The purpose of this study was to evaluate the in vitro effect of Light Coke™, phosphoric acid, and citric acid on the force decline pattern of two types of elastomeric chains.

One hundred sixty gray colored elastomeric chain modules, 80 Chainette (GAC) and 80 Sunburst™ (GAC) chains, were divided into four groups for immersion into Light Coke, phosphoric acid, citric acid, and artificial saliva. The initial stretched force of the elastomeric chains ranged from 220gf to 250gf. During the experiment, all elastomeric chains were kept immersed in artificial saliva at 37°C (pH≈6.24) to simulate the oral environment. To simulate daily consumption of Light Coke, the elastomeric chains were immersed in the solutions twice a day for 15 minutes. The control group was kept immersed in artificial saliva continuously with no further treatment. Force (gf) was measured with a Dial-Type dynamometer (Dentaurum^®), initially (baseline), 24 hours, 7, 14, and 21 days. Data were analyzed using the Tukey test at a 5% level of probability.

A statistically significant reduction on the force produced by the elastomeric chains was seen at different time points. The greatest reduction in force occurred in the first 24 hours (p=0.01).

Force decay of the Chainette elastomeric chains were lower than the Sunburst™ chain (p<0.05). The immersion treatments caused no statistically significant difference in force for either chain module (p>0.05).

Good elastomeric chain properties are necessary for effective tooth movement, and knowledge of force-decay rates is an important factor in achieving the best orthodontic outcome.

Teixeira L, Pereira BP, Bortoly TG, Brancher JA, Tanaka OM, Guariza-Filho O. The Environmental Influence of Light Coke™, Phosphoric Acid, and Citric Acid on Elastomeric Chains. J Contemp Dent Pract 2008 November; (9)7:017-024.