[The effect of postpalatal seal on the retention of a full upper denture].

The retention of a full upper denture is seriously affected by the border seal and especially by a correct and strong postpalatal seal, which occurred before the receiving of the final impression. In this article we describe the effects of a correct and strong pospalatal seal on the function of a full upper denture, as well as the procedure that should be followed in order to achieve a correct posterior palatal seal.