Typical SEM photomicrographs of (a) a Vickers indent at the enamel nanocomposite zone, (b) crack propagation near DEJ zone at higher magnification, (c) a Vickers indent at dentin zone very near to the DEJ zone, (d) a Vickers indent at dentin zone, (e) crack arrest for cracks from a Vickers indent very near to the DEJ zone, and (f) a Vickers indent at the DEJ zone.