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The aim of this study was to assess the force degradation of different types of elastomeric orthodontic chains subjected to tensile strength during different periods of time in artificial saliva at 37°C. A total of 312 elastomeric chains were evaluated. Six different types were studied: transparent extra-straight (TXS), transparent straight (TS), transparent wide (TW), gray extra-straight (GXS), gray straight (GS), and gray wide (GW) chains. Forty-eight different groups were made, six as controls. The remaining 42 groups were subjected to tension until initial length doubled in varying periods of time (1, 3, 24, 96, 160, 360, and 720 h). The tensile strength was measured using an Instron machine. Our results showed that most of the loss in strength occurred during the first hour (50.72% for TXS chains, 30.80% for TS chains, 64.51% for TW chains, 41.57% for GXS chains, 29.99% for GS chains, and 25.32% for GW chains) and reached a maximum peak at 4 days. This was followed by a recovery during the remainder of the experimental period. Gray chains demonstrated less force decay when compared with transparent chains. Our conclusions were that loss of strength depends on time, thickness of the elastic chains, and distance between the links. These findings might serve as a practical guideline for the clinician. |
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