COMPLETE DENTURES



12. MAKING THE MASTER CAST
Beading Problems

A frequent problem arises in the retromolar area (mandibular). The student follows the contours of the impression but does not keep the wax horizontal. The end result is little or no land area. Add an extra thickness of beading wax in the retromolar area.

In the posterior of the maxillary impression the wax strip will be below (about 1mm) the border of the impression, which results in a step up in the model. This will delineate the posterior border of the impression. This is not the posterior border of the denture.

If the posterior border is very thin, simply thicken the border with wax. (Don't add wax to the tissue side.) Then drop down a mm from the tissue side and add your horizontal projection of wax (land area).

Some students erroneously place the beading wax on the same plane as the palatal surface. When the cast is poured, the posterior border is not defined it is simply lengthened artificially.

Since the land area should be 2-3mm wide make the beading wax 4-5mm wide. This will allow for trimming of the cast.

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©1999 by Julius Rosen, D.D.S.