- Retentive plastics is a special plastic that burns cleanly without leaving any residue, which avoids porosity in the foundry. - The calcinable plastic pins are necessary for post and wrist repair and are used when there is an inadequate dental structure remaining to support the traditional restoration. - The head of the pins are inverted cones in addition to rough ones ideal to provide a key in the impression. **For further product information, please contact Chat Support**