Mateus Garcia Rocha, Jean-François Roulet, Mario Alexandre Coelho Sinhoreti, Américo Bortolazzo Correr, Dayane Oliveira
Brazilian dental journal 2021 Jan-FebThe objective of this study was to evaluate the effect of the exposure reciprocity law of a multi-wave light-emitting diode (LED) on the light transmittance (LT), depth of cure (DOC) and degree of conversion in-depth (DC) of a bulk fill composite. A bulk fill composite (EvoCeram® bulk fill, Ivoclar Vivadent) was photoactivated using the multi-wave LED (VALO™ Cordless, Ultradent). The LED was previously characterized using a spectrophotometer to standardize the time of exposure when using the Standard or Xtra-Power modes with the same radiant exposure of 20J/cm2. LT was evaluated through samples of the bulk fill composite every millimeter till 4 mm in-depth. DOC was evaluated according to the ISO 4049. DC of the central longitudinal cross-section from each sample of the DOC test was mapped using FT-NIR microscopy. Data were statistically analyzed according to the experimental design (α=0.05; ß=0.2). The radiant exposure in the violet wavelength range for Standard and Xtra-Power was 4.5 and 5.0 J/cm2, respectively; for the blue wavelength range the radiant exposure for Standard and Xtra-Power was 15.5 and 15.0 J/cm2, respectively. There was no statistical difference in the DOC using Standard or Xtra-Power light-curing modes, but the DOC was lower than the claimed by the manufacturer (4 mm). The DC was not significantly affected by the light-curing mode up to 4 mm in depth (p>0.05). According to exposure reciprocity law, the reduction in exposure time using the same radiant exposure did not affect the depth of cure of the bulk fill composite.
Mateus Garcia Rocha, Jean-François Roulet, Mario Alexandre Coelho Sinhoreti, Américo Bortolazzo Correr, Dayane Oliveira. Light Transmittance and Depth of Cure of a Bulk Fill Composite Based on the Exposure Reciprocity Law. Brazilian dental journal. 2021 Jan-Feb;32(1):78-84
PMID: 33914006
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