Original Item ID
To develop a protocol for assessment of the bulk viscoelastic behavior of dentin extracellular matrix (ECM), and to assess relationships between induced collagen cross-linking and viscoelasticity of the dentin ECM.
Dentin ECM was treated with agents to induce exogenous collagen cross-linking: proanthocyanidins (PACs) from Vitis vinifera – VVe, PACs from Pinus massoniana - PMe, glutaraldehyde – (GA), or kept untreated (control). A dynamic mechanical strain sweep method was carried out in a 3-point bending submersion clamp at treatment; after protein destabilization with 4 M urea and after 7-day, 6-month, and 12-month incubation in simulated body fluid. Tan δ, storage (E’), loss (E”), and complex moduli (E*) were calculated and data were statistically analyzed using two-way ANOVA and post-hoc tests (α = 0.05). Chemical analysis of dentin ECM before and after protein destabilization was assessed with ATR-FTIR spectroscopy.
Significant interactions between study factors (treatment vs. time points, p < 0.001) were found for all viscoelastic parameters. Despite a significant decrease in all moduli after destabilization, PAC-treated dentin remained statistically higher than control (p < 0.001), indicating permanent mechanical enhancement after biomodification. Covalently crosslinked, GA-treated dentin was unaffected by destabilization (p = 0.873) and showed the lowest damping capacity (tan δ) at all time points (p < 0.001). After 12 months, the damping capacity of PMe and VVe groups decreased significantly. Changes in all amide IR resonances revealed a partial chemical reversal of PAC-mediated biomodification.
Viscoelastic measurements and IR spectroscopy aid in elucidating the role of inter-molecular collagen cross-linking in the mechanical behavior of dentin ECM.
Alania, Yvette; Cavalcante dos Reis, Mariana; Nam, Joo-Won; Phansalkar, Rasika S.; McAlpine, James; Chen, Shao-Nong; Pauli, Guido F.; and Bedran-Russo, Ana K., "A Dynamic Mechanical Method to Assess Bulk Viscoelastic Behavior of the Dentin Extracellular Matrix" (2020). School of Dentistry Faculty Research and Publications. 381.
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