Abstract
Dynamics of atmospheric pressure under the maxillary complete denture, and their relations with the denture retention influenced by the factors such as the denture seating force, the saliva viscosity and the postdamming, were investigated on the simulation models.
The following results were obtained.
1. The atmospheric pressure under the denture became higher than the external one by the denture insertion, and increased during the denture seating, and decreased by the removing force of denture and furthermore became lower than external one by continuous application of its force, and at all became equal to the external one when the denture separated from the basal seat.
2. Greater seating force brought about greater positive pressure and less negative pressure.
3. Higher viscosity of saliva and the postdamming brought about greater positive and negative pressures.
4. Both of greater seating force and higher viscosity of saliva brought about greater retentive force.
5. The postdamming was useful for the maxillary posterior border seal.
6. The atmospheric pressure under the denture base seems not to relate directly to the maxillary denture retention in the static condition but to reveal the status of peripheral seal.
