Shyagali Tarulatha R, Urs Chandralekha Basavaraj, Subramai Shashikala, Bhayya Deepak P
Department of Orthodontics and Dentofacial Orthopedics, Darshan Dental College and Hospital, Loyara, Udaipur, India.
Orthodontics (Chic.). 2012;13(1):e66-75.
To analyze the influence of bracket base mesh geometry on the stresses generated in the tooth-cement-bracket continuum by a shear/peel load case and to compare the stress generated by three different loads (masticatory, peel, and twisting) on the bracket mesh base by employing a three-dimensional (3D) finite element computer model.
A validated 3D finite element model of the bracket-cement-tooth system was constructed consisting of 40,536 nodes and 49,201 finite elements.
An increase in the diameter of the bracket mesh base wire resulted in a decrease in the stress at the enamel and cement. Increase in wire spacing (200 to 500 mm) increased the stresses in the enamel and cement at all wire diameters, but within the impregnated wire mesh, the major stress decreased with the increase in the wire spacing. Peel load produced comparatively less stress on enamel than masticatory and twisting force.
Alteration in mesh spacing and wire diameter influences the magnitude and distribution of stresses within the bracket-cement-tooth continuum. Peel load and twisting load are best to debond the bracket since they produced minimal stress on the enamel, which is suggestive of lower chances of enamel damage.
通过剪切/剥离载荷情况分析托槽基底网格几何形状对牙-黏结剂-托槽连续体中产生的应力的影响，并采用三维（3D）有限元计算机模型比较三种不同载荷（咀嚼、剥离和扭转）作用于托槽网格基底时产生的应力。
构建了一个经过验证的托槽-黏结剂-牙齿系统的3D有限元模型，该模型由40,536个节点和49,201个有限元组成。
托槽网格基底丝直径增加导致牙釉质和黏结剂处的应力降低。丝间距增加（从200至500毫米）会使所有丝直径下牙釉质和黏结剂中的应力增加，但在浸渍丝网格内，主应力随着丝间距的增加而降低。与咀嚼力和扭转力相比，剥离载荷在牙釉质上产生的应力相对较小。
网格间距和丝直径的改变会影响托槽-黏结剂-牙连续体中的应力大小和分布。剥离载荷和扭转载荷最有利于使托槽脱黏，因为它们在牙釉质上产生的应力最小，这表明牙釉质受损的可能性较低。
