Relationship between various functional impression techniques and different operators

The purpose of the present investigation was to determine the relationship between the reproducibility of soft tissue contours by three different functional impression techniques and four dentists for mandibular distal-extension removable partial dentures. The selected functional impression methods were Lejoyeux, Rouot and McLean techniques. A mucostatic impression technique was used for the control group. To compare and measure the degree of tissue displacement, a three-dimensional coordinate measuring system was used. The differences in vertical displacement of soft tissue among the operators were statistically determined for each impression technique used. Lejoyeux technique produced the least variation in tissue displacement followed respectively by McLean, mucostatic and Rouot methods.