Copying an upper denture and producing a clear cold cure acrylic base plate with wax teeth.

Copy denture flask.

Firstly the upper denture and both halves of the copy denture flask are lightly vaselined and a reasonable amount of smooth alginate mixed in a rubber bowl.

The flask with the escape holes in it is gradually filled with alginate.

The palatal surface of the upper denture is then covered by the alginate ensuring no air blows.

N.B. As this is a demo piece, protective gloves are not worn at times.  Please follow standard Health & Safety protocol in your laboratory.

The upper denture is then gradually placed 'teeth down' in the flask, until the peripheral edge of the denture is level with the rim of the flask as shown. Do not push the denture too far into the flask, so the teeth touch the bottom of the flask. This will cause complications during the later stages.

Once the alginate has set, a plaster knife is used to cut around the flask / denture to create a flat and smooth joining surface. This is very important as it aids the separation of the two halves of the flasks at a later stage.

The escape holes may also be smoothed off at this stage.

The joining surface is then lightly vaselined.

The mixing of alginate process is then repeated.

Alginate is carefully placed into the fitting surface of the upper denture. Ensure the alginate flows around the fitting surface of the upper denture to minimise air blows.

The other half of the copy denture flask is then filled with alginate as before.

The two halves are then closed and pressed together.

Once set, the excess alginate is cut away with a plaster knife.

The copy denture flask is opened as shown.

The upper denture removed.

The cold cure acrylic resin may now be sprayed onto the fitting surface of the alginate copied upper denture.

Spraying process. Once cured, the base plate is trimmed and smoothed in the usual method.

Escape holes are then cut into the alginate 'teeth side' of the copy denture by using a serrated piece of tubing or similar on both sides as shown.

With the now trimmed base plate in position in the flask, the two halves are held together using an elastic band for the next process.

Wax is melted using a Bunsen burner and wax melting pot or similar.

The wax is then gradually poured into one on the escape holes until the wax appears from the other escape hole and the flask is filled with wax. The flask / wax is allowed to cool / placed in cold water until the wax has set.

The flask is then opened, the acrylic / wax copy denture removed and smoothed with a hot wax knife.

The completed copy denture with acrylic base plate. Original denture also shown.