Date of Graduation


Document Type


Degree Type



School of Dentistry



Committee Chair

Peter Ngan

Committee Member

Khaled Alsharif

Committee Member

Timothy Nurkiewicz


Background and Objectives

An ideal orthodontic force system should exert continuous light force. An orthodontist has the option to utilize different systems for closing orthodontic extraction space. A commonly used method when closing extraction space is to utilize orthodontic elastomeric chain. Energy Chain® (Rocky Mountain Orthodontics, Franklin, IN) allows for less deformation of shape following the initial stretch, more consistent force, and less force degradation over time. The mouth is a harsh environment that experiences daily changes in pH and temperature. These changes cause elastomeric chain to experience increased force degradation. The creation of the JUUL® (JUUL Labs, San Francisco, CA) sparked an increase in the amount of youths using e-cigarettes. Many undergo orthodontic treatment during this time. This study determines whether the presence of chemical compounds contained inside e-cigarette aerosols have an effect on the force degradation of orthodontic elastomeric chain. Additionally, force degradation was compared between elastomeric chain exposed to ambient air and exposed to a simulated oral environment.

Materials and Methods

A total of 300 elastomeric chains consisting of five links with a half link at each end were divided into three test groups. An additional 20 samples were used for initial force testing on the Instron® (Instron, Norwood, MA) electromechanical testing machine. Group 1 was a control group exposed to ambient air (AA) at room temperature, group 2 was a control group exposed to a simulated oral environment (SOE), and group 3 was an experimental group exposed to JUUL 5% Menthol e-cigarette aerosol and the simulated oral environment (SOE + E-Cig). The degradation of the elastomeric chains were tested in five time intervals: 1 day, 1 week, 2 weeks, 3 weeks, and 4 weeks. All chains were stretched and held at a distance of 32.8 mm on elastomeric jigs. E-cigarette aerosol exposure occurred five days a week and continued every day until the JUUL pod was emptied of e-liquid. An exposure device consisting of an aerosol trap, exposure chamber, flow meter, and particle sensor was used to expose the elastomeric chains. After the aerosol exposure, the elastomeric chain was placed back into the simulated oral environment. At every time interval, twenty samples were removed and placed on an Instron machine for force testing.


Significant force degradation was found among the five time intervals for all three tested groups, especially between day zero and day one. After 1 day of exposure, the force decreased from 670±0.1 g to 292.5±16.7 g in the AA group, while the SOE and SOE+E-Cig groups decreased to 249±9.7 g and 237.3±10.6 g, respectively. The average force delivered at the 4thweek for the AA, SOE, and SOE+E-Cig groups were 265.5±13.9 g, 234.6±14.7 g, and 234.0±13.2 g, respectively. The average difference in force between the AA and SOE+E-Cig group for the 4-week interval was 31.5 g (p-value of


The elastomeric chain used in this study had no statistically significant increase in force degradation when exposed to the JUUL 5% Menthol e-cigarette aerosol and the simulated oral environment over a 4-week time interval compared to the simulated oral environment alone. Energy Chain loses over 50% of its initial force over the first 24 hours of use. The amount of force degradation wasn’t enough to drop the force bellow 200 grams, therefore the Energy Chain produced slightly above the ideal amount of force to retract maxillary canines.

Embargo Reason

Publication Pending