Division of Endodontics, University at Buffalo, School of Dental Medicine, Buffalo, NY, USA.
Dental Materials Research Laboratory, University at Buffalo, School of Dental Medicine, Buffalo, NY, USA.
Int Endod J. 2020 Oct;53(10):1438-1445. doi: 10.1111/iej.13354. Epub 2020 Jul 30.
To evaluate the effects of the prolonged use of various irrigant solutions used during regenerative endodontic procedures on the physical and chemical structure of root canal dentine in extracted human teeth.
Sixtyroot dentine samples from extracted, single-rooted, human teeth were assigned to 10 groups. Eight groups were irrigated with 1.5% NaOCl for 5 min, followed by 3%, 10%, 17% EDTA or 10% citric acid (CA) for 5 or 10 min. One group received only NaOCl irrigation, and samples with only distilled water irrigation were used as a control group. The changes in microhardness and flexural strength were determined using Vickers and 3-point flexural tester, respectively. Molecular and elemental compositions were recorded using FTIR and EDS spectroscopy. Data were analysed using one-way anova, Kruskal-Wallis and Mann-Whitney U tests.
The application of 1.5% NaOCl for 5 min did not affect the mineral content or microhardness of dentine (P > 0.05). However, it significantly decreased the dentine collagen peak values (P < 0.05), which was similar to the control group after the use of chelating agents (EDTA and 10% of CA) (P > 0.05). The effect of EDTA on the inorganic content was not concentration and time dependent (P > 0.05). CA resulted in a significantly greater reduction in the inorganic contents compared with the control and EDTA groups (P < 0.05). Regardless of the time, EDTA and CA significantly decreased dentine microhardness compared to the control (P < 0.05) with the greatest reduction in the CA groups (P < 0.05). NaOCl alone was associated with the lowest flexural strength, while none of the other irrigation regimens significantly decreased the flexural strength compared to the control group (P> 0.05).
Use of 1.5% NaOCl for 5 min decreased the collagen content of samples of human dentine from extracted teeth while EDTA and 10% citric acid mostly affected the inorganic content and microhardness of dentine surfaces. None of the irrigant solutions significantly decreased the mechanical properties of the entire dentine specimen.
评估再生牙髓治疗过程中使用的各种冲洗液在延长使用时间后对人离体牙根管牙本质理化结构的影响。
将 60 个人离体单根牙的牙本质样本分为 10 组。8 组样本用 1.5%次氯酸钠冲洗 5 分钟，然后用 3%、10%、17%乙二胺四乙酸（EDTA）或 10%柠檬酸（CA）分别冲洗 5 分钟或 10 分钟。一组仅接受次氯酸钠冲洗，而仅用蒸馏水冲洗的样本作为对照组。使用维氏硬度计和三点弯曲测试仪分别测定微硬度和弯曲强度的变化。使用傅里叶变换红外光谱仪（FTIR）和能谱仪（EDS）记录分子和元素组成。采用单因素方差分析、Kruskal-Wallis 和 Mann-Whitney U 检验进行数据分析。
5 分钟 1.5%次氯酸钠的应用并未影响牙本质的矿物质含量或微硬度（P＞0.05）。然而，它显著降低了牙本质胶原峰值（P＜0.05），与螯合剂（EDTA 和 10%CA）使用后的对照组相似（P＞0.05）。EDTA 对无机含量的影响与浓度和时间无关（P＞0.05）。CA 导致无机含量的降低明显大于对照组和 EDTA 组（P＜0.05）。无论时间如何，EDTA 和 CA 均显著降低牙本质微硬度，与对照组相比（P＜0.05），以 CA 组降低幅度最大（P＜0.05）。单独使用次氯酸钠与最低的弯曲强度相关，而其他冲洗方案与对照组相比均未显著降低弯曲强度（P＞0.05）。
5 分钟 1.5%次氯酸钠的使用降低了人离体牙牙本质样本的胶原含量，而 EDTA 和 10%柠檬酸主要影响牙本质表面的无机含量和微硬度。没有一种冲洗液显著降低整个牙本质标本的机械性能。
