CO2 and Nd: YAP lasers irradiation on CAD/CAM Ceramics: SEM, EDS and thermal studies (Part 1)

The aim of this study was to investigate the interaction of infrared light on Computer aided design and Computer aided manufacturing (CAD/CAM) ceramics surfaces. Material and Methods: sixty (CAD/CAM) ceramic discs were prepared and divided into two different groups: lithiumdisilicate ceramics (IPSe.maxCADs) and Zirconia ceramics (IPSe.maxZirCADs). The Laser surface irradiation was performed with Carbon Dioxide laser: 5Watt (W) and 10W, Continuous mode (CW mode) and with Neodymium Yttrium Aluminum Perovskite (Nd:YAP) laser at 10W on graphite and non-graphite surfaces. Surface textures and compositions were examined using scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Thermal elevation was measured during laser irradiation with thermocouple. Results: The SEM observation showed a rough surface plus cracks and fissures on CO2 10W samples and melting areas in Nd: YAP samples, while with CO2 5W smooth and shallow surfaces were observed. EDS illustrated that the laser irradiation did not result in modifications of the chemical composition even if minor changes in the atomic and mass percentage of the components were registered. Thermocouple showed various thermal changes during laser irradiation. Conclusion: CO2 and Nd: YAP lasers modify CAD/CAM surface without chemical composition modifications.