All composite blocks revealed a different ultra-structure. Sandblasting increased sur-face roughness and resulted in an irregular surface with some filler exposure. Sandblasting also damaged the surface. When the sandblasted composite blocks were silanized, superior bonding receptiveness in terms of higher bond strength was achieved except for Shofu Block HC.Significance. Sandblasting followed by silanization improved the bond strength to compos-ite CAD–CAM blocks. However, sandblasting may also damage the composite CAD–CAM