“…To rule out fractures, cavities, enamel abnormalities, or other flaws, the chosen teeth were visually inspected. In order to get rid of any plaque, blood, or remaining periodontal ligaments, they were scaled by hand scaler (13) . The teeth were prepared by sectioning the crown horizontally to separate the coronal portion from the radicular portion of each tooth under water coolant using low speed double faced diamond disc (Besqualdia -disc NY 11373, USA size 22mm), mounted in a grinding machine (Demco alloy grinder, dental maintenance co., INC..BONSALL, CALIF., U.S.A), after which the crowns were cut in half in a mesiodistal orientation to produce 32 samples (5) .…”