Influence of bulk-fill composite types, shades and lightcuring units on microhardness

Abstract

Aim: The aim of this study was to investigate the microhardness of sonic-activated and high-viscosity bulk-fill resin-basedcomposites (RBCs) in different shades polymerized by using two different light emitting diode (LED) light curing units (LCUs).Material and Methods: Eight groups (n=4) of composite samples with two different shades (A2, A3) of sonic-activated bulk-fill RBCs(SonicFill™) and high-viscosity bulk-fill RBCs (Reveal HD Bulk) were prepared to evaluate the Vickers microhardness (VMH) values.To collect microhardness data for both the upper and the lower sample surfaces, the cylindrical bulk-fill RBC samples with a depthof 4 mm and diameter of 10 mm were cured with two different LED LCUs (Valo Ultradent, Ultradent Products Inc., South Jordan, UT;Demi Ultra, Kerr Dental, USA) with the light-guide tip positioned in contact with a glass slide on the upper surface of the samples.Three-way ANOVA and Student’s t-test analyses were performed with the results obtained. Comparisons were performed using asignificance level of p