Effect of thickness of CAD/CAM materials on light transmission and resin cement polymerization using a blue light-emitting diode light-curing unit.

Eduardo Fernandes de Castro, Bruna Marin Fronza, Jorge Soto-Montero, Marcelo Giannini, Carlos Tadeu Dos-Santos-Dias, Richard Bengt Price

Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.] 2023 Mar

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Evaluate the effect of thickness of high-translucency (HT) CAD/CAM materials on irradiance and beam profile from a blue light-emitting diode light-curing unit (LCU) and on the degree of conversion (DC) and maximum polymerization rate (Rpmax ) of a light-cured resin cement (LCC). The direct output from the LCU, the light transmission and irradiance ratio (IR) through one conventional composite and nine HT CAD/CAM materials (0.5, 1.0, 1.5, or 2.0-mm thick; n = 5) were measured with a integrating sphere coupled to a spectrometer. The light beam was assessed with a beam profiler camera. The DC at 600 s and the Rpmax of one LCC was determined using a Fourier transform infrared spectrometer (n = 5). Data were analyzed by ANOVA followed by Tukey's tests, and Dunnett's test was also used for irradiance data (α = 0.05). A significant decrease in irradiance through all materials occurred as thickness increased. Thin CAD/CAM materials improved light homogeneity, which decreased with the increase in thickness. The DC of the LCC directly exposed to light was the same as when exposed to 45%, 25%, 15%, or 5% IRs. Rpmax decreased with the decrease in IR. Although the HT CAD/CAM materials reduced the irradiance from the LCU, minor effects were observed in the LCC's DC. Despite the light attenuation of blue light through different CAD/CAM materials that were up to 2-mm thick, the degree of conversion of one brand of light-cured resin cement was clinically acceptable when the LCU was used for 30 s. © 2022 Wiley Periodicals LLC.

Citation

Eduardo Fernandes de Castro, Bruna Marin Fronza, Jorge Soto-Montero, Marcelo Giannini, Carlos Tadeu Dos-Santos-Dias, Richard Bengt Price. Effect of thickness of CAD/CAM materials on light transmission and resin cement polymerization using a blue light-emitting diode light-curing unit. Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.]. 2023 Mar;35(2):368-380