[Experimental study on the stimulation effect of temperature and capsaicin on oral mucosa of rats].

Purpose: This study evaluated the effect of hot etching with two acid solutions on the surface topography and bond strength of zirconia.

Methods: Firstly, twenty-four pieces of zirconia with a size of 10 mm×10 mm×2 mm and 20 pieces of zirconia with a size of 3 mm×3 mm×2 mm were prepared. Then pieces were divided into four groups, and dealt with separately according to the following groups: no treatment (group A), sandblasting (group B), hot etching with HCl(group C), hot etching with HF(group D). Finally, the surface topography and bond strength were tested by atomic force microscopy(AFM), scanning electron microscope(SEM), X-ray diffraction(XRD) and universal testing machine, etc. Statistical analysis of the experimental data was performed with SPSS 26.0 software package. The final results of XRD were analyzed using MDI Jade 6 combined with Origin 2019 software.

Results: Groups C and D produced completely different topographical changes on the surface of zirconia than group B. Obvious interfacial cracks were observed in group B. Group D achieved the highest roughness value (78.17±4.94) nm and highest shear bond strength (25.09±4.09) MPa.

Conclusions: Compared with HCl, hot etching with HF could achieve more uniform and dense porous morphology, greater roughness and shear bond strength. There were no obvious cross-section interfacial cracks and crystal phase transformations on the surface of zirconia.