Savaris Julia Menezes, Dotto Maria Eduarda Paz, Garcia Lucas da Fonseca Roberti, Silva Emmanuel João Nogueira Leal da, Henriques Bruno Alexandre Pacheco de Castro, Teixeira Cleonice da Silveira, Bortoluzzi Eduardo Antunes
Universidade Federal de Santa Catarina - UFSC, Postgraduate Program in Dentistry, Florianópolis, SC, Brazil.
Universidade Estadual do Rio de Janeiro - UERJ, School of Dentistry, Department of Endodontics, Rio de Janeiro, RJ, Brazil.
Braz Oral Res. 2024 Dec 9;38:e072. doi: 10.1590/1807-3107bor-2024.vol38.0072. eCollection 2024.
This study compared the effects of different final irrigation protocols on the mechanical properties and structural integrity of root dentine. One-hundred eight teeth were instrumented and irrigated with sodium hypochlorite (NaOCl) using conventional irrigation (CI). Teeth were distributed into four groups based on final irrigation protocols: Control Group (CG): 17%EDTA/CI + H2O; G1: 2.5%NaOCl/Passive Ultrasonic Irrigation (PUI) + EDTA/PUI + NaOCl/PUI (60s each); G2: EDTA/PUI + NaOCl/PUI (30s each); G3: EDTA/PUI + NaOCl/PUI + H2O/PUI + CHX/PUI (30s each). Four tests were conducted: three-point flexural strength test, Scanning Electron Microscopy analysis, microhardness assessment, and the push-out bond strength (POBS) of the filling material to the root dentine. Data were analyzed using ANOVA and Tukey tests (Flexural strength), and Student t-test (Microhardness). Erosion scores and POBS were analyzed by Kruskal-Wallis and Dunn tests (α = 0.05). Results indicated no significant differences in flexural strength (p > 0.05) among groups. CG exhibited the lowest erosion scores in the cervical third. In the middle third, CG had lower scores than G1 and G2, while in the apical third, CG had lower scores than G1 (p < 0.05). Microhardness values decreased following the protocols (p < 0.05), except for the CG (p > 0.05). G2 displayed higher POBS values in the middle and apical thirds (p < 0.05). The protocols did not significantly influence the flexural strength of root dentine. However, they did affect microhardness and promoted greater erosion. The best results for POBS were observed when the final irrigation involved the sequential use of EDTA and NaOCl employing PUI for 30 seconds in each solution.
本研究比较了不同最终冲洗方案对牙根牙本质力学性能和结构完整性的影响。108颗牙齿进行了根管预备，并用次氯酸钠（NaOCl）采用传统冲洗（CI）方法进行冲洗。根据最终冲洗方案将牙齿分为四组：对照组（CG）：17%乙二胺四乙酸（EDTA）/CI + 水；G1组：2.5%NaOCl/被动超声冲洗（PUI）+ EDTA/PUI + NaOCl/PUI（各60秒）；G2组：EDTA/PUI + NaOCl/PUI（各30秒）；G3组：EDTA/PUI + NaOCl/PUI + 水/PUI + 洗必泰（CHX）/PUI（各30秒）。进行了四项测试：三点弯曲强度测试、扫描电子显微镜分析、显微硬度评估以及充填材料与牙根牙本质之间的推出粘结强度（POBS）测试。数据采用方差分析（ANOVA）和Tukey检验（弯曲强度）以及学生t检验（显微硬度）进行分析。侵蚀评分和POBS采用Kruskal-Wallis检验和Dunn检验进行分析（α = 0.05）。结果表明，各组之间的弯曲强度无显著差异（p > 0.05）。CG组在颈部三分之一处的侵蚀评分最低。在中部三分之一处，CG组的评分低于G1组和G2组，而在根尖三分之一处，CG组的评分低于G1组（p < 0.05）。除CG组外（p > 0.05），按照冲洗方案处理后显微硬度值降低（p < 0.05）。G2组在中部和根尖三分之一处显示出更高的POBS值（p < 0.05）。冲洗方案对牙根牙本质的弯曲强度没有显著影响。然而，它们确实影响了显微硬度并加剧了侵蚀。当最终冲洗采用在每种溶液中使用PUI依次冲洗30秒的EDTA和NaOCl时，观察到POBS的最佳结果。
