自调节根管锉预备下颌磨牙C形根管的体外研究

In vitro study of application of self-adjusting file in preparation of C-shaped canals in mandibular molars

目的比较自调节根管锉、机用ProTaper Universal锉和手动不锈钢K锉预备下颌第二磨牙C形根管的效果。方法收集具有C形根管的下颌磨牙27颗,分别用自调节根管锉、机用ProTaper Universal锉和手动不锈钢K锉预备根管,在根管预备前和预备后分别进行显微CT扫描和三维重建,评价各组器械根管预备后牙本质去除量和根管未接触面积百分比。结果在预备C形根管时,自调节根管锉组、ProTaper Universal锉组和手动不锈钢K锉组牙本质去除量分别为(9.20±2.09)mm3、(8.53±3.14)mm3和(18.65±5.23)mm3,手动不锈钢K锉组比ProTaper Universal锉组和自调节根管锉组牙本质去除量大,差异有统计学意义(P<0.05),ProTaper Universal锉组和自调节根管锉组间差异无统计学差异。根管预备后自调节根管锉组、ProTaper Universal锉组和手动不锈钢K锉组根管未接触面积百分比分别为(31.63±11.80)%、(51.71±14.07)%和(37.15±13.34)%,自调节根管锉组和手动不锈钢K锉组根管未接触面积百分比差异无统计学意义,且均较ProTaper Universal锉组小(P<0.05)。结论自调节根管锉预备下颌磨牙C形根管的效果优于手动不锈钢K锉和机用ProTaper Universal锉。

Objective Compare the shaping ability of self-adjusting file （ SAF） , ProTaper Universal and K-files in the preparation of C-shaped canals in mandibular molars by micro-CT technique. Methods Twenty-seven mandibular molars with C-shaped canals were collected and prepared with SAF, ProTaper Universal and step-back technique with K-files re-spectively. Micro-CT was performed before and after root canal preparation. Volume of dentin removed after preparation and percentage of uninstrumented area were measured and compared. Results Volume of dentin removal was statistically greater in group K-files （ 18. 65 ± 5. 23） mm3 than group ProTaper Universal （ 8. 53 ± 3. 14） mm3 and group SAF （ 9. 20 ± 2. 09） mm3（ P〈0. 05） . Difference between group ProTaper Universal and group SAF was not statistically significant. Percentage of uninstrumented area was statistically less in group SAF （ 31. 63 ± 11. 80）% than in group K-files （ 37. 15 ± 13. 34）% and group ProTaper Universal （ 51. 71 ± 14. 07）% （ P〈0. 05） . Conclusion SAF removed dentin homogene-ously in preparing C-shaped canal in mandibular molars, with better result than K-files and ProTaper Universal.