Interface Degradation

A progressive reduction in functional performance at a component or subsystem interface caused by mechanical, chemical, thermal or environmental interactions that alter contact geometry, material properties or interfacial films, resulting in degraded load transfer, signal integrity, sealing, or other interface‑level functions without necessarily implying instantaneous catastrophic failure.

Progressive deterioration of the chemical, mechanical or barrier properties at the bond interface between a restorative material and a substrate (tooth structure, cement, implant surface or another restorative), manifested by reduced adhesion, gap formation, microleakage, or altered mechanical coupling.