FRP Esthetic Orthodontic Wire and Development of Matrix Strengthening with Poly(methyl methacrylate)/Montmorillonite Nanocomposite

Abstract

Orthodontic treatment using a multibracket appliance is the most popular and precise method for correcting misaligned dentition. We have been working to replace a conventional orthodontic metal wire with a fiber reinforced thermo-plastic (FRP) wire and have developed an esthetic transparent FRP wire containing biocompatible glass fibers and poly (methyl methacrylate) (PMMA). However, loss of mechanical properties carried by failure related with glass fibers has not yet been resolved. Meanwhile, we are working on developing a super-fiber (high-strength and high-modulus fibers) reinforced thermo-plastic wire; for this we will have to focus on improving the stiffness of PMMA without causing any deterioration in its flexibility. Transparent PMMA/layered silicate nanocomposites were fabricated by a solution intercalation method. Montmorillonite, organically modified with quaternary alkylammonium ions, was selected as the filler for reinforcement. The nanocomposites are transparent enough for their use as esthetic orthodontic wires. The flexural modulus of them was favorably improved. Those results encourage us to make them applicable for other dental use. To the best of our knowledge, there has been little or no research on polymer/layered silicate nanocomposites in the field of dentistry. A novelty and an application potentiality of our challenge are beneficial for evolving dentistry.