Comparison of 4 Brands of Elastomeric Chains Based On Time Dependent Force Decay

Objectives: To compare the force decay rate of the four brands of elastomeric chain over time and finally establish a gradation of brands in terms of force degradation characteristics. Materials and Methods: In this study total of two hundred and forty elastics were used. It had elastics of the same size from four different manufacturers. The experiment was carried out in vivo. For each patient the interbracket distance is measured for all four quadrants.The total distance thus registerd is then divided into half and recorded for effective chain length to standardize the amount of stretch for each chain. Four brands of elastomeric chain then attached to the specific attachment in patients mouth using split mouth technique. The patient recalled and the sample collected at 24 th hour,after 10days of following the first sample collection,and 30 days after the second sample collection.One set of sample of specified length was collected at 0 hours at not stretched condition. The procedure is repeated for all the 15 patients.A total of 240 samples thus collected using the following method. An Instron universal testing machine was used to measure the force in newton exerted by the elastics. Results: The result reveals at 24 hours there is a massive loss of initial exerted force and for all the brands the loss of force ranged from 35-40%.At this specific time the brand that retains maximum amount of initial force is Plastic chain(AO) at the level of 63.48% while maximum degradation of force was found in ALASTIK(3M UNITEK) which retained only 59.92%.At 10 days maximum force retained by ALASTIK(3M UNITEK) at 51.83% while maximum degradation was found in Plastic chain(AO) with only 46.23%.At the end of 30 days the effective loss of initially expressed force appears to be almost at the same level of all the commercially available brands.However the study reveals the leading brand in maximum force retention was DYNA-LINK(G&H) which retained 40.8% while Plastic chain(AO) was found to have lost the maximum force and retained only 39.63%. Conclusions: The conclusion suggests Plastic chain(AO) retains the highest amount of its initial force in percentage at the end of 24 hours but Between the time period of 24 hours and 10 days ALASTIK(3M UNITEK) loses the minimum amount of force in percentage among all brands.However it is DYNA-LINK(G&H) which showed the highest amount of retained average force compared to its initial force in percentage and exhibited a degradation performance which is more stable than the other brands.