摘要
目的:计算不同刚度的无托槽隐形矫治器扩大上颌牙弓时牙周膜的应力大小、分布特点及旋转中心距根尖的距离,为材料选择和设计理念提供理论依据。方法:建立弹性模量分别为415.6、816.31、2400 MPa的3个隐形矫治器,上颌前磨牙、磨牙设计颊向移动0.3 mm的有限元模型,分析牙周膜应力分布状况。结果:实验条件下,A组、B组、C组的应力分布趋势相似,其唇侧颈部由压应力向根尖转变为拉应力,舌侧颈部由拉应力向根尖转变为压应力。在根尖,根分叉和颈缘都有应力的集中区,A组的应力集中区面积最大,其次是C组,B组应力集中区面积最小。牙齿的旋转中心均位于根中1/3与根尖1/3交界附近。隐形矫治器扩大上颌牙弓时,牙周膜的瞬时最大应力值随矫治器材料的弹性模量的增加而增加。结论:无托槽隐形矫治器扩大上颌牙弓时,刚度越大,矫治器和牙周膜产生的应力越大,上后牙趋向于颊向的倾斜移动。
Objective:To analyze the stress value,distribution characteristics of periodontal ligament,and the distance between the center of rotation and the root tip when using invisible appliance with different material stiffness to expand upper dental arch.Methods:Three-dimensional finite element models with elastic modulus at 415.6,816.31,and 2400MPa were established.The upper premolars and molars were designed to buccally move 0.3mm to analyze the stress distribution.Results:Under experimental condition,the stress distribution tendency of group A,group B,and group C was similar.Specific performances:buccal cervical 1/3 was compressive stress,toward the apex gradually transiting to the tensile stress.The stress distribution on the lingual side was contrast.Specific performances:the lingual cervical 1/3 was tensile stress,toward the apex gradually transiting to the compressive stress.In three models,stress concentrated in the areas of apex,root bifurcation,and neck.The area of stress distribution was:Group A>Group C>Group B.In these groups,center of teeth rotation was located in the area of the junction of middle 1/3 and apex 1/3.Expanding upper dental arch,the elastic modulus of the appliance increased and the stress increased.Conclusion:The bigger the hardness of clear aligners,the bigger the stress in periodontal ligament and aligners.Upper premolars and molars tended to move buccally.
作者
苏涛
王星星
向彪
吴刚
邹敏
SU Tao;WANG Xingxing;XIANG Biao;WU Gang;ZOU Min(Department of Orthodontics, Hospital of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China;Shanghai Smartee Technlogy, Shanghai 201210, China)
出处
《口腔医学研究》
CAS
北大核心
2020年第5期454-458,共5页
Journal of Oral Science Research
关键词
三维有限元分析
无托槽隐形矫治器
牙周膜
应力分析
弹性模量
刚度
three-dimensional element analysis
Clear removable orthodontic appliances
periodontal ligament
stress analysis
elastic modulus
stiffness
