A comparison of the retention of complete denture bases having different types of posterior palatal seal with different palatal forms


Background: The most common problem associated with the lack of retention of maxillary complete denture is faultyposterior palatal seal pps. The methods for achieving a pps include arbitrarily scraping the cast, selective pressuretechnique, and the physiologic impression technique.Material and Method: In this study forces required to dislodge a maxillary complete denture bases were comparedfor different types of posterior palatal seals (PPS) with different palatal forms by using a specially designed straingauge force tranducer and strain measuring device. Nine male and female subjects are selected with age range55-70 years. These patients with different palatal forms according to House's classification of palatal forms: Class I flat,Class II intermediate and Class III high. Using different impression technique the first ordinary impression with Zincoxideeugenol and scraping the cast for pps, the second physiological impression by using korecta wax No.4.Result: The results show very highly significant difference, between the different designs of pps and physiologicalimpression for each group.Conclusion: The physiological impression of pps give better retention because no over compression of tissues (withinthe physiological limit) and concluded that the form of palate has direct influence on the retention of completedentures and will aid in the selection of type of posterior palatal seal needed