Elastics in orthodontics

Aim: The work assesses force characteristics of one type and size of elastics, specifically 3/16“ medium elastics, of five different manufacturers. We compared initial forces, and particularly the relationship between their force degradation over aɸperiod of time. Material and method: 500 latex elastics 3/16“ medium from Dentaurum, American Orthodontics, 3M, Ortho Organizers and G & H Orthodontics (100 of each) were tested. Force was measured with dynamometer at time 0, 2, 8, 24 and 48 hours. Elastics were stretched to triple of their original diameter and they were placed onto the plate manufactured by us. The plate was produced with 3D printer. Then everything was put into an incubator at the temperature of 37 °C and constant humidity. Shapiro-Wilk normality tests, ANOVA and Bonferroni’sɸpost-hoc tests were used for statistical evaluation. Individual manufacturers were asked whether they know in which plants exactly the elastic tractions are produced. Unfortunately, they did not answer the question. Results: The average initial force was between 1.109 N and 1.550 N; elastics made by Dentaurum were closest to the declared force of 1.255 N. The force decreased most during the first two hours. Between the individual producers the decrease of elastic tractions during 24 hours oscillated between 20 and 33%. The greatest drop in force was recorded for American Orthodontics products. The smallest decrease was recorded between 2nd and 8th hour for 3M, and between 24th and 48th hour for OrthoOrganizers products. Conclusion: Intermaxillary elastics of 3/16“ medium measured in vitro differ both in the amount of their initial force and in force degradation. Orthodontists should know the basic parameters of elastic tractions. To secure maximum care aɸdoctor should measure initial force of elastic tractions with dynamometer intraorally.