investment casting
The lost-wax process by which a wax dental pattern is encased in a heat-resistant mould material and subsequently burned out to create a void for molten metal.
Full Definition
Investment casting in dental laboratory practice is the multi-step process of encasing a wax pattern in a phosphate- or gypsum-bonded investment material, allowing it to set, then burning out the wax in a furnace to leave a precise mould cavity. Molten alloy is then forced into the cavity—typically by centrifugal or pressure casting machines—to reproduce the detailed form of the original wax pattern. The quality of the investment mix, the burnout temperature protocol, and the casting machine calibration all critically affect the dimensional accuracy and surface quality of the resultant casting. Editors should note that 'investment casting' is the process, whereas 'investment' alone typically refers to the mould material. This term should not be confused with the financial homonym.
Usage
Usage note: Distinguish 'investment casting' (the process) from 'investment' (the material). In dental laboratory documents, the context usually clarifies which is meant, but editors should verify.
In Context
- "The investment casting cycle for the cobalt-chromium framework required a burnout temperature of 900°C." — Laboratory protocol document
- "Porosity in the final crown was traced back to an incorrect water-to-powder ratio during investment casting." — Failure analysis report