Experimental Evaluation of Strength Degradation of Orthodontic Chain Elastics Immersed in Hot Beverages

Abstract

Introduction: Elastomeric chains are relevant in orthodontic mechanics due to the form memory property; however, elastomers present high force reduction in some circumstances. The objective was to evaluate the effect of hot beverages on tensile strength degradation of orthodontic elastomeric chains. Material and Methods: Four groups were tested according to different immersion liquids: artificial saliva (group 1), hot water (group 2), green tea (group 3), and coffee (group 4). The elastomeric chains of groups 2, 3, and 4 were immersed in the respective liquids, with temperature of 70 ± 1°C twice daily for 30 seconds for a period of 7, 14, or 21 days. All samples were kept in artificial saliva and stored in an incubator at controlled temperature of 37 ± 1°C. The elastomeric chains were then examined in the testing machine (AME-2kN; Filizola, São Paulo, Brazil) to measure the tensile strength degradation. Results: It was observed through intragroup comparisons that the control showed a progressive reduction of tensile strength in a statistically significant manner throughout the study period. In turn, the hot water, green tea, and coffee samples showed a statistically significant reduction from 7 to 14 days. From 14 to 21 days, the tension remained stable. When the test groups were compared with the control, it was observed that all groups presented tension reduction in a statistically significant manner at all periods, except for the coffee group at 21 days ( P < .001). Conclusions: Experimental immersion in hot water, green tea, and coffee at 70 ± 1°C contributed in a statistically significant manner to the strength degradation of orthodontic elastomeric chains in the period of 7 and 14 days.

Effect of sodium fluoride in chlorhexidine mouthwashes on force decay and permanent deformation of orthodontic elastomeric chain

“…1 Orthodontic elastomeric chains have an ability to return to its original dimensions when subjected to deformation forces. 4 The applied force makes the molecules of polymer uncoiled; at first, the activated chain is stretched but as time passes, the molecules slip on each other, which results in force decay and permanent deformation. 10 Environmental factors for our study was controlled to CHX concentration of immersion solution, humidity of the environment, stayed in room temperature, force applied, no color to the elastomeric chain, because any of differences to environmental such like water, temperature, pH and time also cause a force decay in orthodontic elastomeric chain.…”

“…3 Due to its elastic ability, orthodontics elastomeric chain can return to its original dimensions when subjected to deformation forces. 2,4 Orthodontics elastomeric chain are used in any movement that requires pulling, such as tooth derotation, canine and incisor retraction, mild space closure, midline correction, mesial displacement in the posterior quadrants, and traction of impacted teeth. 5,6 According to the length of filament, orthodontics elastomeric chain divided into closed chain, short link chain, medium link chain and long link chain.…”

Does mouthwash degrade the force of orthodontic latex elastics?

“…After being loaded over its stress limit, latex elastic becomes fatigued at the weak places due to the lack of homogeneity on the inside or surface of the latex elastic. Dynamic fatigue also develops due to friction between the molecular chains [6]. Owing to the physical and chemical characteristics of latex, orthodontic elastics get fatigued, and force relaxation results in force deterioration [7].…”

3D digital analysis of tooth movement with magnets and elastics in vitro

“…concluded that 50% of elastic-force degradation occurred in the first four to 5 h of placement [ 20 ]. Several other studies also reported the large initial decrease in the force generated by elastics in orthodontics treatment [ 20 , 21 , 22 , 23 , 24 , 25 ], potentially requiring the orthodontist to change a treatment plan to include higher forces than deemed necessary [ 23 ]. To reconcile this dilemma, one study suggested that patients be instructed to change elastics twice daily to minimize relaxation [ 24 ].…”