The Effect of Water Swaging on Stress and Strain in Dental-Wax Patterns

¹ Department of Operative Dentistry, School of Dentistry, University of Washington, Seattle, Washington

The effect of water waging on the stress and strain incorporated in dental-wax patterns constructed by three commonly used wax-manipulation techniques was studied. Sixty-six wax patterns were made. One-third of them were constructed by applying the wax to the die by each of the following methods: small increments, dry-annealed bulk, and flame-warmed bulk. One-half of the patterns formed by each method were water waged at 115° F., 600 psi for 15 seconds. Measurement of the distortion observed in each wax pattern was accomplished by incorporating a 31-gauge steel wire into the free end of each circular pattern and measuring under the microscope the distance between these wires before and after strain relaxation in a 110° F. water bath.

The following results were obtained. Ninety-eight per cent of all the patterns distorted in the strain-relaxation bath. No one method of applying wax to a die prior to waging was found to be highly superior to any other method, although flame-warmed bulk wax produced the greatest distortion. Swaged wax patterns distorted significantly less than unswaged patterns. Swaged patterns exhibited less variation in the degree and direction of their distortion.