Effect of different storage media on the microhardness and wear resistance of resin-matrix ceramics

This in vitro study evaluated the microhardness and two-body wear of various computer-assisted design and computer-assisted manufacturing (CAD/CAM) resin-matrix ceramic materials stored in different storage media. For each material (Paradigm MZ100, Lava Ultimate, Vita Enamic, and Cerasmart), 40 disk-shaped specimens (8 mm diameter × 3 mm thickness) were prepared and divided into four subgroups (n = 10) according to storage material (artificial saliva, distilled water, 0.02 mol/L citric acid, 3:1 ethanol/water). Following storage at 37°C for 7 days, microhardness was measured with a Knoop test, and wear was measured using a 3D scanner and surface analysis program before and after loading on a chewing simulator (200 000 cycles). Wear values of Vita Enamic were lower in comparison to the other materials tested (P < 0.001). Storage media were found to have a significant effect on material microhardness (P < 0.001), but not on wear (P = 0.820).