Ibrahim M. Hammouda, Reham M. Abdallah, Mostafa Kamal Mohammed, Ossama B. Abouelatta and Abeer A. El Fallal
Objectives: The aim of this study was to investigate the hardness, morphology and structure of dental porcelain and In-Ceram Alumina after conventional glazing, XeCl excimer and CO2 laser glazing techniques at two energy densities.
Materials and Methods: The materials used were conventional feldspathic porcelain Vitadur N and Vita In-Ceram Alumina. The hardness was measured using Vickers microhardness tester. SEM and X-ray diffraction analysis of the surface structure were conducted to detect the surface changes.
Results: The hardness of the porcelain specimens was not significantly increased with 2 watt CO2 laser and 1.5 Joule/cm2 excimer laser glazing. Also, the hardness of in-ceram alumina was not significantly increased with 2 and 10 watt CO2 laser glazing. On the contrary, the hardness of porcelain was significantly increased with 10 watt CO2 and 6.2 Joule/cm2 excimer lasers, as well as the in-ceram alumina was significantly increased with excimer laser glazing. Scanning electron microscopy declared an increase in homogeneity and smoothness of laser glazed specimens especially those glazed with higher power setting of CO2 laser and higher energy density of excimer laser when compared to the conventionally glazed specimens. X-ray diffraction charts of the control and laser glazed specimens were nearly identical, indicating that laser glazing had no effect on their internal microstructure.
Conclusion: It was concluded that, laser glazing improves the surface hardness and smoothness of ceramic surfaces without affecting their internal structures.
Clinical relevance: Laser technology can be used for glazing of ceramic restorations to improve its properties.
