Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
Int Endod J. 2024 Apr;57(4):477-489. doi: 10.1111/iej.14027. Epub 2024 Jan 19.
Endodontic irrigants may affect the mechanical and chemical properties of dentine. This study evaluated the effects of various final irrigation protocols including the use of chitosan nanoparticle (CSnp) and cross-linking with genipin on the (1) mechanical and (2) chemical properties of dentine against enzymatic degradation.
CSnp was synthesized and characterized considering physiochemical parameters and stability. The root canals of 90 single-rooted teeth were prepared and irrigated with NaOCl. Dentine discs were obtained and divided into groups according to the following irrigation protocols: Group NaOCl+EDTA, Group NaOCl+CSnp, Group NaOCl+EDTA+CSnp, Group NaOCl+CSnp+Genipin, Group NaOCl+EDTA+CSnp+Genipin and Group distilled water. (1) Mechanical changes were determined by microhardness analysis using Vickers-tester. (2) Chemical changes were determined by evaluating molecular and elemental compositions of dentine using Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscope (SEM)/energy dispersive X-ray spectroscopy (EDS) analysis, respectively. All analyses were repeated after the discs were kept in collagenase for 24 h. Data were analysed with repeated measures analysis of variance and Bonferroni correction for microhardness analysis, and Kruskal-Wallis and Wilcoxon tests for FTIR and SEM/EDS analyses (p = .05).
(1) Collagenase application did not have a negative effect on microhardness only in Group NaOCl+EDTA+CSnp+Genipin when compared with the post-irrigation values (p > .05). Post-collagenase microhardness of Group NaOCl+EDTA+CSnp and Group NaOCl+CSnp+Genipin was similar to the initial microhardness (p > .05). (2) After collagenase, Amide III/ ratio presented no change in Group NaOCl+EDTA+CSnp, Group NaOCl+CSnp+Genipin and Group NaOCl+EDTA+CSnp+Genipin (p > .05), while decreased in other groups (p < .05). Collagenase did not affect / ratio in the groups (p > .05). There were no changes in the groups in terms of elemental level before and after collagenase application (p > .05).
CSnp and genipin positively affected the microhardness and molecular composition of dentine. This effect was more pronounced when CSnp was used after EDTA.
牙髓冲洗剂可能会影响牙本质的机械和化学性质。本研究评估了各种最终冲洗方案的效果，包括使用壳聚糖纳米粒子（CSnp）和与京尼平交联对（1）机械性能和（2）抗酶降解的牙本质的化学性质的影响。
考虑到物理化学参数和稳定性，合成并表征了 CSnp。将 90 颗单根牙的根管进行预备并冲洗次氯酸钠。获得牙本质片，并根据以下冲洗方案将其分为不同的组：组 NaOCl+EDTA、组 NaOCl+CSnp、组 NaOCl+EDTA+CSnp、组 NaOCl+CSnp+京尼平、组 NaOCl+EDTA+CSnp+京尼平和组蒸馏水。（1）通过使用维氏硬度计进行微硬度分析来确定机械变化。（2）通过使用傅里叶变换红外光谱（FTIR）分析评估牙本质的分子和元素组成，以及扫描电子显微镜（SEM）/能量色散 X 射线光谱（EDS）分析来分别确定化学变化。将牙本质片在胶原酶中保持 24 小时后重复所有分析。使用重复测量方差分析和 Bonferroni 校正对微硬度分析进行数据分析，使用 Kruskal-Wallis 和 Wilcoxon 检验对 FTIR 和 SEM/EDS 分析进行数据分析（p=0.05）。
（1）与冲洗后的数值相比，仅在 NaOCl+EDTA+CSnp+京尼平组中，胶原酶的应用对微硬度没有负面影响（p＞0.05）。NaOCl+EDTA+CSnp 组和 NaOCl+CSnp+京尼平组的胶原酶后微硬度与初始微硬度相似（p＞0.05）。（2）在胶原酶作用后，NaOCl+EDTA+CSnp、NaOCl+CSnp+京尼平和 NaOCl+EDTA+CSnp+京尼平组的酰胺 III/ 比值没有变化（p＞0.05），而其他组则下降（p＜0.05）。胶原酶对各组的 / 比值没有影响（p＞0.05）。胶原酶作用前后各组的元素水平没有变化（p＞0.05）。
CSnp 和京尼平对牙本质的微硬度和分子组成有积极影响。当 EDTA 后使用 CSnp 时，效果更为明显。
