口腔环境下不同时期正畸镍钛弓丝表面摩擦力及表面结构的变化

Changes in surface frictional forces and surface topography of orthodontic NiTi archwires in different phase

[目的]探讨口腔环境下镍钛弓丝不同时期表面摩擦力及结构的变化。[方法]在粘结托槽的上颌模具上,分别测量在排齐整平阶段未使用和使用1、2个月的0.014英寸、0.016英寸镍钛圆丝与托槽间的表面摩擦力。扫描电镜观察镍钛圆丝使用前后表面结构及粗糙度。[结果]使用1个月后镍钛弓丝的表面摩擦力比未使用的明显增大(P<0.05),使用2个月后者表面摩擦力增加更为显著(P<0.01)。电镜下使用后的镍钛圆丝表面粗糙度增加。[结论]镍钛合金丝在口腔环境使用一段时间后,其表面摩擦力和粗糙度均会明显增大。

[Objective] To investigate the changes in surface frictional forces and surface topography of NiTi archwires exposed to oral conditions in different phase.[Methods] On the testing maxillary model,we measured the static and kinetic friction of 0.014＂ and 0.016＂NiTi archwires with new,used one and two months in the alignment and leveling phase.Surface topography of each archwire was assessed by scanning electron microscope（SEM）.[Results] The surface frictional forces of 0.014＂ and 0.016＂ NiTi archwires increased significantly for 1 month（P0.05）,and more for 2 months after the archwires were exposed to oral condition（P0.01）.Surface roughness of the archwires increased significantly after used under SEM.[Conclusion] The surface frictional force and roughness of NiTi archwires would increase in the oral environment.