THE ALTERNATIVE METHOD IN SURFACE MODIFICATION OF DENTAL ZIRCONIA USING HYDROFLUORIC ACID

Abstract

Recently, the use of dental zirconia has become increasing in dentistry because of its excellent mechanical properties, esthetic appearance and biocompatibility. Most studies reported that dental zirconia cannot be etched with hydrofluoric acid (HF). Therefore, the aim of this study was to evaluate the effect of HF treatment on the dental zirconia surface. The experiment was divided into two parts. First part, Can HF alter zirconia surface or not? The HF treatment on zirconia surface was done in different acid concentrations, temperatures, and times. The results by using SEM, EDS evaluations showed that treated zirconia appeared to have irregularity surfaces. . In addition, there was the deposition of fluorine element on zirconia surface as well. After using ICP analysis the dislodged zirconium element was found in an immersed HF solution. Second part, the physical properties of HF treated zirconia were evaluated by using profilometer, AFM, FTIR, XRD, and XPS. The roughness values of the etched specimens as examined by profilometer and AFM increased comparing with control group. By using FTIR, XRD, and XPS analyses, it was found that tetragonal-to-monoclinic phase transformation was induced and the chemical reaction between HF and zirconium oxide occurred. The results of this study concluded that dental zirconia can be etched by hydrofluoric acid, creating the change of surface morphology. In addition, low temperature degradation was occurred. Furthermore, the chemical reaction between HF and zirconia was confirmed.