The Study Of 24 Hours-elastic Attenuation In Orthodontic Latex Elastics

Objective To analyze the decay of elasticity value of the orthodontic latex elastics in the mouth within 24 hours.Methods Six different kinds of orthodontic latex elastics commonly used in clinic were chosen.The elastics were divided into 1/4inch(3.5oz),1/4inch(2oz),5/16inch(3.5oz),5/16inch(2oz),3/8inch(3.5oz)and 3/8inch(2oz)groups according to inner diameter and elastic parameter.Personalized film retainer was made for holding the orthodontic latex elastics with specific length in mouth,then measured the elasticity value at 0,0.5,1,1.5,2,3,4,6,10,16,24 hours.Results The elasticity value of all groups decreased sharply in early 1.5hours,then the decay rate slowed down,the elastic attenuation was 15.6%-18.8% after 24 hours.When tested at the same time point,the elastic attenuation of the 3.5oz group is smaller than that of the 2oz group,meanwhile,under the same setting elastic value,the greater the inner diameter of the elastic,the smaller the attenuation of the elastic force(3/8in.<5/16 in.<1/4in.)(p<0.05).Conclusion The elasticity value of the orthodontic latex elastics decreased sharply in early 1.5hours.The larger the inner diameter and the setting force value,the slower the elasticity value decay,indicating that elastics should be change appropriately in clinics.