Comparative analysis of third generation leds used for photoactivation of nanoparticulated compound resins of different colors

Abstract

Properties of composite resins compared to activation sources that emit double wavelengths. This study evaluated the nanohardness (ND), the modulus of elasticity (ME) and degree of monomeric conversion (GC) of two colors (A2 and WE) of the nanoparticulate composite resin Z350XT (3M/ESPE) polymerized by two photoactivating units (Bluephase, Ivoclar/Vivadent and VALO, Ultradent). 24 specimens (CP) were made with a split polypropylene circular matrix surrounded by an aluminum ring (5 mm x 2 mm). The PCs were photoactivated with a light intensity of 1,200 mW / cm2 for 30 seconds and stored in an oven at 37o C, for 24 hours. The ND and ME tests were performed on the DUH211S nanodurometer Shimadzu, with a force of 10 mN and a waiting time of 0 s and the GC test was performed on the IR Prestige21 FTIR Shimadzu, considering 20 scans, 2 cm-1 resolution and wavelength from 4000 to 400. The data were analyzed by ANOVA and Kruskall-Wallis (α = 0.05). The WV group showed superior nanohardness, with a statistically significant difference (p=0.0284). The ME values did not show statistically significant results both when comparing the color effect (p=0.0975 and 0.0777) and that of the activating source (p=0.2189 and 0.1814). The results of the CG showed to be very similar when related to the two variables. Polymerization with the VALO photoactivator unit led to improvements in the nanohardness in the light-colored resin, not being the same observed in relation to the degree of monomeric conversion and the elasticity module.