CAD–CAM blocks to fabricate semi-direct and indirect restorations are available in different sorts of ceramics as well as composite. Today, the effect of sandblasting composite block surfaces has notthoroughly been investigated.structure of five composite CAD–CAM blocks was investi-gated, in particular to assess(1) the effect of sandblasting ontheir surface topography (2) the effect of sandblasting andsilanization on their bonding receptiveness.