The sequence of images above show some of the stages involved in creating gold based restorations: From pattern making to the end product.
Wax Patterns
First wax patterns are formed (or sculpted) by hand. They are attached to a ring former base using red, preformed wax bars. These form the channels or flutes, into which the molten metal will flow.
Investment Process
An outer sleeve is placed over the wax pattern, creating a tight seal with the ring formers base.
Investing Material
Investing material is mixed and poured into the ring former and allowed to set. The outer parts of the ring former are then removed and the remaining hardened plaster becomes the investment ring or mould.
Wax Burnt Away
The investment ring is placed in a burn-out furnace to burn out the wax pattern which is still inside.
Molten Metal
Using a gas torch, precious metal is melted into a crucible prior to it being cast.
Metal Casting
With the impression ring placed in situ with the crucible on a centrifuge; centrifugal force then transfers molten metal into the mould.
Cast Metal Cools
The molten metal is then allowed to cool.
Sand Blast
Finally the investment material is sand blasted away from the metal cast.
Metal Form Prior to Finishing
The cast is then sent to be hand finished and polished.
Final Crowns and Bridges
The end result can be a set of full gold crowns, or a metal supported bridge, or a combination of both, as seen in this image.
