Force Degradation of Elastomeric Chains after Storage Time and Mechanical Brushing

Abstract

The purpose of this in vitro study was to evaluate the force decrease of different elastomeric chains after different times: initial, 10 minutes, 1 day, 28 days and after mechanical brushing. Twenty orthodontic elastomeric chains segments were utilized for each commercial brand. Initially, the elastomeric chain of 15mm long were immediate stretched up to 20 mm in an Instron and the force was measured in gf. After all specimens were placed stretched on rectangular acrylic jigs with distance of 20 mm, immersed in deionized water at 37oC for 10 minutes and the force (gf) was measured again. Five test measurements of remaining force were made at the following time intervals: initial, 10 minutes, 1 day, 28 days and mechanical brushing. After 28 days, the acrylic plates with the specimens were adapted in the mechanical brushing machines (MSCT 3) and the elastomeric chains were submitted to mechanical brushing and the force (gf) measure again. The force (gf) was submitted to mixed-model ANOVA and Sidak post-hoc test (α=0.05). A statistically significant reduction in the force was found for all orthodontic elastomeric chain types after 1 day, 28 days and mechanical brushing (p<0.05). Morelli and 3M Unitek elastomeric chains showed significantly higher force than Abzil and GAC (p<0.05) after 1 day, 28 days and mechanical brushing. In conclusion, the force delivered by all elastomeric chains decayed rapidly over time. Morelli and 3M Unitek elastomeric chains consistently had a significantly greater force after mechanic brushing, while GAC the lowest.

Effect of filament types and loops number on the force degradation of elastomeric chains used for orthodontic treatment: an in-vitro study

“…As the number of loops increases, the force degradation rate decreases. Other variables include the material used to make the loops [ 3 ]; and oral environments, such as the presence of saliva or different types of oral bacteria [ 1 , 5 , 7 , 32 ] and color stability [ 4 ] on the degradation of elastomeric chains.…”