Abstract
The main characteristic of orthodontic intermaxillary elastics is the generated force. Therefore, it is necessary to know the exact properties of elastics for clinical use and their force degradation over time.
Methods: A total of 500 latex elastics of the type 3/16" Medium from the manufacturers Dentaurum, American Orthodontics, 3M, Ortho Organizers, and G&H Orthodontics were tested; 100 elastics from each. The force was measured with a force meter at time 0 and at 2, 8, 24, and 48 h.
Elastics were stored being stretched three times on a 3D-printed board in an incubator at 37 oC and under controlled humidity. Shapiro-Wilk normality tests, ANOVA tests, and Bonferroni post hoc tests were used.
Results: The mean initial force among the manufacturers ranged from 1.109 N to 1.550 N, with Dentaurum elastics being the closest to the declared force of 1.255 newton. The greatest force degradation occurred during the first two hours; the decrease in force within 24 h ranged from 20% to 33% among the manufacturers.
The maximum decrease was observed for American Orthodontics elastics. The smallest decrease occurred between 2 and 8 h for 3M, and between 24 and 48 h for Ortho Organizers.
Conclusion: Intermaxillary 3/16" Medium elastics measured in vitro differ in initial force and force degradation among individual manufacturers. The attending clinician must be aware of the basic parameters of the elastics when recommending them to patients, and measuring the initial force directly in the patient's mouth with a force meter might be helpful.