Time dependent deformation behavior of dentin

- The time dependent deformation of dentin was evaluated in coronal dentin using spherical indentation.
- There is a significant change in the time dependent deformation of dentin by location.
- A model accounting for spatial variations in composition and microstructure was developed to describe the time dependent deformation behavior of coronal dentin.
- Time Dependent Deformation Behavior of Dentin.

ObjectiveThe viscoelastic behavior of dentin and its ability to undergo time dependent deformation are considered to be important to oral functions and its capacity to resist fracture. There are spatial variations in the microstructure of dentin within the crown, which could be important to the viscous behavior. However, a spatially resolved description for the viscoelastic behavior of coronal dentin has not been reported.MethodsIn this investigation spherical indentations were made in three regions of coronal dentin including the outer, middle and inner regions. Power law relations were developed to quantitatively describe the stress-strain responses of the tissue.ResultsResults showed that the deformation behavior was strongly dependent on the composition (mineral to collagen ratio) and microstructure (tubule density), which contributed to an increase in the rate of viscous deformation with increasing proximity to the pulp.ConclusionsA model accounting for spatial variations in composition and microstructure was developed to describe the steady-state time dependent deformation behavior of coronal dentin, and a good agreement was found with the experimental results.