A comparison of posterior palatal seal creation in complete dentures by private practitioners and students at the University of Pretoria

Abstract

Aims: The aim of this study was to investigate the methods used by private practitioners and students to fabricate a posterior palatal seal in dentures and determine how many clinicians carry out this procedure themselves. Materials and methods: The laboratory slips, final impressions and final casts at jaw registration, try-in and finish stages of complete dentures of 50 student cases from the University of Pretoria and 10 cases from 5 private dental laboratories respectively were examined to determine the presence, position and dimensions of the post dam. Photographs and impressions were taken with polyvinyl siloxane impression material in cases where the post dam were marked and/or scribed. The impressions were sectioned with a scalpel and measurements were recorded with the aid of an Iwansson gauge and Carl Zeiss microscope. Depth and width was recorded at the midpalatal suture, right and left posterolateral, and right and left hamular notch areas of the scribed post dams. Results: In the private laboratory cases one of the 50 cases had the post dam marked at the secondary impression stage. In the student laboratory cases, 20% were marked at the secondary impression stage, 14% at the jaw registration and 12% at the try-in stages. Only 4% were scribed, all at the try-in stages. Measurements for post dam dimensions could only be made in 2 cases. Conclusions: Results of this study revealed a dismal lack of compliance and appreciation of the importance of the post dam by both students and experienced dental clinicians.