Unit of Endodontology, Divisions of Restorative Dental Science, UCL Eastman Dental Institute, University College London, London, UK.
Department of Biological Sciences, Birkbeck University of London, London, UK.
Int Endod J. 2020 Jan;53(1):97-110. doi: 10.1111/iej.13200. Epub 2019 Aug 31.
To refine a FTIR protocol for detection of NaOCl-induced dentinal collagen changes using an ex vivo irrigation model, and to apply it to determine the collagen change within 0.5 mm of canal or root surfaces, with or without mature roots or periodontal involvement.
The root canals of extracted human roots were irrigated with control saline (n = 3) or 5% NaOCl (n = 3) and sectioned into transverse disks for FTIR analyses, 0.5 mm from both the canal lumen and root surface, before and after surface treatment with 17% EDTA. Amide I/phosphate and amide II/phosphate absorbance ratios were compared using the Wilcoxon sign rank test. Mature roots without periodontal involvement were irrigated with: saline (n = 7), 5% NaOCl (n = 7) or 5% NaOCl + 17% EDTA (n = 7); those with periodontal involvement (n = 7) or immature roots (n = 7) were irrigated with 5% NaOCl. Dentine disks were then prepared for FTIR analyses. The effects of irrigant/root maturity/periodontal involvement were analysed using linear mixed models.
FTIR analyses of the irrigated samples revealed a significant (P < 0.05) reduction in collagen bands near the canal lumen after NaOCl irrigation using surface EDTA-treated samples. Irrigation with the test solutions resulted in significant (P < 0.0001) dentinal collagen changes in the mature roots, whilst those in the immature roots were significantly (P < 0.05) greater compared with the mature roots with or without periodontal involvement; but there was no difference between the latter groups.
EDTA surface treatment of polished dentine surfaces enhanced FTIR detection of NaOCl-induced collagen changes. Both root maturity and irrigation protocol influenced the ability of NaOCl to alter dentinal collagen up to 0.5 mm from the canal lumen.
改进使用离体冲洗模型检测次氯酸钠诱导牙本质胶原变化的傅里叶变换红外光谱（FTIR）方案，并应用该方案确定距根管或根尖表面 0.5mm 范围内的胶原变化，无论是否有成熟根或牙周参与。
将离体人牙根的根管分别用对照生理盐水（n=3）或 5%次氯酸钠（n=3）冲洗，然后用 17%乙二胺四乙酸（EDTA）进行表面处理前后，将根管腔和根尖表面各 0.5mm 处切成横切片，进行 FTIR 分析。使用 Wilcoxon 符号秩检验比较酰胺 I/磷酸盐和酰胺 II/磷酸盐的吸光度比值。无牙周参与的成熟根分别用生理盐水（n=7）、5%次氯酸钠（n=7）或 5%次氯酸钠+17%EDTA（n=7）冲洗；有牙周参与的（n=7）或未成熟的根（n=7）用 5%次氯酸钠冲洗。然后制备牙本质圆盘进行 FTIR 分析。使用线性混合模型分析冲洗液/根成熟度/牙周参与的影响。
冲洗样本的 FTIR 分析显示，使用表面 EDTA 处理的样本，次氯酸钠冲洗后近根管腔的胶原带明显减少（P<0.05）。用测试溶液冲洗会导致成熟根的牙本质胶原发生明显变化（P<0.0001），而未成熟根的变化明显大于有或无牙周参与的成熟根（P<0.05）；但后两组之间无差异。
对抛光牙本质表面进行 EDTA 表面处理可增强 FTIR 检测次氯酸钠诱导的胶原变化。根的成熟度和冲洗方案都影响到次氯酸钠改变距根管腔 0.5mm 范围内牙本质胶原的能力。
