根管预备器械及充填物对前磨牙牙体抗折强度的影响

目的:探讨根管锉及牙合面充填物对前磨牙牙体抗折强度的影响。方法:选取2017年2月~2018年11月本院拔除14~16岁正畸患者所得到的离体上颌第一前磨牙100颗作为研究样本,将其随机分为5组,每组20颗。其中A组为对照组不做任何处理,B和C组在不锈钢K锉预备根管之后分别充填光固化树脂和玻璃离子水门汀,D和C组在ProTaper手动锉预备根管之后分别充填光固化树脂和玻璃离子水门汀。对所有牙齿制作试件采用多功能力测量机对其破坏载荷进行测试,比较不同根管锉及牙合面充填物对前磨牙牙体抗折强度。结果:A组、B组、C组、D组和E组的破坏试验测量值分别为(1.03±0.08)F/kN、(0.99±0.08)F/kN、(1.01±0.04)F/kN、(0.65±0.05)F/kN和(0.68±0.03)F/kN。A组最高,但是与B组和C组比较差异无统计意义(P>0.05),与D组和E组比较差异有统计学意义(P<0.05)。结论:较ProTaper手动锉预备根管,不锈钢K锉预备根管的牙体抗折强度高,牙合面充填物光固化树脂和玻璃离子水门汀不影响牙体抗折强度。

The Effect of Root canal Preparation Equipment and Fillings on the Fracture Strength of Premolars

Objective: To investigate the effect of root canal file and occlusal filling on the fracture strength of premolars. Methods: 100 maxillary first premolars extracted from 14-16-year-old orthodontic patients in our hospital from February 2017 to November 2018 were randomly divided into 5 groups, 20 in each group. Group A was the control group without any treatment, group B and group C were filled with light cured resin and glass ionomer cement after stainless steel K file preparation of root canal, group D and group C were filled with light cured resin and glass ionomer cement after ProTaper manual file preparation of root canal. The fracture loads of all the teeth were measured by the multi-function capacity measuring machine, and the fracture strength of premolars with different root canal files and occlusal surface fillings were compared. Results: The measured values of damage test in group A, B, C, D and E were(1.03±0.08) f/kn,(0.99±0.08) f/kn,(1.01±0.04) f/kn,(0.65±0.05) f/kn and(0.68±0.03) f/kn, respectively. Group A was the highest, but there was no statistical significance compared with group B and group C(P>0.05), and there was statistical significance compared with group D and group E(P<0.05). Conclusion: Compared with ProTaper, stainless steel K file has a higher bending strength of teeth. Light cured resin and glass ionomer cement do not affect the bending strength of teeth.