IADR Abstract Archives
Wear Resistance of Crowns Made from Current CAD/CAM Materials
Objectives: The aim of this study was to evaluate the wear resistance of crowns made from current CAD/CAM materials. In addition also the abrasion of the used antagonist made of steatite against these three materials was evaluated.
Methods: Identically shaped crowns from lithium disilicate (IPS E.max CAD, Ivoclar Vivadent), zirconia reinforced lithium disilicate (VITA Suprinity) and a hybrid ceramic (VITA Enamic) were fabricated with occlusal thickness of 1.5 mm and lateral wall thickness of 1.2 mm (n=8). Crowns were cemented with Multilink Automix (Ivoclar Vivadent) on composite dies (Z100, 3M ESPE). All 24 samples were loaded with 49N in a chewing-simulator with thermocycling for 1,200,000 cycles in total using spherical steatite antagonists. After 120,000, 240,000, 480,000, 960,000 and 1,200,000 cycles precision impressions (Express 2Ultra-Light Body Quick, 3M ESPE) were made and investigated with a laser scanning microscope (vk-x 100, Keyence). The vertical and volume substance loss was measured. Additionally the substance loss of the antagonists was evaluated after 1,200,000 chewing cycles. The statistical significance was tested with one-way ANOVA and a Post-hoc Tukey-Test.
Results: There was no significant difference in the volume loss of all three tested materials after 1,200,000 cycles (lithium disilicate: 0.396±0.064mm3, hybrid ceramic: 0.400±0.093mm3, zirconia reinforced lithium disilicate: 0.358±0.070mm3, p=0.487). The vertical substance loss of hybrid ceramic (160±34µm) was significantly lower than the loss of lithium disilicate (211±34µm, p=0.011) and zirconia reinforced lithium disilicate (202±27µm, p=0.039). However, the substance loss of the steatite antagonists against zirconia reinforced lithium disilicate (0.195±0.049mm3) was significantly lower than against lithium disilicate (0.414±0.257mm3, p=0.038) and hybrid ceramic (0.531±0.115mm3, p=0.002).
Conclusions: All tested materials showed comparable wear resistance that seems appropriate for clinical applications when lithium disilicate is considered a clinically approved material. Also the caused antagonistic wear seems promising.
This study was supported by Ivoclar Vivadent, 3M ESPE and VITA Zahnfabrik
Methods: Identically shaped crowns from lithium disilicate (IPS E.max CAD, Ivoclar Vivadent), zirconia reinforced lithium disilicate (VITA Suprinity) and a hybrid ceramic (VITA Enamic) were fabricated with occlusal thickness of 1.5 mm and lateral wall thickness of 1.2 mm (n=8). Crowns were cemented with Multilink Automix (Ivoclar Vivadent) on composite dies (Z100, 3M ESPE). All 24 samples were loaded with 49N in a chewing-simulator with thermocycling for 1,200,000 cycles in total using spherical steatite antagonists. After 120,000, 240,000, 480,000, 960,000 and 1,200,000 cycles precision impressions (Express 2Ultra-Light Body Quick, 3M ESPE) were made and investigated with a laser scanning microscope (vk-x 100, Keyence). The vertical and volume substance loss was measured. Additionally the substance loss of the antagonists was evaluated after 1,200,000 chewing cycles. The statistical significance was tested with one-way ANOVA and a Post-hoc Tukey-Test.
Results: There was no significant difference in the volume loss of all three tested materials after 1,200,000 cycles (lithium disilicate: 0.396±0.064mm3, hybrid ceramic: 0.400±0.093mm3, zirconia reinforced lithium disilicate: 0.358±0.070mm3, p=0.487). The vertical substance loss of hybrid ceramic (160±34µm) was significantly lower than the loss of lithium disilicate (211±34µm, p=0.011) and zirconia reinforced lithium disilicate (202±27µm, p=0.039). However, the substance loss of the steatite antagonists against zirconia reinforced lithium disilicate (0.195±0.049mm3) was significantly lower than against lithium disilicate (0.414±0.257mm3, p=0.038) and hybrid ceramic (0.531±0.115mm3, p=0.002).
Conclusions: All tested materials showed comparable wear resistance that seems appropriate for clinical applications when lithium disilicate is considered a clinically approved material. Also the caused antagonistic wear seems promising.
This study was supported by Ivoclar Vivadent, 3M ESPE and VITA Zahnfabrik