IADR Abstract Archives
Grinding Behavior of a Novel Esthetic Full-Contour Zirconia
Objectives: In this study the grinding behavior of sintered CAD/CAM zirconia restoration materials was investigated in a standardized in vitro test setup that simulates clinical procedures. The result gives an indication about the ease of adjustment and removal of restorations made from the different materials.
Methods: Sample bars (n=5) were cut from 3M Lava Plus High Translucency Zirconia (LPZ) and a novel material 3M Lava Esthetic Fluorescent Full-Contour Zirconia (LEZ). Samples of both materials were sintered according to instructions to final dimensions of l=17 mm w=1.25 mm h=6 mm. Each sample was placed in a longitudinal moving abrasion test device (Elcometer 1720) allowing a free mobility in z-direction to apply a constant load of 2.6 N. The sample side (l*w) was moved back and forth (path length L=9.8 mm, frequency f=120 cycles/min for a time t=30 s) over a orthogonally fixed dental turbine handpiece (KaVo INTRAsurg 300 with W&H WS-92 E/3 handpiece) with a red ring diamond cylinder (edenta diamond instruments FG K881.016) running constantly at 108000 rpm with water cooling. The grinding profile and sample width were measured with a laser scanning microscope (Keyence VK-X200) and the amount of removed zirconia material was calculated.
Results: The removed zirconia volumes (dV) are summarized in Table 1. 2-sample-t-test (p<0.05) was performed for LPZ and LEZ. dV is significantly higher for LEZ compared to LPZ.
Conclusions: In this standardized grinding experiment it has been shown that higher volumes are removed from LEZ compared to LPZ with a diamond tool at similar time and load. The result reveals that LEZ is easier to grind compared to LPZ in clinical situations. This suggests an advantage if contact points of restorations have to be adjusted or when restorations have to be removed.
Methods: Sample bars (n=5) were cut from 3M Lava Plus High Translucency Zirconia (LPZ) and a novel material 3M Lava Esthetic Fluorescent Full-Contour Zirconia (LEZ). Samples of both materials were sintered according to instructions to final dimensions of l=17 mm w=1.25 mm h=6 mm. Each sample was placed in a longitudinal moving abrasion test device (Elcometer 1720) allowing a free mobility in z-direction to apply a constant load of 2.6 N. The sample side (l*w) was moved back and forth (path length L=9.8 mm, frequency f=120 cycles/min for a time t=30 s) over a orthogonally fixed dental turbine handpiece (KaVo INTRAsurg 300 with W&H WS-92 E/3 handpiece) with a red ring diamond cylinder (edenta diamond instruments FG K881.016) running constantly at 108000 rpm with water cooling. The grinding profile and sample width were measured with a laser scanning microscope (Keyence VK-X200) and the amount of removed zirconia material was calculated.
Results: The removed zirconia volumes (dV) are summarized in Table 1. 2-sample-t-test (p<0.05) was performed for LPZ and LEZ. dV is significantly higher for LEZ compared to LPZ.
Conclusions: In this standardized grinding experiment it has been shown that higher volumes are removed from LEZ compared to LPZ with a diamond tool at similar time and load. The result reveals that LEZ is easier to grind compared to LPZ in clinical situations. This suggests an advantage if contact points of restorations have to be adjusted or when restorations have to be removed.
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