In vitro study of the force degradation of latex orthodontic elastics under dynamic conditions

Alexandre MORIS, Kikuo SATO, Adriano Francisco de Lucca FACHOLLI, José Euclides NASCIMENTO, Fábio Ricardo Loureiro SATO

Aim: To analyze 3 sizes of latex orthodontics elastics (1/8”, 3/16” and 5/16”), all classifi ed as heavy force by their manufacturers, of the following commercial brands: Dental Morelli, 3M Unitek Corporation and American Orthodontics. Methods: Through a developed device, the elastics bands were distended 26mm (position of rest of the mandible) and submerged in artifi cial saliva to 37ºC. Every minute they were prolonged to 44mm (simulation of mandibular movements) and after 1 second they returned to 26mm. Measurements were accomplished in intervals of varied times. In the periods considered as meals time (3 times a day), the elastics bands were removed of the device and kept in an acrylic box, and in the period considered as nocturne the pneumatic device was turned off and the elastics bands were stretched in 26mm. Results: The larger force degradation happened in the fi rst 2 hours for the whole sample. Conclusion: the elastics bands presented signifi cant statistic differences in relation to thickness and width; and the 1/8” elastics bands should be changed at least every 24 hours and the 3/16” and 5/16” elastic bands can be changed every 72 hours, if force levels similar to the initials are desired.

Keywords: Orthodontics. Elastic. Latex. Degradation. Force.

Saturday, November 23, 2024 09:42