The cleaner and more precise the construction of the wax pattern the easier and less time consuming the metal framework will be to finish and polish. If necessary, additional plastic retention pins can be adapted to the loop retention in order to improve fixation of the acrylic denture teeth later.

Two or three sprues can be adapted according to the extent of the wax pattern. The amount of sprues also depends upon the torque and centrifuge.

For an upper denture preferably use 3.5 mm sprues! The best place to connect the sprues is the transition between base and retention.

The funnel shaped sprue former must be securely waxed in place. The molt should be able to enter the mould without danger of tearing investment material from the sides.

The funnel shaped sprue former should be situated slightly higher than the highest point of the wax pattern. The model is waxed centrally onto the base former.

In order to avoid the formation of ascending bubbles, spray the model with distilled water. This prohibits air bubbles from leaving the unhardened model.