[Action of etching acid on lining materials]

A review was made of the literature concerning intermediate materials for composite resin fillings and the possibilities of ortho-phosphoric acid infiltration. An experimental study was aimed at evaluating the damages caused by the acid action of the etching material on various type of base materials used. In conclusion, various procedures are suggested for composite resin restoration in order to avoid the risks of lesions of the pulp-dentin organ.