Department of Restorative Dentistry, Dental Materials and Endodontics, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
School of Biosciences, University of Birmingham, Birmingham, UK.
Int Endod J. 2021 Aug;54(8):1369-1382. doi: 10.1111/iej.13522. Epub 2021 Apr 12.
To assess the chemical and microstructural characteristics of dentine after the use of two irrigation protocols and correlate this with the antimicrobial properties of hydraulic calcium silicate cement (HCSC) sealers and changes to the dentine structure/chemistry after sealer placement.
Two irrigation protocols - Protocol A using 2% NaOCl used 5 mL/5 min and Protocol B with 2% NaOCl (5 mL/5 min) followed by 17% EDTA (5 mL/3 min) - were used to prepare dentine. The chemical and microstructural changes following irrigation were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy (n = 5) on dentine obtained from the mid-root and coronal parts of extracted human teeth. Four sealers (AH Plus, BioRoot, MTA Fillapex, TotalFill) were characterized by SEM/EDS (n = 3). The ability of the sealers to eradicate intratubular Enterococcus faecalis biofilms was assessed by live/dead dye and confocal laser scanning microscopy to measure the percentage of living cells. The effect of combined irrigation and root filling on dentine was assessed by SEM and EDS analysis (n = 5). Statistical analysis was undertaken using one-way anova and a number of post hoc tests to detect intergroup differences. The F-test was used for comparison of variances in the microbiology testing.
The use of NaOCl alone left the smear layer intact, with traces of chlorine remaining on dentine. The use of BioRoot sealer restored the calcium levels of dentine which had been depleted by the irrigation with EDTA. BioRoot exhibited antimicrobial properties against intratubular bacteria even in the presence of smear layer (Protocol A). Smear layer removal improved the bactericidal effect of all sealers and Ca leaching. The use of a chelating agent was important for the intratubular sealer penetration for AH Plus but not the other sealers.
The removal of smear layer was necessary for penetration of AH Plus into the dentinal tubules. BioRoot was a more effective sealer in reducing the bacterial load in the dentinal tubules than the other materials tested and the presence of smear layer did not affect its activity.
评估两种冲洗方案后牙本质的化学和微观结构特征，并将其与液压硅酸钙水泥（HCSC）密封剂的抗菌性能以及密封剂放置后牙本质结构/化学的变化相关联。
使用两种冲洗方案-方案 A 用 2%次氯酸钠冲洗 5 分钟，方案 B 先用 2%次氯酸钠冲洗 5 分钟，然后用 17% EDTA 冲洗 3 分钟-来制备牙本质。通过扫描电子显微镜（SEM）、能量色散光谱（EDS）和傅里叶变换红外（FT-IR）光谱评估冲洗后牙本质的化学和微观结构变化（n=5），牙本质取自离体人牙的中根和冠部。通过 SEM/EDS 对 4 种密封剂（AH Plus、BioRoot、MTA Fillapex、TotalFill）进行了表征（n=3）。通过活/死染料和共聚焦激光扫描显微镜评估密封剂根除管内粪肠球菌生物膜的能力，以测量活细胞的百分比。通过 SEM 和 EDS 分析评估联合冲洗和根管充填对牙本质的影响（n=5）。使用单向方差分析和多项事后检验进行统计分析，以检测组间差异。使用 F 检验比较微生物学测试中的方差。
单独使用次氯酸钠会使玷污层完整，牙本质上仍有氯的痕迹。使用 BioRoot 密封剂可恢复因 EDTA 冲洗而耗尽的牙本质钙水平。即使存在玷污层，BioRoot 也对管内细菌具有抗菌性能（方案 A）。玷污层的去除提高了所有密封剂和 Ca 浸出的杀菌效果。螯合剂的使用对于 AH Plus 进入牙本质小管内的渗透是重要的，但对于其他密封剂则不然。
玷污层的去除对于 AH Plus 进入牙本质小管内的渗透是必要的。与测试的其他材料相比，BioRoot 是一种更有效的密封剂，可以减少牙本质小管内的细菌负荷，并且存在玷污层不会影响其活性。
