不同器械预备根管对隐裂牙牙体抗性影响的研究

Study on Cracked Tooth Resistance with Different Instruments in Root Canal Preparation

目的探讨使用不同器械预备根管对隐裂牙牙体抗性产生的影响。方法选取60颗上颌第一前磨牙作为研究对象,建立隐裂牙模型,按照随机配对的原则分为4组,各15颗:A组使用手用不锈钢K锉将根管预备至40#、锥度0.02;B组为M3-Pro机用镍钛锉预备至25#、锥度0.06;C组用TF机用镍钛锉预备至25#、锥度0.06。D组为对照组,不进行根管预备。各组根管治疗的步骤相同。用电子万能材料试验机做加载实验,分别观察并记录各组标本在试验机下最大受力值、隐裂牙模型折裂程度,对结果进行统计分析。结果对照组与各实验组间比较,差异有统计学意义(P<0.05),A组与B组、C组之间比较,差异有统计学意义(P<0.05),而B组和C组之间比较;差异无统计学意义(P>0.05)。而折裂程度与器械的选择没有统计学差异。结论使用不同器械预备隐裂牙根管后,对牙体抗折性有影响,可减少牙齿折裂的风险。机用镍钛锉与手用不锈钢K锉相比牙体的抗性降低。

objective To compare the fracture resistance of cracked tooth with different instruments to prepare the root canal.Methods Sixty maxillary first premolars made tooth cracked model and randomiy divided into 4 groups with 15 in each group.In Group A,the root canal was prepared to 25#using a stainless steel K-file with a taper of 0.02;B group M3-Pro machine nickel-titanium file preparation to 25#,taper 0.06;C group with TF machine nickel-titanium file preparation to 25#,taper 0.06.No root canal preparation in control Group D.Root canal treatment was the same steps.All specimens were subjected to a vertical load to cause root fracture.The force required to fracture was measured and the fracture lines was classified.Result The control group and each experimental group was statistically significant(p<0.05).There was a significant difference between group A and group B and group C(p<0.05),but there was no significant difference between group B and group C(p>0.05).There was no significant difference between the degree of fracture and the choice of equipment.Conclusion Choosing different devices can influence the strength signicantly and reduce the risk of tooth fracture.Compared machine with nickel titanium file and hand with stainless steel K file,the former can reduce dental resistance.