In dentistry, a mould (using a rubber or alginate compound) of the teeth and gums from which a plaster-of-Paris model is prepared. This model provides a base on which to construct a denture, bridge or dental inlay. A similar process is used in ORTHODONTICS to make dental appliances to correct abnormalities in the positioning of teeth.
n. (in dentistry) a negative imprint (mould) of the teeth and surrounding soft tissues or of a toothless jaw. A soft impression material (e.g. silicone or alginate) is placed over the teeth or jaw and sets within several minutes, producing an elastic mould. Impressions may also be taken with hard-setting materials (e.g. plaster or zinc oxide–eugenol cement). From the impression, a positive reproduction (cast or model) can be made out of plaster or stone. On these are constructed *restorations of teeth, *dentures, or *orthodontic appliances.
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