Abstract
Retention and stability are essential for the success of complete denture treatment. Previously, evaluation of complete denture retention forces required large equipment, and it was difficult to perform chair-side evaluation. Therefore, we developed a compact device that can measure the retention forces. The purpose of this paper was to determine the reproducibility of this newly-developed retention measuring system using various oral moisturizers. The newly-developed retention measuring system consisted of a metal spatula and a strain gauge. Palatal plates were made for 14 healthy dentate individuals. Three oral moisturizers, namely artificial saliva, and liquid-type and gel-type moisturizers, were used between the palate and palatal plates. The palatal plate was pressed on the palate for 10 seconds and then pulled at a certain speed. Retention forces were recorded when the palatal plate detached. The retention force of the palatal plate increased in the following order： artificial saliva, liquid moisturizer and gel moisturizer. Retention force varied from 0.9 to 17.7 N. The standard deviation of measured values with different mediating fluids for individual subjects was relatively small, indicating little variation. In addition, three-way ANOVA showed significant differences when comparing between subjects and when comparing subjects and mediating fluid type (p＜0.05), however repetition was not significant (p＝0.346). These findings demonstrate that the newly-developed retention force measuring device can measure various retention forces, and the device has good reproducibility when used intraorally. This suggests that the device could be used for chair-side measurement.
