Effect Of Fluoride Treatment On The Mechanical Properties Of Orthodontic Archwires - An In Vitro Study

Abstract

ABSTRACT
INTRODUCTION: Orthodontic treatment success relies on well-designed wires that
balance strength, flexibility, and range of motion. Maintaining oral hygiene is crucial during
treatment to prevent enamel demineralization and decay, exacerbated by plaque buildup
around brackets. Fluoride supplements are often recommended to mitigate these risks but
can potentially corrode orthodontic wires, leading to reduced mechanical performance and
wire fractures.
AIM & OBJECTIVES: The purpose of this study was to evaluate the effects of fluoride
treatment on the mechanical properties of four different orthodontic arch wires, namely
Nickel-Titanium (NiTi), Coaxial Superelastic Nickel-Titanium, Copper-Nickel-Titanium
(CuNiTi) and Coaxial Stainless-Steel after exposure to a predetermined time.
MATERIAL AND METHODOLOGY: 120 archwires—Nickel-Titanium (NiTi), Coaxial
Superelastic Nickel-Titanium, Copper-Nickel-Titanium (CuNiTi), and 6-Stranded Coaxial
Stainless-Steel—were tested. Pre-adjusted edgewise brackets were bonded to artificial
teeth, and wires were ligated using elastomeric ties. Archwire samples were immersed in
fluoride mouthwash and incubated, then tested for Modulus of Elasticity, Yield Strength,
and Deflection using a Universal Testing Machine.
RESULTS: All wire types showed significant reductions in mechanical properties after
fluoride exposure, with NiTi wires experiencing the most pronounced decline, and 6-
Stranded Coaxial Stainless-Steel wires demonstrating the least change.
CONCLUSION: Topical fluoride significantly diminishes the mechanical strength of
orthodontic archwires due to corrosion, compromising their effectiveness during initial
treatment phases and potentially extending treatment times.
KEYWORDS: White spot lesions, Orthodontic archwires, Fluoride, mechanical properties