Abstract:

Objective To evaluate the influence of different surface treatments on porcelain surface topography. Methods  Metal ceramic prostheses in 6 groups were treated according to the different surface treatment methods, and the surface topography was observed through scanning electron microscope（SEM）. Group A was the control one （untreated）, group B was etched by 9.6％ hydrofluoric acid（HF）, group C was deglazed by grinding and then etched by 9.6% HF, group D was treated with Nd: YAG laser irradiation（0.75 W） and HF etching, group E was treated with Nd: YAG laser irradiation（1.05 W） and HF etching, and group F was treated with laser irradiation（1.45 W） and HF etching. Results  Surface topography was different in different groups. A lot of inerratic cracks with the shapes of rhombuses and grid, and crater with a shape of circle were observed on the ceramic surface after treatment with energy
parameters of 1.05 W Nd: YAG laser irradiation and 9.6% HF etching（group E）. Surface topography showed a lot of concaves on the inner wall of the cracks, and the concaves with diameter of 1-5 μm could be observed on the inner wall of the holes, which had a diameter of 20 μm under SEM. Conclusion The use of Nd: YAG laser irradiation with the energy parameters of 1.05 W and the HF with a concentration of 9.6% can evenly coarsen the porcelain surface, that is an effective surface treatment method.

Key words:  surface treatment, scanning electron microscope, hydrofluoric acid, Nd: YAG laser