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目的:制备后磨牙模拟根管模型。方法:依照预实验中测试的牙本质和树脂根管模型材料的布氏硬度值(牙本质HB72,树脂块HB54)选取纯铜质铜管为材料(纯铜HB58)同时利用预实验中确认的后磨牙模拟根管模型弯曲角度的范围(70°-60°)并参照树脂根管模型相关数据,设计不同弯曲角度(70°,64°,60°)的纯铜质根管模型,将20套镍钛根管锉随机分为4组,其中3组根管锉分别预备相应角度的10个纯铜质后磨牙根管模型,另一组在临床预备10个后磨牙根管作为对照组。所有镍钛根管锉均在疲劳寿命测试装置中测试疲劳寿命。结果:选用根管长度为16mm±1mm,弯曲半径为5mm,内径为0.70mm的纯铜质铜管制作后磨牙根管模型。其中在弯曲角度为70°的后磨牙根管模型中有33%(2/6)近似临床;在弯曲角度为64°的后磨牙根管模型中有67%(4/6)近似临床;在弯曲角度为60°的后磨牙根管模型中有33%(2/6)近似临床。结论:弯曲角度为64°的纯铜制后磨牙模拟根管模型更接近于临床实际,可为体外研究镍钛根管锉各项指标提供一个较为理想的模型。
Objective: To prepare postmortem simulated root canal model. Methods: According to the Brinell hardness (dentin HB72, resin block HB54) of the root canal model materials of dentin and resin tested in the pre-experiment, pure copper copper tube was selected as the material (pure copper HB58) The posterior molar model was used to simulate the range of bending angle (70 ° -60 °) of root canal model. The root canal model with different bending angles (70 °, 64 °, 60 °) was designed according to the data of resin root canal model. Set of nickel-titanium root canal files were randomly divided into 4 groups, of which 3 groups of root canal files were prepared at the appropriate angle of 10 pure copper posterior molar root canal model, the other group in the clinical preparation of 10 post-molar teeth as a control group. All NiTi files are tested for fatigue life in a fatigue life test set. Results: The root canal model of post-molar was made by using pure copper brass with a root canal length of 16mm ± 1mm, a bending radius of 5mm and an inner diameter of 0.70mm. Among them, 33% (2/6) of the posterior molar root canal models with a bending angle of 70 ° were approximately clinically; 67% (4/6) of the posterior molar root canal models with a bending angle of 64 ° were approximately clinically; 33% (2/6) of the posterior molar root canal models with a bending angle of 60 ° were approximately clinically. CONCLUSION: The model of pure copper posterior molar simulated root canal with a bending angle of 64 ° is closer to clinical practice, which can provide an ideal model for in vitro study of various indexes of nickel-titanium root canal files.