According to the literature the ceramic crowns are damaged in 1%-9% of the cases. In order to repair the damage with polimers, first the exposed surfaces have to be made microretentive. Our aim was to investigate with scanning electronmicroscope how the different surface treatment methods modify the structure of metal and ceramic surfaces. We applied two different methods of grinding: 40 microns grained diamond, K1 burs stone (SILISTOR) for ceramic and metal surfaces. The third surface treatment was the application of HF acid for ceramic surface and the sandblasting for metal surface. To achieve microretention the latter mentioned methods increased the most the retentive surface.