MATERIALS FOR TOOTH CROWNS, TOOTH BRIDGES, ARTIFICIAL TEETH AND PLASTIC PROSTHESES, MODELLING MATERIAL FOR DENTAL USES, EMBEDDING MATERIALS FOR DENTAL USES, DUPLICATING MATERIALS FOR DENTAL USES, IMPRESSION MATERIALS FOR DENTAL USES, MATERIALS FOR TOOTH FILLINGS, DENTAL LACQUERS, DENTAL CEMENT, INSULATING MATERIAL FOR DENTAL USES, NAMELY SUCH FOR GYPSUM MODELS FOR THE MANUFACTURE OF PLASTIC TOOTHPROSTHESES