Vertical displacement of distal-extension ridges by different impression techniques.

A study was conducted to compare tissue displacement resulting from different techniques and impression materials for distal-extension ridges. Impression techniques used were Applegate's functional fluid wax and a single-impression technique with mercaptan rubber. A mucostatic impression technique using irreversible hydrocolloid served as control. The results showed a statistically significant difference in tissue displacement between the casts made from the functional fluid wax technique and the single-impression technique with mercaptan rubber and the casts in the control group.