Acid etch technique is now widely used for most compositerestorations as a means of aiding retention and reducing or preventingmicro leakage. For class-4 cavities the acid etches technique hasreplaced the gold inlay as the treatment of choice for restoring thetooth contours and function.Bonding of resins using the acid etch technique has also beenused as a means of splinting teeth which have been weakened bycavity preparation.