Microhardness evaluations of CAD/CAM ceramics irradiated with CO₂ or Nd:YAP laser

Ahmed El Gamal (1) , Jean Paul Rocca (1) , Carlo Fornaini (1) , Etienne Medioni (1) , Brulat-Bouchard Nathalie (2)

1 MICORALIS - Microbiologie Orale, Immunothérapie et Santé
2 CEMEF - Centre de Mise en Forme des Matériaux

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. Material 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).

Mots clés: CAD/CAM ceramic; CO2 laser; Microhardness; Nd:YAP laser

Domaines: Sciences de l'ingénieur [physics]; Matériaux

Ahmed El Gamal, Jean Paul Rocca, Carlo Fornaini, Etienne Medioni, Brulat-Bouchard Nathalie. Microhardness evaluations of CAD/CAM ceramics irradiated with CO₂ or Nd:YAP laser. Laser Therapy, 2017, 26 (1), pp.13 - 18. ⟨10.5978/islsm.17-OR-01⟩. ⟨hal-01512624⟩