Research related to pressures under dentures. On the effect of differences in impression pressure with special reference to unilateral mandibular free-end edentulousness.

The purpose of this paper is to investigate the difference of impression pressure under denture bases made by the pressure impression-taking method, which considers the resiliency of ligaments under abutment teeth and mucosa under dentures, and under those made by the non-pressure impression-taking method, and then analyzed its influence on the distribution of pressure curve produced by bite force with the case of unilateral mandibular free-end edentulousness. The findings were as follows: 1. As for the pressures under the dentures, dentures made by the pressure impression-taking method in all cases showed an apparent increase at the mesial part, while at the distal part, a decrease was detected in three out of five patients. 2. The pressure curve caused by bite force tended to rise sharply immediately before the application of maximum bite force. 3. Ratio of pressures resulting from the increased bite force tended to increase with dentures using the non-pressure impression-taking method, while dentures using the pressure impression-taking method showed a clear tendency to equalize toward 0.5, regardless of the values of the bite force.