Ahmed El Gamal1, Jean Paul Rocca1, Carlo Fornaini1,2, Etienne Medioni1, Nathalie Brulat-Bouchard3. 1. Micoralis laboratory EA 7354, University Côte d'Azur, Nice, France. 2. Group of Applied ElectroMagnetics, Information Engineering Department, University of Parma, Italy. 3. Mines ParisTech-Centre de Mise en Forme des Matériaux (CEMEF), CNRS-UMR 7635, Sophia Antipolis, France.
Abstract
BACKGROUND AND AIMS: The aim of this study was to measure the microhardness values of irradiated computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics surfaces before and after thermal treatment. MATERIALS AND METHODS: Sixty CAD/CAM ceramic discs were prepared and grouped by material, i.e. lithium disilicate ceramic (Emax CAD) and zirconia ceramic (Emax ZirCAD). Laser irradiation at the material surface was performed with a carbon dioxide laser at 5 Watt (W) or 10 W power in continuous mode (CW mode), or with a neodymium:yttrium aluminum perovskite (Nd:YAP) laser at 10 W on graphite and non-graphite surfaces. Vickers hardness was tested at 0.3 kgf for lithium disilicate and 1 kgf for zirconia. RESULTS: Emax CAD irradiated with CO2 at 5 W increased microhardness by 6.32 GPa whereas Emax ZirCAD irradiated with Nd:YAP decreased microhardness by 17.46 GPa. CONCLUSION: CO2 laser effectively increases the microhardness of lithium disilicate ceramics (Emax CAD).
BACKGROUND AND AIMS: The aim of this study was to measure the microhardness values of irradiated computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics surfaces before and after thermal treatment. MATERIALS AND METHODS: Sixty CAD/CAM ceramic discs were prepared and grouped by material, i.e. lithium disilicate ceramic (Emax CAD) and zirconia ceramic (Emax ZirCAD). Laser irradiation at the material surface was performed with a carbon dioxide laser at 5 Watt (W) or 10 W power in continuous mode (CW mode), or with a neodymium:yttrium aluminum perovskite (Nd:YAP) laser at 10 W on graphite and non-graphite surfaces. Vickers hardness was tested at 0.3 kgf for lithium disilicate and 1 kgf for zirconia. RESULTS: Emax CAD irradiated with CO2 at 5 W increased microhardness by 6.32 GPa whereas Emax ZirCAD irradiated with Nd:YAP decreased microhardness by 17.46 GPa. CONCLUSION:CO2 laser effectively increases the microhardness of lithium disilicate ceramics (Emax CAD).
Entities:
Keywords:
CAD/CAM ceramic; CO2 laser; Microhardness; Nd:YAP laser