Mechanical Properties of Direct and Indirect Composite Materials Used in Prosthodontics

Abstract

This study was conducted to investigate composite materials using mechanical equipment corresponded to masticatory system composed of two antagonistic parts that simulates bimaxilar contact in occlusion and articulation. The aim of this study was to investigate restorative materials with different chemical properties and to find out which material showed the best mechanical properties. The experiment was conducted using 4 types × 20 specimens of direct resin composite materials and equal number of indirect resin composites (IRCs). The following composites were tested: Tetric (Ivoclar Vivadent), Kerr Herculite XRV (Kerr), Charisma (Heraeus Kulzer), Heliomolar (Ivoclar Vivadent), Artglass (Heraeus Kulzer), Targis/Vectris (Ivoclar Vivadent), Vita Zeta LC (Vita) and Kerr Herculite Lab (Kerr). The universal dimensions of all specimens were 5 mm × 5 mm with 2 mm thickness. This was achieved using silicone molds. A total of 160 specimens (80 direct composite specimens and 80 indirect composite specimens) were tested using tensile testing machine. Artglass showed minimal change in thickness (30.20 ± 23.0 μm) compared to others. The highest change in thickness was found in Heliomolar (86.2 ± 32.6 μm). In the group of direct composite materials, Tetric experienced the lowest thickness change (31.0 ± 8.8 μm), while Charisma showed thickness variation of 65.2 ± 27.3 μm. Among indirect composites, Vita Zeta LC showed the highest value of thickness variation (76.2 ± 31.3 μm). In this experimental study, indirect composite specimens showed superior mechanical performance compared to direct composite specimens highlighted Artglass as the material of choice viewed from mechanical aspect.