the material. The wide and deep trough observed around 470 nm for all materials may have been due to light absorbance by the photoinitiator contained in the materials because the wavelength range was similar to the representative absorbance wavelength range of camphorquinone, a conventional photoinitiator often used in light-activated dental materials 15) . Our previous study reported that the filler particle in the composite resin played an important role for the light transmittance characteristics, including light diffusion characteristics, and color of the material 16) .…”

Section: Discussionmentioning

confidence: 99%

Light transmittance characteristics and refractive indices of light-activated pit and fissure sealants

Arikawa

Shinohara²,

Takahashi

et al. 2010

Dent. Mater. J.

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We examined the light transmittance characteristics and refractive indices of light-activated pit and fissure sealants. Five commercial pit and fissure sealants and human enamel were studied, along with the CIE L*a*b* color values of the materials and enamel. The light transmittance spectra of the pit and fissure sealants showed a similar trend to the enamel, especially at wavelengths below 530 nm. The average light transmittance values from 400 to 500 nm of the materials at 0.5-mm-thick ranged from 10.0% to 40.4%. The refractive indices at 589.3 nm ranged from 1.504 to 1.546, and were approximately 4−8% lower than that of enamel. The measurements for the surface hardness of materials indicate that the light-attenuating effect of enamel and the material itself reduced the polymerization efficiency of the material. For all materials, chromatic a* showed negative and b* showed positive values, as did enamel. Significant differences in light transmittance characteristics and refractive indices between the materials and enamel may affect color matching between them.

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Effect of various visible light photoinitiators on the polymerization and color of light-activated resins

Cited by 102 publications

References 19 publications

Influence of different shades and LED irradiance on the degree of conversion of composite resins

Influence of different shades and LED irradiance on the degree of conversion of composite resins

The effect of curing light and chemical catalyst on the degree of conversion of two dual cured resin luting cements

Light transmittance characteristics and refractive indices of light-activated pit and fissure sealants

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