Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru SP, Brazil.
Department of Physics, Faculty of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
Int Endod J. 2018 Jan;51 Suppl 1:e42-e54. doi: 10.1111/iej.12764. Epub 2017 Apr 10.
To investigate the effects of several decalcifying agents alone and in combination with sodium hypochlorite (NaOCl) on the organic and inorganic components of dentine using attenuated total reflectance in Fourier transform infrared spectroscopy (ATR-FTIR).
Dentine slices from bovine teeth were submitted to (n = 5) the following: 0.9% saline, 9% and 18% etidronic acid (HEDP), 5% and 10% tetrasodium EDTA (EDTANa ), 17% trisodium EDTA (EDTAHNa ), and 0.5% and 2.0% peracetic acid (PAA) for 0.5-10 min; and to the combinations: G1 - mixture 5% NaOCl + 18% HEDP (5 and 10 min); G2 - mixture 5% NaOCl + 10% EDTANa (5 and 10 min); G2 - 2.5% NaOCl (5 min) + 17% EDTAHNa (1 min); G3 - 2.5% NaOCl (5 min) + 0.5% PAA (1 min); G4 - 2.5% NaOCl (5 min) + 9% HEDP (5 min). Specimens of G2, G3 and G4 received final flushes with 2.5% NaOCl for 0.5-10 min. Amide III/phosphate and carbonate/phosphate ratios of the spectra collected from the dentine specimens before and after immersion in the solutions were determined. Data were submitted to one-way repeated measures and one-way anova.
For the same decalcifying agent, the higher the concentration and immersion time the greater the removal of phosphate, exposure of collagen matrix and consequently the increases in amide III/phosphate ratio. However, significant differences were found only between the two concentrations of PAA (P < 0.05). PAA caused greater increases in this ratio, followed by EDTAHNa , EDTANa and HEDP, and this order was retained in the combinations with NaOCl. This ratio was significantly reduced in G1 (P < 0.05) and not altered in G2 (P > 0.05). Due to collagen degradation, the amide III/phosphate ratio reduced significantly after the use of NaOCl in G3, G4 and G5 (P < 0.05). NaOCl required approximately 0.5 s to deproteinate the collagen matrix exposed after phosphate removal by EDTAHNa and PAA. The carbonate of dentine was removed more rapidly than phosphate by all decalcifying agents alone and in G3, G4 and G5. In the combinations with NaOCl, the last irrigant used defined the dentine amide III/phosphate and carbonate/phosphate ratios.
HEDP and EDTANa caused minor whilst EDTAHNa and PAA caused greater demineralization of dentine; both effects were time and concentration dependent. NaOCl degraded the dentine organic matrix more rapidly when it was exposed. Combinations of NaOCl and decalcifying agents can be used to create dentine surfaces with varying compositions for interaction with endodontic sealers.
使用衰减全反射傅里叶变换红外光谱法（ATR-FTIR）研究几种单独和组合使用次氯酸钠（NaOCl）的脱钙剂对牙本质的有机和无机成分的影响。
将牛牙的牙本质切片分别放入（n=5）以下溶液中：0.9%生理盐水、9%和 18%依替膦酸（HEDP）、5%和 10%四钠乙二胺四乙酸（EDTANa）、17%三钠乙二胺四乙酸（EDTAHNa）和 0.5%和 2.0%过氧乙酸（PAA），浸泡 0.5-10 分钟；以及以下组合：G1-混合物 5% NaOCl+18% HEDP（5 和 10 分钟）；G2-混合物 5% NaOCl+10% EDTANa（5 和 10 分钟）；G2-2.5% NaOCl（5 分钟）+17% EDTAHNa（1 分钟）；G3-2.5% NaOCl（5 分钟）+0.5% PAA（1 分钟）；G4-2.5% NaOCl（5 分钟）+9% HEDP（5 分钟）。G2、G3 和 G4 的标本在最后冲洗时使用 2.5% NaOCl，浸泡 0.5-10 分钟。用溶液浸泡前后牙本质标本的酰胺 III/磷酸盐和碳酸盐/磷酸盐比值进行测定。数据采用单向重复测量和单因素方差分析。
对于相同的脱钙剂，浓度越高，浸泡时间越长，磷酸盐去除越多，胶原基质暴露越多，酰胺 III/磷酸盐比值增加越大。然而，只有在 PAA 的两种浓度之间（P<0.05）才发现显著差异。PAA 引起的酰胺 III/磷酸盐比值增加最大，其次是 EDTAHNa、EDTANa 和 HEDP，这一顺序在与 NaOCl 的组合中保持不变。G1 中的该比值显著降低（P<0.05），而 G2 中未发生变化（P>0.05）。由于胶原降解，G3、G4 和 G5 中使用 NaOCl 后酰胺 III/磷酸盐比值显著降低（P<0.05）。NaOCl 只需大约 0.5 秒即可去除 EDTAHNa 和 PAA 去除磷酸盐后暴露的胶原基质中的蛋白质。所有脱钙剂单独使用和在 G3、G4 和 G5 中均能更快速地去除牙本质中的碳酸盐，而不是磷酸盐。在与 NaOCl 的组合中，最后使用的冲洗剂决定了牙本质的酰胺 III/磷酸盐和碳酸盐/磷酸盐比值。
HEDP 和 EDTANa 引起的脱矿作用较小，而 EDTAHNa 和 PAA 引起的脱矿作用较大；这两种效果都与时间和浓度有关。暴露时，NaOCl 会更快地降解牙本质有机基质。NaOCl 和脱钙剂的组合可用于为牙本质表面创造不同的成分，以与根管封闭剂相互作用。
