Measurement of retentive force
The palatal plate was placed in the mouth after applying the substance to its inner surface. Then, a constant load of 25 N was applied for 10 s in the direction of the occlusal plane using the device for pressure welding. The palatal plate was then towed at an angle of 60° to Camper’s plane at a rate of 1 N/s to measure the retentive force. The maximum retentive force until the palatal plate detached from the palatal mucosa was measured. After measurement, the palatal plate was again fitted, and 25 N pressure was applied using the device for pressure welding. The measurements started when the palatal plate was fitted and were taken every 10 min for 30 min. They were repeated four times at each 10-min time point, with the first time being excluded and the average of the second to fourth times taken as the measured retentive force at that time point. In addition, averages were calculated for each time point for the 10 study participants (Fig. 