1. A zinc oxide-modified hydroxyapatite-based cement facilitated new crystalline-stoichiometric and amorphous apatite precipitation on dentine.
- Author
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Toledano, M., Pérez‐Álvarez, M. C., Aguilera, F. S., Osorio, E., Cabello, I., Toledano‐Osorio, M., and Osorio, R.
- Subjects
DENTIN ,HYDROXYAPATITE ,ZINC oxide ,CRYSTALLINITY ,DENTAL cements - Abstract
Aim To evaluate the remineralization ability of two endodontic sealer cements. Methodology Mid-coronal dentine surfaces were subjected to: (i) 37% phosphoric acid ( PA) or (ii) 0.5 mol L
−1 ethylenediaminetetraacetic acid ( EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide oxiapatite respectively. Samples were stored in simulated body fluid for 24 h or 21 days. Remineralization of the dentine surfaces were studied by Raman spectroscopy (mapping with K-means cluster and hierarchical cluster analysis) was undertaken. Nanoroughness and collagen fibril width measurements were performed with an atomic force microscopy. ANOVA and Student-Newman-Keuls test were performed (α=0.05). Results Phosphoric acid+oxiapatite promoted both the highest dentine mineralization ( P < 0.05) and crystallographic maturity at the dentine surface. Noncrystalline amorphous-like apatites were also formed. Dentine treated with PA+calcypatite attained the roughest surface ( P < 0.05) with minimal fibril width ( P < 0.05). Cross-linking of collagen only became greater in the group PA+oxiapatite after 21 days. The maximum relative mineral concentration and structure of collagen linked to the amide I and ratio amide III/ AGEs was obtained after using PA+calcypatite at 21-days time-point ( P < 0.05). EDTA produced a lower stoichiometric hydroxyapatite ( P < 0.05) with decreased maturity, at the expense of carbonate band widening, although it favoured the nucleation of carbonated calcium phosphate. Conclusions Dentine surfaces treated with PA+oxiapatite attained the highest dentine remineralization with both crystalline-stoichiometric and amorphous apatites, at 21 days. EDTA conditioning facilitated amorphous-bulk mineral precipitation. The amorphization was more intense after using oxiapatite and provided an ion-rich environment favouring in situ dentine remineralization. [ABSTRACT FROM AUTHOR]- Published
- 2017
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