Title: 0873 - Effects of HF Immersion on Polycrystalline Particulates of Zirconia Surface


Zutai Zhang (Presenter)
School of Stomatology, Capital Medical University

Yueming Tian, School of Stomatology, Capital Medical University
Dongxiang Zheng, Capital Medical University
Ning Dinig, School of Stomatology, Capital Medical University


Objectives: Zirconia ceramics have been widely used in dentistry. In previous study, in situ synthesized polycrystalline particulates on zirconia surface improved the bonding strength of resin to zirconia ceramic (YM Tian et al. Applied Surface Science 2015, 357: 961–967). This study aimed to investigate the effects of HF immersing time on synthesized polycrystalline particulates of zirconia surface

Methods: Yttrium-stabilized tetragonal zirconia discs (16 mm*1.5 mm) were cut from prefabricated zirconia blocks and polished to 1200# silicone-carbide paper. Based on the immersion time of zirconia disc in HF solution, zirconia samples were divided into seven groups: C, without treatment; F1, F3, F5, F7, F9, and F11, immersed in the HF solution for 10s, 30s, 50s, 70s, 90s, and 110s, respectively. Then, samples were put into CaCl2 solution (0.1 mol/L) for 90 s, dipped in NaOH solution from 20°C to 80°C in a water bath, and kept at 80°C for 2 h. After final sintering (1450°C), SEM observation was performed, and the average surface roughness (Ra) were also measured with a surface-texture and contour measuring instrument. The average values (Ra) were statistically analyzed with one-way ANOVA (α= 0.05).

Results: The SEM images showed octahedral polycrystalline particulates were formed on the tested groups, and became dense with the prolongation of immersion time in HF. The surface roughness and standard deviation values of the groups were C: 0.114±0.022, I1: 0.366±0.086, F3: 0.876±0.064, F5: 1.151±0.296, F7:1.400±0.342, F9:1.510±0.194, and F11: 0.994±0.379 μm, respectively, and the value was increased with the immersion time until F9, and there was significant differences among group C, I1, F3, F5 and F7 (P<0.05).

Conclusions: Polycrystalline particulates on zirconia surface became dense with the prolongation of immersion time in HF. However, the surface roughness was not always increased.

This abstract is based on research that was funded entirely or partially by an outside source:
This study was supported by the National Natural Science Foundation of China (Grant No. 81671027 & 81371175)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE