The following sequence of images show a traditional wax preparation on a high specification die. This is used in metal casting.
Margins are highlighted with a red margin wax, and "die hardened" at the die trimming stage. Die hardener seals the otherwise porous plaster. Undercuts are in-filled, using blocking out wax, and three layers of die spacer, gold and silver, are applied by brush.
Dies are dipped into a hot wax bath, and an exposed collar of grey wax, is added along with any extra porcelain support that is needed. Finally a wax sprue is added, at the correct angle, to allow optimum metal flow.
There are also more advanced techniques which are used in the construction of more complex cases e.g. Wax pattern making for bridge work and second stage casting.
We start with a hardened Die. It has been coated, so it is no longer porous. Its margins have been highlighted (red).
Die Spacer
A Die spacer is applied by brush (the silver coating seen in this image). This thin layer is to make allowance for the adhesive that will be applied later, when the crown is fixed into place in the patients mouth.
Dip in Wax and Removing Excess Wax Material
The Die is dipped into hot wax. After dipping, it is allowed to cool and then the excess wax is removed by hand.
Wax Coping Formed
The new wax layer forms the coping which will later be burnt away in the metal casting process.
Die with Wax Collar
A wax collar is added to the wax coping. This allows for a slightly wider metal substructure at the rear of the crown. This will be trimmed back later.
