osseointegration

This term is a highly specialized medical and dental descriptor used primarily in clinical settings, orthopedic surgery, and biomaterials research. It describes a biological process rather than a simple mechanical fit, implying a seamless fusion where the bone grows directly into the implant surface without an intervening layer of fibrous tissue.

As a technical term for a specific biological phenomenon, it is treated as an uncountable noun. It refers to the state or process of integration, and therefore does not typically take a plural form in professional medical literature.