Cohesion in denture retention refers to the attractive forces between similar molecules within the thin saliva film present between the denture base and oral mucosa. These forces help maintain the saliva layer intact, contributing to the stability and retention of the denture. Unlike adhesion, which is the attraction between unlike molecules, cohesion ensures the saliva does not break apart easily under functional forces. This molecular attraction plays a crucial role in resisting dislodgement during mastication and speech. Understanding cohesion aids in optimizing denture fit and comfort for patients.

Reference: Prosthodontics, Robert F. Zarb, Edition 13.