Effect Of Orthodontic Protective Wax On Friction Of Metal Wire Brackets In Vitro

The influence of orthodontic protective wax on the friction of metal wire brackets and bow wire was discussed.It provides certain reference for clinical application of orthodontic protective wax.Method: The metal straight wire bracket with groove size of 0.022×0.025 inch was matched with the nickel titanium round wire of 0.014 inch and the stainless steel square wire of 0.019×0.025 inch respectively.The two samples were divided into four groups according to the random number table method: the metal ligated wire coated with protective wax group and the metal ligated wire control group.The ligated rubber band coated with protective wax group and the ligated rubber band control group.The dynamic and static friction force of the bow wire sliding along the bracket was measured by Intron universal material mechanics testing machine.All data were statistically analyzed and processed by SPSS20.0 software,and all data were expressed as mean ± standard deviation.Paired t test was used for comparison of experimental data.Result: 1.When the orthodontic protective wax was used,the static friction force between the metal wire bracket ligated with metal wire and the 0.014-inch niti wire increased by 2.81±1.55 N and the dynamic friction force increased by 2.01±0.82 N,and the differences were statistically significant(P<0.05).2.When the orthodontic protective wax was used,the static friction force between the metal wire bracket ligated with a rubber band and the 0.014-inch niti round wire increased by 1.74±1.56 N and the dynamic friction force increased by 0.12±1.73 N,and the differences were statistically significant(P<0.05).3.The static friction force between the metal wire bracket and the wire was increased by 2.38±1.35 N,and the dynamic friction force was increased by 1.59±1.12 N,and the difference was statistically significant(P<0.05).4.Compared with non-protective wax,the static friction force between the metal wire bracket ligated with the rubber band and the 0.019×0.025 bow wire increased by 1.83±2.48 N and the dynamic friction force increased by 1.25±2.30 N,and the differences were statistically significant(P<0.05).Conclusion: The static friction force and the dynamic friction force between the metal wire bracket and the bow wire will increase after the use of orthodontic protection wax,whether the ligation wire or ligation rubber band ligation,whether the use of 0.014 inch niti round wire or 0.019×0.025 inch stainless steel square wire.