Dental Material 2nd Stage LEC: Investment Materials

1. Should not react with wax and alloys. 2. Should be easily manipulated. 3. The inner surface of the mold should not breakdown at higher temperature. 4. At higher temperature, the investment must not decompose to give off gases that could corrode the surface of the alloy. 5. The investment should have enough expansion to compensate for shrinkage of the wax pattern and the metal that takes place during the casting procedure.

The space in the investment created by the burning of wax is called the mold cavity.

The investment should not decompose at higher temperature to prevent the release of gases that could corrode the surface of the alloy.

<p>A dental casting investment should be porous to allow the air or other gases in the mold cavity to escape easily during the casting procedure.</p> Signup and view all the answers

<p>The investment should have enough expansion to compensate for shrinkage of the wax pattern and the metal during the casting procedure.</p> Signup and view all the answers

<p>Absorption involves the whole volume of the material, while adsorption only involves the surface of the material.</p> Signup and view all the answers

<p>Adsorption is the process in which liquid or gas molecules adhere firmly to the surface of solid or liquid, while absorption is the process in which the molecules penetrate into the liquid or solid material.</p> Signup and view all the answers

<p>Sorption is used as a general term for absorption and adsorption.</p> Signup and view all the answers

<p>Adsorption often precedes absorption.</p> Signup and view all the answers

<p>Adsorption is a surface phenomenon, while absorption involves the whole volume of the material. Understanding these processes is crucial in materials science.</p> Signup and view all the answers