Chemical Preparations-Namely, Plastics in the Form of Paste or Powder for the Manufacture of Tooth Crowns, Tooth Bridges, Artificial Teeth and Plastic Prostheses; Plastics as Modelling Material for Dental Uses, Impression Material for Dental Uses, Tooth Fillers, Tooth Lacquers, Insulating Agents for Dental Purposes-Namely, for Gypsum Models for Use in Manufacture of Plastic Prostheses and Injections for Dental Uses