How does adhesion differ from retention in dental materials?

Adhesion and retention, while related concepts in dental materials, refer to different mechanisms involved in how materials interact with each other and the dental surfaces. The correct choice highlights that retention is particularly relevant to materials that do not primarily rely on adhesives for their stability or hold.

Retention refers to the ability of a material to stay in place due to form, shape, or physical interlocking rather than adhesion. For example, a crown retained in place may rely on its anatomy and fit within a prepared tooth, where the mechanical features of the restoration ensure it does not dislodge without necessarily depending on adhesive properties.

While adhesion can indeed be important for certain types of bonding and can involve varying mechanisms such as chemical bonding or mechanical interlocking, the concept of retention specifically incorporates materials or constructs that function effectively without the need for adhesion. Thus, it appropriately emphasizes a different aspect of how materials can be maintained in a desired position or relationship within the oral environment.