casting

what are casts?

a positive replica of upper and lower jaw which is made by an impression

what types of dental casts?

1. study casts

2. master casts

3. refractory casts

4. dies

5. optical (digital) casts

what are study casts?

also known as diagnostic casts, they are produced from primary impressions by pouring it with plaster of Paris. It is used for examination, diagnosis, treatment planning, and for the construction of the special tray

what are master casts?

also known as working casts, it is an accurate replica of the prepared teeth and residual ridge. it is produced from the final impression by pouring it with dental stone. It is used for the construction of the record blocks

what is a refractory cast?

a cast used only for the construction of a metallic denture framework, and it can be a complete or partial restoration

what does a refractory cast need?

double casts are required because the refractory cast is used only for wax-up and metal casting, is often destroyed during the process, and cannot be used for final fitting and subsequent laboratory procedures.

what are dies?

a model produced when an impression is poured with a low-fusing metal, such as zinc or tin. used for crowns and bridges

what are optical or digital casts?

a digital model produced either from a digital impression or by scanning a stone cast, so either intraorally or extraorally.

what is a drawback of extraoral optical casts?

they do not accurately capture soft tissues