Different Bottom Structure Of Dental Brackets Affect The Adhesiveness-Three Dimensional Finite-element Analysis

Objective: The study was designed to reduce the cost of production of dental bracket.We built four different bottom structure of dental brackets model in the method of three dimensional finite element analysis on computer frist. And analysed the variability of the stress distribution and the maximum deformation of each model, thus assess the quality of adhesiveness affected by each bottom structure. Hoping to provide some valuable reference to the clinician and the bracket producer.Methods: Establish the three-dimensional models of dental bracket on computer in the light of the statistical data of teeth size of Chinese people. The bottom structures of dental bracket including inverted trapezium grooves, square gridding, triangle gridding and parallelogram gridding. After the establishment, we exerted the same power of forces respectively such as tension, shearing force, rotation on the ears of brackets. To calculate and read the maximum records of stress distribution and the maximum deformation under the three forces, the less stress and deformation, the better of the retention of bottom structure on adhesiveness.Results: 1) Four braces floor in the same way the stress distribution under loading and deformation rule similar. The regularity of distribution on stress and deformation of the four brackets under the same application of force is similar. 2) Under the tension, there's no significant difference of stress distribution among the four bottom structure types brackets. The rhombus gridding bottom has the highest record of maximum von-mises stress, it is 5.76Pa. The triangle gridding bottom's maximum von-mises stress is lowest among the four, it is 5.54 Pa. Under the shearing force, the rhombus gridding bottom's maximum von-mises stress is highest, it is 5.31Pa, the square gridding bottom's maximum von-mises stress is lowest, it is 4.27Pa. Under the rotational force, the rhombus gridding bottom's maximum von-mises stress is highest, it is 8.19 Pa. The triangle gridding bottom's maximum von-mises stress is lowest, it is 7.59 Pa. 3) Under the tension, the undercut slot bottom has the largest deformation, it is 6.8 m^-8.The triangle gridding bottom has the smallest deformation, it is 5.44 m^-8. Under the shearing force, the triangle's deformation is largest, it is 12.05 m^-8. The undercut slot bottom's deformation is smallest, it is 10.89 m^-8. Under the rotational force, there's no significant difference among the four types bottom, the largest deformation is in rhombus gridding bottom, it is 12.19 m^-8. The smallest deformation is in triangle gridding bottom, it is 11.88m^-8.Conclusion: 1) Under the three types of application of stress on the dental brackets, the shearing force has the best anti-destruction ability, the square gridding bottom has the best anti-destruction ability among the four types bottom; The rotational force is most apt to break the adhesiveness, the triangle gridding bottom's anti-destruction ability is a little better than others; In anti-destruction, there's no significant difference of the four types bottom. 2) Under the three types of application of stress on the dental brackets, the tension has the best anti-deformation ability, and the triangle gridding bottom has the best anti-deformation ability among the four types bottom. The shearing force's anti-deformation is in the middle, the undercut slot bottom's anti-deformation is best among the four types bottom. The rotational force is most apt to deformation, especially the rhombus gridding bottom. 3) Combining the stress and deformation application of the four types bottom, the new desire of triangle gridding bottom has the relatively better retention effect, and rhombus gridding bottom's retention effect is relatively worse than others.