RESUMEN
Objective: To evaluate and compare the effect of variation in storage temperatures and duration on a tensile load at failure of elastomeric modules. Methods: In total, 140 modules were used in the study, 20 of which were tested on day 0 as received from a company using a Universal testing machine for baseline estimation of tensile load at failure. The rest 120 modules were divided into 6 groups. Groups I, II, and III modules were stored at low (T1 = 1–5°C), moderate (T2 = 20–25°C) and high (T3 = 35–40°C) temperatures, respectively, for 6 months. Groups IV, V and VI modules were stored at temperatures T1, T2 and T3 for 1 year, respectively, and were tested for tensile load at failure. Results: The tensile load at failure for the control group was 21.588 ± 1.082 N and for 6?month interval at temperatures T1, T2 and T3 was 18.818 N ± 1.121 N, 17.841 N ± 1.334 N and 17.149 N ± 1.074 N, respectively, and for 1 year, it was 17.205 N ± 1.043 N, 16.836 N ± 0.487 N and 14.788 N ± 0.781 N, respectively. The tensile load at failure decreased significantly from 6 months to 1 year among each temperature group. Conclusions: Maximum force degradation was seen in modules at high temperature followed by medium temperature and low temperature at both 6 months and 1 year intervals, and tensile load at failure decreased significantly from 6 months to 1 year storage duration. These results conclude that the temperature and duration at which the samples were exposed during storage produce a significant change in the forces exerted by the modules.
RESUMEN
The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of in-creased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of ortho-dontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticea-ble force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads.