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Objective To establish a floor structure and size of different orthodontic bracket dimensional finite element model , under the same conditions by comparing the different structures and bottom bracket area adhesive quality , analytical bottom bracket structure and quality of the bonding area for clinical use brackets , manufacturers theoretical and experimental studies provide a biological basis and reference . Methods orthodontic bracket three kinds of bottom structure and the five kinds of floor area , combined with CT scan images of human teeth as well as the average body measurement data , the establishment of teeth - adhesive - bracket system, three-dimensional finite element model , the model is applied same size tension, shear and torsional forces , analysis and calculation of the system under different loading conditions of stress distribution and displacement changes, compare different orthodontic brackets floor structure and size of the bonding quality. 1 , the establishment of 15 different floor area of the tooth structure and - adhesive - bracket dimensional finite element model of the system . Two , three kinds of loading modes , each interface in the system the maximum principal stress and Von-mises stress distribution are the main uneven . 3 , all three loading modes , the interface and the maximum principal stress Von-mises principal stress values are under tension maximum torsional force of the smallest . 4 shear resistance bracket with bottom bracket area increases, tensile strength and resistance to torsion when the bottom bracket length, width, floor area is best when quite area , with the subsequent increase of the area tensile strength and resistance to torsion changed little. 5 grid plate under the action of the three loading the maximum principal stress and Von-mises the maximum principal stress of the minimum and maximum values of the maximum displacement . Conclusions 1 . Single loading conditions , tensile adhesion interface more prone to damage. (2) In this experimental study within the bracket bonding strength with the floor area increases. 3 In other conditions consistent , grid plate and tilt than grooved grid floor has better tensile, shear and torsion characteristics strong adhesive properties than the other two .
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