[An experimental and comparative study of chemical method for etching metal frameworks in adhesive bridge]

Authors studied the best dispensing and the time of nickel base alloy etching gel by using orthogonal design and the scanning electron microscope (SEM) evaluation. Shear bond strengths were compared after treating with metal etching gel, electro-etching, painting KH-570 on the surface of Ni-Cr alloy after treating with the gel. The results showed that the gel was found to be an aqua regia solute gel. The optimum time was 90 mins. Shear stress tests revealed that the highest shear bond strength can be obtained by synthetic methods.