Creep
The slow, time-dependent plastic deformation of a dental material under sustained load, particularly relevant in amalgam and polymer-based restorations.
Full Definition
Creep describes the progressive, permanent deformation that occurs in a material subjected to a constant stress over time, even when that stress is below the material's yield strength. In dental materials science, it is a critical performance parameter for amalgam, where high creep values are associated with marginal ditching and restoration failure. Editors should note that creep is distinct from elastic deformation, which is recoverable. It is typically reported as a percentage of dimensional change after a defined load duration. The ISO 24234 standard specifies maximum creep limits for dental amalgam.
Usage
Usage note: Do not confuse with 'flow' in the context of impression materials, which refers to a different rheological property. Creep is load-dependent and time-dependent simultaneously.
In Context
- "High creep values in amalgam restorations are correlated with marginal ditching at the cavosurface margin." — Peer-reviewed materials science journal
- "The investigator measured creep at 37 °C under a 36 MPa compressive load for seven days." — Laboratory testing protocol