(A) Modelling pastes.
These are plastic preparations generally used by artists or goldsmiths for making models and also by children for amusement purposes. The most common are those with a basis of zinc oleate. These also contain waxes, white oil and kaolin and are slightly greasy to the touch. Others are mixtures of cellulose pulp and kaolin with binders. These pastes are usually coloured and are presented in bulk or in cakes, sticks, plates, etc. Assorted modelling pastes, including those put up in sets for the amusement of children, are also covered by this heading.(B) Preparations known as "dental wax" or as "dental impression compounds". These are preparations of varying composition used in dentistry for taking dental impressions. They consist generally of wax, plastics or gutta-percha, mixed with products such as rosin, shellac and fillers (e.g., powdered mica) and are usually coloured. They may be hard or slightly soft. These preparations are classified here only if put up in sets, in packings for retail sale or in plates, horseshoe shapes (solid or hollowed), sticks or similar forms. When put up otherwise (e.g., in bulk), they are classified according to their composition (headings 34.04, 38.24, etc.). (C) Other preparations for use in dentistry, with a basis of plaster (of calcined gypsum or calcium sulphate). This heading includes preparations for use in dentistry with a basis of plaster, usually containing more than 2% of additives by weight. Possible additives are titanium dioxide as a white pigment, colouring agents, kieselguhr, dextrins and melamine resin. They also contain setting accelerators or retarders. Such products for use in dentistry generally contain 25% or more by weight of ¥á-calcium sulphate hemihydrate or almost exclusively ¥á-calcium sulphate hemihydrate, a form that does not occur naturally and that can be produced, e.g., by dehydration of gypsum deposits with a high calcium sulphate dihydrate content. The products are used for taking dental impressions, for making models or for other dental uses and are classified here regardless of form or presentation. Such preparations should not be confused with the plasters which contain small quantities of accelerators or retarders only (heading 25.20). The heading excludes dental cements and other dental fillings (heading 30.06).
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