目的: 评估常温流动牙胶封闭剂单尖充填法对弯曲根管的封闭效果。方法: (1) 3D打印轻、中、重度弯曲根管模型各20例, 分别采用热垂直加压技术(warm vertical compaction, 以AH-Plus为封闭剂, 以下称WVC组, n = 10)和单尖充填技术(以GuttaFlow2为封闭剂, 以下称GF2组, n = 10)充填根管, 在距根尖2 mm(根尖部)、4 mm和6 mm(根中部), 以及距根尖8 mm(根冠部)处切片, 使用体视显微镜观察计算根管截面的空隙面积百分比。(2)选取离体恒磨牙轻、中、重度弯曲根管各16例, 同样分别采用热垂直加压技术(WVC组, n = 8)和GuttaFlow2单尖充填技术(GF2组, n = 8)充填根管, 使用激光共聚焦显微镜观察计算距根尖2 mm(根尖部)、5 mm(根中部)和8 mm(根冠部)处各个截面上封闭剂渗入牙本质小管区域的渗透百分比。结果: (1) 根管空隙面积百分比: GF2组和WVC组轻、中、重度弯曲根管根尖部均无明显空隙, 两组间差异无统计学意义(P＞0.05);根中部两种充填方法产生的空隙面积百分比差异也没有统计学意义; 但在根冠部GF2组相较于WVC组在轻度弯曲根管中出现了更多的空隙, 差异有统计学意义(P = 0.009)。(2)封闭剂对牙本质小管渗透百分比:GF2组在轻、中、重度弯曲根管根尖部, 封闭剂对牙本质小管渗透百分比分别为36.10%、55.80%、65.08%, 重度弯曲根管显著高于轻度弯曲根管(P = 0.001);组间比较提示, 根尖部GF2组轻、中、重度弯曲根管牙本质小管渗透百分比均明显高于WVC组(分别为15.78%、20.70%、15.61%, P = 0.001), 根中部GF2组轻、中度弯曲根管牙本质小管渗透百分比也明显高于WVC组(P = 0.001), 但根冠部两组间差异没有统计学意义(P＞0.05)。结论: 常温流动牙胶封闭剂单尖法充填弯曲根管在根尖和根中段对根管的封闭效果和热垂直加压技术相同, 而对牙本质小管则具有更好的渗透封闭效果, 尤其对于重度弯曲根管。

Objective: To evaluate the sealing ability of GuttaFlow2 single cone obturation in curved root canals. Methods: (1) Slight, moderate and severe curved 3D printed root canals were made. After instrumentation, these samples were randomly divided into 2 groups (n = 10) according to different root canal filling techniques: GuttaFlow2 single cone group (GF2) and AH-Plus warm vertical compation group (WVC). All the samples were sectioned at 2 mm to apex (the apical of the root), 4 mm, 6 mm to apex (the middle of the root) and 8 mm to apex (the coronal of the root). The filling void areas were observed by stereomicroscope, and the percentages of void areas in each section were calculated by ImageJ 1.52a. (2) Forty-eight roots of extracted adult molars were selected. After instrumentation, they were randomly divided into 2 groups (n = 8): GF2 group and WVC group. Before root canal filling, the sea-lers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2 mm to apex (the apical of the root), 5 mm to apex (the middle of the root) and 8 mm to apex(the coronal of the root). Then, the percentages of sealer penetration into dentinal tubules in each section were calculated. Results: At the apical of the root, there were no obvious voids in slight, moderate and severe curved canals in the GF2 group and the WVC group. There was no significant difference between the two groups (P > 0.05). At the middle of the root, there was no significant difference in the percentages of void areas between the two filling methods, but at the coronal of the root, there were more voids in the slight curved root canal in the GF2 group than in the WVC group, and the difference was significant (P = 0.009). The percentages of sealer penetration into dentinal tubules of slight, moderate and severe curved root canals in the GF2 group were 36.10%, 55.80%, 65.08%, respectively. And they were all higher than those in the WVC group (15.78%, 20.70%, 15.61%), respectively, the difference between the two groups was significant (P = 0.001). At the middle of the root, the percentages of sealer penetration into dentinal tubules of slight and moderate curved root canals in GF2 group were also significantly higher than those in the WVC group (P = 0.001). At the coronal of the root, there was no significant difference between the two groups (P > 0.05). Conclusion: GuttaFlow2 filling technique has the same sealing effect on the root canal at the apical and middle of the root as the warm vertical technique, but has a better sealing effect on the dentin tubules, especially for severe curved root canal.