Distortion in dental soldering as affected by gap distance.

In identifying the criteria which influence soldering distortion, the results of this study indicate the following: 1. Linear distortion identified at the investment phase (a net increase in gap distance) is due to setting expansion of the plaster and soldering investment. 2. The linear distortion identified at the soldering phase (a net decrease in gap distance) occurs because of the contraction of the solder. 3. The rotational distortions measured were found to be minimal. 4. The use of a minimum gap distance, without contact, is desirable. 5. Adding solder results in a well-rounded, solid solder joint.