单尖法iRoot SP不同导入方式对根尖封闭性能和超填影响的模型研究

Model study on the influence of single-cone iRoot SP root filling method on apical sealing ability and overfilling

目的:通过Micro-CT评价单尖法iRoot SP不同导入方式对树脂直根管模型根尖5 mm封闭性能和超填的影响,以评估根管充填质量。方法:选取40个树脂直根管模型,工作长度均为16 mm,使用ProTaper Universal预备至F2,随机分为4组(n=10),分别为iRoot SP注射至根管冠方1/2、根管根方1/2、根管根中1/3和牙胶尖根方1/2,牙胶尖从根管口缓慢插入完成根管充填。应用Micro-CT测算根尖区5 mm存在空隙的横截面比例和充填材料体积比评估根尖封闭性能,根尖止点外封闭剂的超出体积以评估超填情况。结果:iRoot SP注射至根管根中1/3组根尖区5 mm存在空隙的横截面比例最小且充填材料体积比最大(P<0.05)。牙胶尖根方1/2组根尖止点外超出体积最少(P<0.05),其次是根管根中1/3组(P<0.05)。结论:4种iRoot SP导入方式在根尖5 mm区域均不能避免空隙产生,注射至根管根中1/3的根管充填质量最优。

Objective:Micro-CT in the single-cone technique was used to assess the quality of root canal filling by evaluating the influence of different iRoot SP import method on the apical 5 mm sealing ability and overfill of a resin straight root canal model.Methods:Forty resin straight root canal models with 16 mm working length were prepared to F2 using Pro-Taper Universal and randomly divided into 4 groups(n=10).iRoot SP was injected into 1/2 of the root canal crown,1/2 of the root canal apical,1/3 of the root canal middle and 1/2 of the gutta-percha point apical,respectively.Then,gutta-percha point insert slowly from the root canal orifice to complete the root canal filling.Micro-CT was used to measure the percentage of cross-sections with voids,the filling material volume percentage,and the excess volume beyond apical termination in the apical 5 mm area with voids seven days later.Results:The lowest cross-sections with voids and the highest filling material volume percentage in the apical 5 mm were seen with iRoot SP injected into 1/3 of the root canal middle(P<0.05).The guttapercha point apical 1/2 group had the least excess volume beyond apical termination(P<0.05),followed by the root canal middle 1/3(P<0.05).Conclusion:None of the 4 iRoot SP root filling methods can avoid voids in the apical 5 mm area.Root canal middle 1/3 provides the best filling performance.