Department of Stomatology, Dental Materials Section, Faculty of Dentistry, University of Granada, Granada, Spain.
Biomaterials Department, University of La Havana, La Havana, Cuba.
Int Endod J. 2017 Dec;50 Suppl 2:e109-e119. doi: 10.1111/iej.12807. Epub 2017 Jul 31.
To evaluate the remineralization ability of two endodontic sealer cements.
Mid-coronal dentine surfaces were subjected to: (i) 37% phosphoric acid (PA) or (ii) 0.5 mol L 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).
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.
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.
评估两种根管封闭剂的再矿化能力。
将中段牙本质表面用 37%磷酸（PA）或 0.5mol/L 乙二胺四乙酸（EDTA）预处理，然后分别应用两种含氢氧化钠（钙磷灰石）或氧化锌氧磷灰石的实验性羟基磷灰石基水泥。将样本在模拟体液中储存 24 小时或 21 天。通过拉曼光谱（用 K-均值聚类和层次聚类分析进行映射）研究牙本质表面的再矿化情况。用原子力显微镜进行纳米粗糙度和胶原纤维宽度测量。采用方差分析和 Student-Newman-Keuls 检验（α=0.05）。
磷酸+氧磷灰石促进了牙本质表面的最高矿化（P<0.05）和结晶成熟度。还形成了非晶态类似磷灰石。经 PA+钙磷灰石处理的牙本质表面最粗糙（P<0.05），胶原纤维宽度最小（P<0.05）。只有在 21 天后，PA+氧磷灰石组的胶原交联才会增加。用 PA+钙磷灰石处理 21 天后，获得了最大的相对矿化浓度和与酰胺 I 相连的胶原结构以及酰胺 III/AGEs 比值（P<0.05）。EDTA 产生了较低的化学计量羟基磷灰石（P<0.05），结晶成熟度降低，代价是碳酸盐带变宽，尽管它有利于碳酸磷灰石的成核。
在 21 天时，用 PA+氧磷灰石处理的牙本质表面获得了最高的牙本质再矿化，既有结晶态的化学计量比磷灰石，也有无定形磷灰石。EDTA 处理有利于无定形大块矿化沉淀。在用氧磷灰石处理后，非晶化更为剧烈，提供了一个富含离子的环境，有利于原位牙本质再矿化。
