Strength Properties of Waxes at Various Temperatures and Their Practical Application

¹ University of Michigan, School of Dentistry, Ann Arbor, Michigan

The strength properties in compression of elastic modulus, proportional limit, and ultimate strength of some representative natural and dental waxes were determined at temperatures from 23° to 40°C. The strength properties of natural waxes at room temperature were in the decreasing order of carnauba, paraffin, and beeswax, and those of the dental inlay waxes were higher than a dental casting wax. The strength properties decreased with increasing temperatures although the order of the waxes at 40°C. was not always the same as at 23°C.

An example of the importance of the strength properties was presented by relating the dimensions of a simplified MOD wax pattern to the selection of wax for various portions of the pattern. The variations in dimensions of the wax pattern under stress during investing may be compensated for by selection of waxes with the proper elastic moduli.