EVALUATION OF TRANSLUCENCY PARAMETER AND MICROSTRUCTURAL CHARACTERIZATION OF THREE TYPES OF TRANSLUCENT ZIRCONIA AFTER LASER TREATMENT (AN IN VITRO STUDY)

Objectives: This study evaluates translucency parameter (TP) and microstructural characterization of three types of translucent zirconia (Y-TZP) after Er:YAG laser treatment. Materials and Methods: For this evaluation, test specimens were prepared from Cercon Translucent Zirconia (ht) (Dentsply, Sirona, USA), Cercon High Translucent Zirconia (xt) (Dentsply, Sirona, USA) and Cercon Ultra Translucent Zirconia (xtml) (Dentsply, Sirona, USA) that were divided into control (untreated) group and laser treatment group. Laser treated specimens were subjected to Er:YAG laser with following parameters: wavelength of 2940 nm, frequency of 10 Hz, energy of 200 mj and a power of 2W for 10 seconds. The specimens from both groups were subjected to TP measurements using a spectrophotometer. For the characterization, zirconia discs from each group were analyzed using X-ray diffraction (XRD) and Energy Dispersive X-Ray Analysis (EDX).Results: The results revealed significant decrease in the average TP in all groups after laser surface treatment: (5.65 and 5.32) for groups IA and IB respectively, (8.54 and 8.05) for groups IIA and IIB respectively, and (12.12 and 11.21) for groups IIIA and IIIB, respectively. For XRD analysis, results showed appearance of a monoclinic phase after laser treatment. Elemental composition by EDX analysis showed the presence of Carbon (C), Oxygen (O), Aluminum (Al), Ytteria (Y) and Zirconium (Zr). The results were analyzed using the Kolmogorov-Smirnov test, Shapiro-Wilk test and Two-way ANOVA test (P ≤ 0.05). Conclusion: Er: YAG Laser surface treatment significantly affected the TP and XRD analysis.