Evaluation of the standardization of the initial released force by chain orthodontic elastics

Vol. 16 – Number 61 – 2023 Original article Page 56-61 Evaluation of the standardization of the initial released force by chain orthodontic elastics Viviane Rodrigues Amorim¹ Laura Mello Figueiredo¹ Edgard Norões Rodrigues da Matta² Abstract This study evaluated the standardization of the initial strength delivered by elastomeric chains of different lots of fabrication of three commercial brands. 762 colorless middle size samples of elastomeric chains were tested of the brands Morelli®, Uniden® and Eurodonto®. The elastics were distributed in 6 different groups: Group M (Morelli), Group U (Uniden) and Group E (Eurodonto), with 2 lots for each group. The elastics were maintained in a “jig” of 07 x 07 cm acrylic one that was fixed in a 55 X 15 cm wooden base. The elastics were activated in 50% of his initial lengths and the released inicial force was measured through a digital precision dynamometer. Kolmogorov-Smirnov tests were used and Student “t” test with 5% of significantion for both tests. The results showed significant difference between the mean initial released force of 336.84g and 270.72g of lots 1 and 2, respectively, of brand U. There was no significant difference between lots of brand M presenting average initial force of 310.31g and 312.77g and brand E with initial forces of 378.42 and 377.91. Groups M, U and E presented the percentages of 8.7%, 4.3% and 11.4%, respectively, of elastic samples releasing initial strength considered standardized. It can be concluded that the Morelli® and Eurodonto® brands showed standardized initial strength when variations between lots were investigated. However, all commercial brands had a very low percentage of elastic samples with standardized initial strength, considering the confidence interval. Descriptors: Elastomers, polyurethanes, elasticity, corrective orthodontics. ¹ Specialization Course in Orthodontics – Centro Universitário CESMAC. ² Discipline of Orthodontics – UFAL. DOI: 10.24077/2023;1661-0187939