A characterization of the mechanical behavior of resin-infiltrated dentin using nanoscopic Dynamic Mechanical Analysis

作者：Ryou Heonjune; Pashley David H; Tay Franklin R; Arola Dwayne^*

来源：Dental Materials, 2013, 29(7): 719-728.

DOI：10.1016/j.dental.2013.03.022

• Dynamic Mechanical Analysis
• Elastic modulus
• Hybrid layer
• Nanoindentation

This study explored the spatial variations in mechanical behavior of resin-infiltrated dentin using nanoscopic Dynamic Mechanical Analysis (DMA). %26lt;br%26gt;Objective. The objectives were to: (1) evaluate the mechanical behavior of resin-infiltrated dentin using a scanning-based approach to nanoindentation, (2) identify contributions of the collagen matrix to time-dependent deformation of the hybrid layer, and (3) assess the importance of specimen hydration on the nanoDMA response. %26lt;br%26gt;Methods. Specimens of completely demineralized dentin infiltrated with commercial resin adhesive and control samples of resin adhesive were evaluated using a nanoindenter in scanning mode. The load and displacement responses were used to perform DMA and to estimate the complex (E*), storage (E%26apos;) and loss (E %26apos;%26apos;) moduli over selected regions of evaluation. The importance of hydration on the mechanical behavior was also examined from a comparison of responses in the hydrated and dehydrated conditions. %26lt;br%26gt;Results. In the hydrated state the apparent complex, storage and loss moduli for the resininfiltrated dentin samples were 3.5 +/- 0.3 GPa, 3.4 +/- 0.2 GPa and 0.9 +/- 0.3 GPa, respectively. Those values for the resin adhesive control were 2.7 +/- 0.3 GPa, 2.7 +/- 0.3 GPa and 0.2 +/- 0.02 GPa, respectively. Viscoelastic deformation of the resin-infiltrated collagen exceeded that occurring in regions of uniform resin adhesive. Though dehydration resulted in a significant increase in both the complex and storage moduli of the macro hybrid layer, the largest changes occurred to the resin adhesive. %26lt;br%26gt;Significance. The microstructure and hydration play critical roles on the mechanical behavior of the hybrid layer and nanoDMA provides a potent measurement tool for identifying the spatial variations.

• 出版日期2013-7