Retention, on the other hand, is the principle that describes the ability for the dentures to be held in place and prevented from moving up or down in the opposite course of insertion. The more superior the topographical imitation between the interior surface of the base of the denture to the surface of the underlying mucosa, the better the retention will be. With detachable partial dentures, retention is a function of how well the clasps hold. The idea of retention is surface tension which is increased with simple suction and or merely friction. Each of these elements will aid in maintaining the denture base from breach close contact with the mucosal surface. It is essential to note that the most vital aspect in the retentive design of a full maxillary denture is an absolute and overall border seal. A complete peripheral seal between base and mucosa is necessary in order to achieve ample suction.

Implant technology has vastly improved patient experience with denture use. It has done so by increasing stability and saving bone mass from wearing away. Moreover, advances in implants have also helped with the aspect of retention. Now, rather than merely placing the implants to serve as a block against dentures pushing on the alveolar bone, small retentive clasps can be fixed onto the implants which will then snap into a adapted denture base to allow for vastly improved retention capabilities.

These two concepts are the principles that explain how well dentures can be held in place from moving vertically with better imitation of interior surfaces along the denture base and advancements in implant technology for better stability and retention.