A Comparative Evaluation of Force Decay in Six Different Orthodontic Elastomeric Chains - An In-vitro Study

Abstract

Aims: Comparison of degradation of force of 6 commercially available orthodontic elastomeric chains (e-chains) for the period of 8 weeks. Settings and Design: In-vitro Study. Method and Materials: Elastomeric chains of 6 companies were stretched to a particular distance that is pre determined and comparison was made at two force magnitudes (200 gm and 350 gm) at different time points. Digital force gauge is used for measuring remaining force magnitudes at different time points. Statistical Analysis used: The comparison of difference in force decay between subgroups and effect of time on force decay was calculated using Analysis of Variance (ANOVA). Comparison of the mean force differences using paired t-test is performed from initial to final measurements. For comparison of difference of force decay of elastomeric chain products of same company, independent samples t-tests were used. Results: Maximum remained force (129.7 gm) was observed in American Orthodontics I (Ao I) subgroup followed by Ormco (Or) I (120.1 gm), Orthoorganizers (Oo) I (105.5 gm), 3m I (91.9 gm, G and H (Gh) I (80.4 gm) and Orthoclassic (Oc) I subgroup showed minimum remained force (74.9 gm) at end of 8 weeks in light force. Maximum remained force (209.0 gm) was observed in Ao II subgroup followed by Or II (191.3 gm), 3M II (188.8 gm), Oc II (129.9 gm), Oo II (121.5 gm) and Gh II subgroup showed minimum remained force (108.5 gm) at end of 8 weeks in heavy force. Conclusions: American Orthodontics showed minimum rate and Ortho Classic showed maximum rate of force decay over 8 weeks in both light force (200 gm) and heavy force (350 gm).