A Finite Element Analysis Of Mechanical Capabilities Of The DamonQ System Using The Double Wire Technique

Objective: The purpose of this study is to do the finite element analysis of mechanical capabilities of the DamonQ system using the double wire technique by using three-dimensional finite element method for establishing different dimensional and material finite models of the rectangular wire,round wire and DamonQ brackets.With the mechanical comparison study of torque and tip of single rectangular wire,single round wire,rectangular-round double wires and round-round double wires,we can understand more about mechanism of the double wire system and explore the mechanical properties of Damon system using double wire technique.Methods:1.In Pro/E Wildfire5.0 software,the central incisor,lateral incisor,canine DamonQ(Ormco,Glendora,CA,America)bracket and archwire models were established in a total of 29 groups.The bracket slot size 0.022 x 0.028 inch,archwire size 0.016 x 0.025 inch(0.41 x 0.64 mm~2)rectangular wire and 0.012,0.014,0.016 inch(diameter 0.30 mm,0.36 mm,0.41 mm)of round wire were established.Wire length of 30 mm was used and there all were saved in the STEP format.2.Completed assembly model of the Damon Q brackets and archwire were imported into CADfix8.0 software to repair,using rapid and comprehensive NURBS surface repair function of the CADfix8.0 software for removing duplicate points,edges and repairing unconnected surface model.3.The solid models in IGES imported MSC.Marc.Patran2005R3 software were grouped and the finite mesh elements were divided,we can obtain the finite element model of DamonQ brackets and archwires.4.By using the software MSC.Marc.Mentat2005R3,the model parameters of different boundary conditions,material properties and friction coefficient,contact relationship were set.With lateral incisor bracket slot center node as the center point,the torque displacement of 20 degrees was applied in counterclockwise rotation thein Y-axis horizontal axis and tipping displacement of 20 degrees in clockwise rotation in the Z-axis horizontal axis was applied.5.Under the different condition of rotational displacement,archwire reaction force were collected by the software MSC.Marc.Mentat2005R3,to draw the corresponding moment /angle curve and force value histogram.Results:1.The Damon Q brackets with single or double wires have the same variation of torque: While increasing torque angle,torque moment increased gradually.Rectangular-round double wires produced larger torque moment compared to single rectangular wire whereas double round wires produce smaller torque moment compared to single rectangular wire;the torque moment produced by rectangular-round double wires is about 2~8 times than double round wires and the torque moment by single rectangular wire is about 1~5 times than that one.On Comparing of mechanical property of round-round double wires it shows that the torque produced by Australian wire is about 3 times than that of the nickel titanium wire.2.With tipping movement of single wire,rectangular-round double wires and round-round double wires,it was noted that with the increase of the size of the main and auxiliary wire,the force value increased and the influence of the auxiliary arch wire was found to be greater than that of the main archwire.3.Tipping moment of 0.016 inch,0.014 inch,0.012 inch auxiliary single archwires were approximately 8.36,4.39,4.66 times than that of the same size main archwire,respectively.4.The torque loading curve results found that the first bend of 16×25 NiTi,12NiTi+16×25 NiTi,14NiTi+16×25 NiTi,16 NiTi+16×25NiTi was about 8 degrees,7 degrees,4degrees,1 degrees,respectively.Tip of the results show that the first bend of 16×25 NiTi,12NiTi+16×25 NiTi,14NiTi+16×25 NiTi,16NiTi+16×25NiTi was about 5 degrees,4 degrees,2.5 degrees,0.5 degrees,respectively.In the same angle,tipping force value is greater than the torque value.Conclusions:1.The construction of finite element model of the DamonQbracket and double archwires using a variety of software provides a reliable method for the study of the biomechanical properties of Damon Q system with the use of different material and dimensional combinations of double wires.2.Auxiliary round archwire plays the main role while using rectangular-round double wires before the torque angle of 8 degrees and there are the synergy effects of both after 8 degrees.Whereas in cases of round-round double wires the main arch wire has no torque effect,the torque effect is only applied by auxiliary round archwire.3.The rectangular-round double wires in Damon Q system synergistically enhanced the root control effect.Round-round double wires’ lever is about 2 times than that of the single wire,and the bigger force arm leads to smaller force value,so the strength of round-round double wires is softer.4.With the increase of tip angle,tip moment value increases,and tip moment value of double wires is greater than that of single wire.With the increase of the size of the main wire and the auxiliary wire,the value of tip force increases.Since the main tip force values come from auxiliary wire effect,main wire is less influential 5.With torsion teeth corrected by the rectangular wire,we can find tip play is less than torque play whereas teeth movement of tip and torque,we can find tip moment value is greater than torque moment in the same angle.6.The single wire is used for aligning the teeth when the anterior teeth keep larger rotation in orthodontics Clinic,adding double wire further helps in correctional tipping after decreasing the torsion angle.In the initial stage of the root control,we can use double round wires to control root movement.In the middle of the treatment,we can use rectangular-round double wires to control root movement as the mild forces produced by them reduces root absorption.7.The study lays a theoretical foundation for the application of DamonQ bracket with double wire technology in clinic.