目的·比较根管内氢氧化钙（calcium hydroxide，CH）残留与根管充填方法对根尖封闭性的影响，为临床选择根管封闭药物及充填方法提供参考。方法·收集于青岛大学附属医院口腔颌面外科因正畸治疗或牙周问题拔除的下颌单根管恒前磨牙75颗，截冠，根管预备，随机分3组：水溶性氢氧化钙组（A组，n=30）、油溶性氢氧化钙组（B组，n=30）、未封药组（C组，n=15）。封闭2周后，A、B组使用35#K锉手动预备，并进行超声荡洗及冲洗根管，确保氢氧化钙残留位置大致位于根尖，且残留量为15%~20%。将A、B、C组的组内再各随机分为3组：爱汝特SP根管充填材料（injectable root canal sealant，iRoot SP）单尖法组（1组）、热压胶组（2组）、冷侧压组（3组），分别使用iRoot SP单尖法、热牙胶垂直加压充填法，以及冷牙胶侧方加压充填法进行根管充填。使用染料渗入试验评价根尖微渗漏情况，使用扫描电子显微镜观察各组牙本质与根管封闭剂界面的微观形态。采用两因素方差分析进行统计分析。结果·根管封闭药物与根管充填方式均会对根尖封闭性产生影响，且二者存在交互作用。分析残存氢氧化钙对根尖封闭性的影响，油溶性氢氧化钙组（B组）和未封药组（C组）仅在iRoot SP单尖法组（1组）的差异有统计学意义；水溶性氢氧化钙组（A组）与未封药组（C组）在热压胶组（2组）以及冷侧压组（3组）的差异有统计学意义；并且无论采用何种根充方式，水溶性氢氧化钙组（A组）和油溶性氢氧化钙组（B组）之间的差异都具有统计学意义。观察3种根充方式对根尖封闭性的影响，未封药组（C组）中iRoot SP单尖法组（1组）和冷侧压组（3组）相比，差异具有统计学意义（P=0.013）；在水溶性氢氧化钙组（A组）和油溶性氢氧化钙组（B组）中，热压胶组（2组）、冷侧压组（3组）与iRoot SP单尖法组（1组）的差异均具有统计学意义（P<0.001）。结论·残留在根管内的水溶性氢氧化钙对于根尖封闭性有不良影响，但残留的油溶性氢氧化钙对根尖封闭性的消极影响较小；iRoot SP能减少残存的水溶性氢氧化钙药物对于根管封闭性的不良影响。

Objective ·To compare the effects of calcium hydroxide (CH) residues in root canals and root canal filling methods on apical closure, and to provide reference for clinical selection of root canal sealing drugs and filling methods. Methods ·Seventy-five permanent mandibular premolar teeth with single root canals that were extracted due to orthodontic treatment or periodontal problems were collected from the Department of Oral and Maxillofacial Surgery of the Affiliated Hospital of Qingdao University. The crowns were removed, the root canals were prepared, and the specimens were randomly assigned into 3 groups: a water-soluble calcium hydroxide group (Group A, n=30), an oil-soluble calcium hydroxide group (Group B, n=30), and an unsealed control group (Group C, n=15). After 2 weeks of sealing, Groups A and B underwent manual preparation with a #35 K-file, followed by ultrasonic agitation and irrigation of the root canal to ensure that the calcium hydroxide residue was located roughly at the root apex and that the residue was 15% to 20%. Groups A, B, and C were randomly divided into 3 groups: the iRoot SP single-tip group (Group 1), the hot compression group (Group 2), and the cold compression group (Group 3), and root canals were filled using the iRoot SP single-tip method, the hot adhesive vertical compression filling method, and the cold adhesive lateral compression filling method, respectively. A dye penetration test was used to evaluate apical microleakage, and scanning electron microscopy was used to observe the microscopic morphology of the dentin-root canal sealer interface in each group. Statistical analysis was performed using two-way ANOVA. Results ·Both root canal sealing drugs and root canal filling methods affected the apical sealing, and there was an interaction between them. The effects of residual calcium hydroxide on apical closure were analyzed. The difference between Group B and Group C was statistically significant only in Group 1. There were statistically significant differences between Group A and Group C in Group 2 and Group 3, and statistically significant differences between Group A and Group B regardless of the root filling method. Among the three root filling methods, there was a statistically significant difference between Group 1 and Group 3 in Group C (P=0.013). In Group A and Group B, there were statistically significant differences between Group 2, Group 3 and Group 1 (P<0.001). Conclusion ·The residual water-soluble calcium hydroxide in the root canal has a negative effect on the apical closure, but the residual oil-soluble calcium hydroxide has a small negative effect on the apical closure. iRoot SP can reduce the negative effect of residual water-soluble calcium hydroxide on root canal closure.