Wear resistance of crowns made from different CAM/CAD materials

• Published in: Dental materials 2021-07, Vol.37 (7), p.e407-e413
• Main Authors: Wille, Sebastian, Sieper, Kim, Kern, Matthias
• Format: Article
• Language: English
• Subjects: Ceramic; Dentistry; Lithium disilicate; PICN; Wear; Zirconia-reinforced lithium silicate
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2021.03.017

•PICN has high wear resistance against steatite antagonist.•Low impact on surface roughness for PICN by wear.•Zirconia reinforced lithium disilicate is less abrasive against steatite. The aim of this laboratory study was to evaluate the wear resistance of crowns made from current computer-aided design and computer-aided manufacture (CAD/CAM) materials. In addition, the abrasion of the steatite antagonist against these materials was compared. Identically shaped crowns of lithium disilicate, zirconia-reinforced lithium disilicate and a polymer-infiltrated ceramic network (PICN) were fabricated with an occlusal thickness of 1.5mm and a lateral wall thickness of 1.2mm (n=8). The crowns were cemented with a dual-polymerizing luting resin on composite resin dies. Using spherical steatite antagonists, all specimens were loaded with 49N for 1,200,000 cycles in a mastication simulator with additional thermocycling. After 120,000, 240,000, 480,000, 960,000, and 1,200,000 cycles, precision impressions were made and investigated with a laser scanning microscope. The vertical and volume substance loss was measured. Additionally, the substance loss of the antagonists was evaluated after 1,200,000 loading cycles. No significant difference (p>0.05) was found in the median volume loss of the test materials after 1,200,000 cycles (lithium disilicate: 0.405mm3, PICN: 0.362mm3, zirconia-reinforced lithium disilicate: 0.340mm3). The vertical substance loss of PICN (157μm) was significantly lower (p≤0.05) than that of lithium disilicate (201μm) and zirconia reinforced lithium disilicate (191μm). However, the substance loss of steatite against zirconia-reinforced lithium disilicate (0.191mm3) was significantly lower (p≤0.05) than against lithium disilicate (0.296mm3) and PICN (0.531mm3). All three CAD/CAM materials showed wear resistance that seems appropriate for clinical application. Also, the abrasion of the antagonist looks promising.