Electronic Thesis and Dissertation Repository

Thesis Format



Master of Clinical Dentistry




Tassi, Ali


Background: Intraoral Elastics have been widely used in Orthodontics for well over 100 years. Changes in material composition, manufacturing and addition of color to elastics has shown to effect force levels over time.

Aim: The purpose of the study was to determine the effect of pigmentation on force levels and their degradation over time in both Latex and Non-Latex orthodontic intraoral elastics.

Materials & Methods: Groups consisted of elastics in Latex from American Orthodontics in both natural and four different colors, American Orthodontics Non-Latex in natural, Ormco Latex in both natural and four different colors, Auradonics Latex in both natural and 4 different colors, and Auradonics Non-Latex in both natural and four different colors (25 groups total, 10 elastic samples in each group). Data collection was performed over 24-hours, at five-minute time intervals. Samples were stretched to a starting distance of 19.10mm (manufacturer recommended) and cycled with an additional 25mm at each 1-minute time interval to simulate function. A custom-built testing apparatus was utilized to simulate the intra-oral environment, and force data was collected. Latex elastics containing green pigment degraded faster and delivered lower force values, in all manufacturers, at most time points. By 12-hours, the Non-Latex elastics showed significantly lower force levels than Latex elastics. At 24-hours several of the Non-Latex elastics had failed.

Conclusions: Pigmentation and Material Composition had a significant effect on force levels and their degradation over time, with green pigment and Non-Latex elastics showing lower forcer values and greater force decay rates over time.

Summary for Lay Audience

A common concern many people have, when seeking orthodontic care, is how their teeth fit together. Orthodontic elastics are placed, by the patient, between hooks on the braces to help teeth fit together properly. These elastics come in different materials (Latex and Non-Latex) and can be supplied in both natural and a variety of colors. Elastics are supplied by different manufacturers, all of which have different manufacturing processes.

Aim of this study was to evaluate the effect of color, on force levels and force loss over time, in orthodontic elastics of different materials and manufactures.

Materials & Methods: Groups consisted of 4 different colors and 2 different elastic types from 3 different manufacturers. Groups were tested over a 24-hour time period at intervals of initial, 5 min, 30 min, 1 hour, 3 hours, 6 hours, 12 hours, and 24 hours. A custom-built testing machine was used to stretch the elastics and record the force levels. During testing, the samples were placed in an environment that simulated the conditions found in the mouth.

Results: In general, the forces delivered by all elastics decreased over time, but the decrease was larger for the Non-Latex elastic types. The Latex groups showed a more gradual and continuous decrease while maintaining a greater percentage of initial force values. Latex Elastics containing green pigment degraded faster and delivered significantly lower force values.

Conclusions: Color and elastic type, played a significant role in force delivery and their decrease over time.