Abstract:
This study compared commercial composite resin blocks, composite ceramic block and ceramic block for use in computer-aided design/computer aided manufacturing (CAD/CAM). Flexural strength (FS), flexural modulus (FM), Vicker hardness (VH), two- and three-body wear and discoloration were determined. The data was statistically analyzed using analysis of variance (ANOVA), Tukey’s HSD multiple comparisons and pair t test (α=0.05). After dry storage, FS ranged from 127 to 242 MPa, FM from 9.6 to 51.5 GPa, and VH ranged from 64 to 455. The specimens were tested in a ball-on-disc wear device fitted with a zirconia ball (50 N loads, 1.2 Hz, 50 k cycles) in water for two-body and in poppy seed slurry for three-body wear evaluation. Two-body wear for composite resin blocks was small, hybrid ceramic and ceramic blocks showed greater volume loss. Three-body wear was very low for all materials. The color differences (ΔEs) after immersion in coffee of all materials were significantly greater than those after immersion in water. The discoloration found was extrinsic and could be removed effectively in most case with prophylaxis paste polishing. The composite resin blocks for CAD/CAM are considered suitable for fabrication of singles full crown restorations on premolar teeth.
