An In-Vitro Comparison of Force Loss of Orthodontic Non-Latex Elastics

Objective: the amount and consistency of the applied forces to the tooth are im-portant factors in tooth movements; therefore, the aim of this study was to com-pare the initial force and the force loss of three brands of elastics in 24 hours.materials and methods: in this in-vitro study sixty non-latex elastics (3/16 me-dium) from three companies (forestadent, dentaurum and ortho technology) were randomly selected. two static tests were performed, the first in a dry envi-ronment to evaluate the initial force and the other performed in a wet environment (artificial saliva) to evaluate the force loss in 24 hours. the universal testing ma-chine measured the forces after stretching the elastics to three times the lumen di-ameter. data were analyzed by repeated measures anova, one-way anova, tukey-hsd, paired samples test, and one sample test.results: the difference between the brands was significant (p=0.002). force loss was observed in all samples; 4-7.5% force loss occurred after one hour and 19-38% force loss occurred after 24 hours. the average initial force of forestadent and ortho technology was significantly higher than marketed forces (p<0.001), but the initial force of dentaurum elastics was similar to the marketed force.conclusion: the force loss over 24 hours time period was foresta-dent>dentaurum>ortho-technology. according to the initial force and force loss percentage it is suggested to replace the non-latex elastics several times a day.