@misc{10481/53639,
year = {2018},
month = {11},
url = {http://hdl.handle.net/10481/53639},
abstract = {Objective: The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. 
Material and Methods: Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (δ). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed. 
Results: After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface.  At both 24 h and 21 d, tan δ values at intertubular dentin treated with the four treatments performed similar.  At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups. 
Conclusions: Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan δ after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface.},
organization = {This  work  was  supported  by  the  Ministry  of  Economy  and  Competitiveness (MINECO) and European Regional Development Fund (FEDER) [MAT2017-85999-P MINECO/AEI/FEDER/UE]},
keywords = {Dentin},
keywords = {Fracture},
keywords = {Hydroxyapatite},
keywords = {Remineralization},
keywords = {Viscoelastic},
keywords = {Zinc},
title = {A zinc-doped endodontic cement facilitates functional mineralization and stress dissipation at the dentin surface.},
doi = {10.4317/medoral.22751},
author = {Pérez-Álvarez, Mayra C. and Osorio Ruiz, María Estrella and Lynch, Christopher D. and Toledano Osorio, Manuel and Toledano Pérez, Manuel and Osorio Ruiz, Raquel},
}