Viscoelastic Properties of Orthodontic Elastomers

Objectives: Our objective of this study is to find the discrepancies in elastomeric tensile strength of different brands and colors of orthodontic elastomers in differing conditions that can mimic the temperature and moisture of the oral cavity.
Methods: We created a wooden jig using wooden blocks with nails at a predetermined point. The orthodontic elastomers were tied around these blocks and placed in their respective environments. The amount of overall tensile strength was measured and recorded at varying intervals, examined over the course of a month using a tension gauge.
Results: At all time points, the percentages of tension change in dry samples were significantly lower than the ones in wet samples.
After 1 hour, 3M Silver showed the least % of change in the tension, and AO silver showed the highest % change in the tension. Although the percentage of change for AO silver was not significantly different than the one for 3M pink.
After 2 and 3 hours, the % change for RM clear was the least and 3M pink was the highest. % change for RM clear was not significantly different than 3M silver, and the % change in tension for 3M pink was not significantly different than AO silver.
For each time point from 4 hours-168 hours, the % change in the tension for RM Clear were the least and 3M Pink were the highest, bur RM Clear was not significantly different from RM silver at 6 hours.
For each time point after 336, 504 and 672 hours, the % change in tension for RM Clear were the least but it was not significantly different than RM Silver. The % change for 3M Pink were the highest, but it was not significantly different from 3M Silver and AO Silver.
Conclusions: The wet conditions, as well as the dye of different elastomeric materials cause statistically significant effects that accelerate the deterioration of the orthodontic elastomers, thus reducing the overall tensile strength. Under every time interval, there was a greater % difference in tensile strength in groups exposed to wet conditions than dry, with about a 20% difference in the 3M Silver and 3M Pink groups.