[Surface structures and substance loss during the etching of ceramic materials]

The progressive development of all-ceramic systems used in prosthetic dentistry gives material-specific aspects a new significance. It was the purpose of this study to examine the surface morphology of various ceramics (Mirage, Dicor, Optec, Vitadur N, Ceramco II) etched with various solutions (Super-Etch, Stripit, hydrofluoric acid 40%, Dicor retention gel) and etching times (1, 2, 3, and 4 min), using a SEM. With the exception of Dicor, the etched surface of ceramics showed similar structures within each material group, regardless of the etching time and the etching solution used. Dicor showed a different pattern depending on the etching time. An additional measurement of the surface roughness revealed an advisable etching time of 1 min with an average loss of ceramic material of 1.6 microns for those ceramics treated with the etching solutions Super-Etch, Stripit and Dicor retention gel. Hydrofluoric acid 40% caused a significant loss of substance and should not be used. A qualitative evaluation of the surface structure of composite cements (Chameleon, Dicor, Optec and Dual cement) in etched ceramics and in etched enamel showed completely filled microretentions.