Relationship between various functional impression techniques and different operators

Area of Science:

• Dental Prosthodontics
• Biomaterials and Biomechanics

Background:

• Accurate soft tissue reproduction is critical for the stability and function of removable partial dentures.
• Functional impression techniques aim to capture the dynamic behavior of oral tissues under load, improving denture fit.

Purpose of the Study:

• To evaluate the reproducibility of soft tissue contours using three functional impression techniques (Lejoyeux, Rouot, McLean) and a mucostatic technique.
• To compare the degree of vertical soft tissue displacement among different impression methods and operators for mandibular distal-extension removable partial dentures.

Main Methods:

• Four dentists performed impressions using Lejoyeux, Rouot, McLean, and a mucostatic technique on the same subjects.
• A three-dimensional coordinate measuring system quantified the vertical displacement of soft tissues.
• Statistical analysis determined the differences in tissue displacement among operators for each technique.

Main Results:

• The Lejoyeux technique demonstrated the least variation in soft tissue displacement.
• The McLean technique showed slightly more variation than Lejoyeux, followed by the mucostatic technique.
• The Rouot technique resulted in the greatest variation in tissue displacement.

Conclusions:

• The Lejoyeux functional impression technique offers superior reproducibility for capturing mandibular soft tissue contours in distal-extension removable partial denture fabrication.
• Dentists' variations in technique significantly impact soft tissue displacement, highlighting the importance of standardized procedures.