Analysis of the posterior palatal seal and the palatal form as related to the retention of complete dentures.

Dislodging forces were applied at three different locations--anterior, posterior, middle--on acrylic resin bases of uniform thickness. The influence of different posterior palatal seals and the form of the palate were evaluated. A Pearson statistical correlation analysis was performed to correlate these factors. The findings were as follows: 1. The anterior attachment needed for greatest amount of force to dislodge the base; the posterior attachment needed the least. 2. The middle attachment showed more variability of the forces needed to dislodge the bases. It was influenced by the form of the palate, the type of posterior palatal seal, and the weight of the bases. 3. The middle location is the most reliable region for testing the retention of complete dentures. 4. The form of the palate has direct influence on the retention of complete dentures and will aid in the selection of the type of posterior palatal seal needed.