MEASUREMENTS OF VERTICAL DIMENSION OF PROCESSED DENTURES

¹ Pittsburgh, Pa.

1. Methyl methacrylate resin when cured at 1600 F. for 9 hours contracted 0.40 per cent in the vertical dimension.

2. The shape factor of teeth (undercuts, etc.) will add, in varying degree, to the vertical dimension of a denture (ridge to cusp tip), depending upon how firmly the teeth are locked into the investing medium.

3. The shape factor of the denture plus the horizontal linear contraction tends to raise the denture from the cast in the palatal area and over the lingual ridge areas to a very minute degree, adding somewhat to the vertical dimension ridge to cusp.

4. Any fin or flash on the denture will add to the vertical dimension.

5. The control of vertical dimension was equally good for injection and compression technics of processing dentures.

6. Excessive pressure during packing of the denture may increase the vertical dimension of the denture. The change in vertical dimension may vary with the type of investment used.

7. A testing device and technic for measuring vertical dimensional changes was developed which can be used to study this property for other materials and denture technics to a high degree of accuracy.