Preparations and materials for dental purposes, including plastics in the form of pastes or powders and materials mainly consisting of plastics in the form of pastes or powders for tooth crowns, tooth bridges, artificial teeth and plastic prostheses; plastics for use as modelling material for dental uses, embedding materials for dental uses; doubling materials for dental uses, impression materials for dental uses, dental fillers, dental cement, dental lacquers, insulating material for dental uses, namelysuch for gypsum models for the manufacture of plastic tooth prostheses, and all other goods in this class