口腔医学研究

口腔医学研究 ›› 2017, Vol. 33 ›› Issue (8): 820-823.DOI: 10.13701/j.cnki.kqyxyj.2017.08.005

• 基础研究论著 • 上一篇    下一篇

预加载疲劳应力对R-相镍钛锉表面形态及疲劳折断性能的影响

杨殷杰1, 侯本祥1, 侯晓玫2*   

  1. 1. 首都医科大学口腔医学院牙体牙髓科 北京 100050;
    2. 北京大学口腔医院第二门诊部 北京 100101
  • 收稿日期:2017-01-10 出版日期:2017-08-20 发布日期:2017-08-28
  • 通讯作者: 侯晓玫,电话:010-82196307
  • 作者简介:杨殷杰(1983~ ),女,四川人,硕士,主治医师,主要从事口腔内科的临床治疗工作。
  • 基金资助:
    国家自然科学基金项目(编号:81200826)

Influence of Pre-load on Surface Microstructure and Cyclic Fatigue Resistance of R-phase Rotary Files.

YANG Yin-jie1, HOU Ben-xiang1, HOU Xiao-mei2*.   

  1. 1. Department of Endodontics, Capital Medical University School of Stomatology, Beijing 100050, China;
    2. The Second Dental Center of Peking University School of Stomatology, Beijing 100101, China.
  • Received:2017-01-10 Online:2017-08-20 Published:2017-08-28

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摘要： 目的:比较K3XF和K3经过预加载疲劳应力后的表面形态和疲劳折断性能。方法:25 mm长、25#/0.06锥度的K3XF和K3各48支,随机分为4组(n=12),组1不做预加载。组2~组4分别使用60°弯曲角度、3.5 mm弯曲半径的模拟金属根管预加载疲劳应力5 s、10 s、20 s。每组随机选取2支锉在SEM下观察表面形态,其余10支锉使用上述模拟根管进行疲劳折断实验。记录疲劳折断时间,计算疲劳折断圈数;测量折断段长度,并对折断断口进行SEM观察。SAS 9.3软件进行双因素的方差分析,显著性水平0.05。结果:SEM见两种根管锉弯曲最大处的切割刃明显磨损、出现大量裂纹、边缘不整齐。K3XF表面缺陷明显少于K3。K3XF预加载疲劳应力20 s后的疲劳折断圈数从新锉的(210±59)降低为(156±37),差异有显著性(P<0.05)。K3预加载疲劳应力5 s、10 s、20 s后的疲劳折断圈数从新锉的(145±38)分别降低为(110±27)、(101±31)和(62±31),5 s和10 s组无显著差异,其余两两之间差异有显著性(P<0.05)。结论:K3XF对预加载疲劳应力的抵抗性优于K3。

关键词: 预加载应力, 疲劳折断, 镍钛根管锉, 扫描电镜, R-相

Abstract: Objective: To compare the effect of pre-load on surface microstructure and cyclic fatigue resistance of K3XF and K3. Methods:Forty-eight K3XF or K3 instruments #25/.06 were randomly divided into 4 groups (n = 12). The instruments from group 1 were not pre-loaded, and the group 2 to 4 underwent pre-load for 5s, 10s and 20s by using a simulated metal root canal with curvature of 60° and radius of 3.5 mm, respectively. The surface microstructure of two instruments randomly selected from each group was observed using SEM. Then the remaining 10 instruments were submitted to the cyclic fatigue test using the before mentioned apparatus. The time till fracture was recorded as well as the number of cyclic fatigue (NCF) and the fragment length. The topographic features were analyzed using SEM. The data were analyzed with the Two-Way ANOVA analysis at a significance level of P<0.05 by using SAS 9.3. Results:SEM observation demonstrated obvious flute abrasion, numerous cracks and irregularities on both of the files. However, this kind of destruction was less on K3XF than that on K3. Cyclic fatigue resistance of K3XF significantly decreased from (210±59) to (156±37) after pre-loaded for 20 s (P<0.05). Cyclic fatigue resistance of K3 decreased from (145±38) to (110±27), (101±31) and (62±31) after pre-loaded for 5s, 10s and 20s, respectively (P<0.05). Significant difference was observed between groups (P<0.05) except that between 5s and 10s groups. Conclusion: K3XF exhibits better resistance against pre-load compared to K3.

Key words: Pre-loaded, Cyclic fatigue , Nickel-titanium instrument , SEM R-phase

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