Effect of Toothpaste on Tensile Strength of Orthodontic Elastomeric Chains

Objectives: Fluoride and peroxide ions have strong oxidative properties. It is hypothesized that fluoride- and peroxide-containing toothpastes will produce greater degradations in tensile strength of elastomeric chains than products without those components. The objective of this study is to compare the tensile strengths of selected elastomeric chains after twice-daily immersions in four toothpastes for 4 days.
Methods: Four grey closed-loop products were tested: Dentsply GAC Silver Super Elastic Chain (GAC), RMO Energy Chain (RMO), Ormco Generation II Power Chain (ORM), and 3M Unitek Alastik Chain (3MU). Five specimens per group were immersed twice daily (15min/immersion) in 200 mL of water (control; CTL) or in 200 mL water containing 125g of Aquafresh Cavity Protection (AQC), Colgate Optic White (COW), Arm and Hammer Peroxicare (AHP), or Tom’s of Maine Fluoride Free (TOM) toothpastes. Specimens were rinsed after immersions, and stored in water (37±1°C) between immersions. Initial (F0), 1-day (F1) and 4-day (F4) tensile forces (Newtons) were measured at an extension of 3x original length, as per the protocol described in ANSI/ADA Specification No. 105 (2010). Data were statistically analyzed using multivariate ANOVA and post hoc Tukey tests (α=0.05).
Results: Significant product*time and environment*time interactions were observed for change in force over time (Figures 1-2).
Conclusions: All of the elastomeric chain products tested showed significant decreases in mean tensile strength between initial (F0) and 4-day (F4) measurements after exposure to the various toothpastes. Significant decreases in tensile strength were also observed in products after 1 day (F1). Decrease in mean tensile strength differed based upon the composition of toothpaste and duration of exposure, but was not specific to fluoride- or peroxide-containing toothpastes.