Temperature-dependence of the mechanical properties of FRP orthodontic wire.
The temperature-dependence of the mechanical properties of a new esthetic orthodontic wire with fiber-reinforced plastic (FRP) structure was investigated. The new FRP wire, fabricated by a hot drawing method, is 0.5 mm in diameter and has a multiple fiber structure composed of biocompatible CaO-P2O5-SiO2-Al2O3 glass fibers of 20 microns in diameter and a polymethyl methacrylate matrix. The flexural load at a deflection of 1 mm and Young's modulus at 24, 37, and 50 degrees C under wet conditions showed similar fiber fraction dependence to those under dry conditions for a fiber fraction of 40-51%. The flexural load and Young's modulus tended to decrease slightly with increases in temperature. This tendency was larger for the lower fiber fraction. However, the difference in flexural load for a temperature difference of between 24 degrees C and 50 degrees C was at most 10 gf. This is negligibly small, and a constant orthodontic force regarding temperature change would be advantageous from a clinical point of view.
Imai
T
T
Department of Orthodontics, Hokkaido University, Sapporo, Japan.
Yamagata
S
S
Watari
F
F
Kobayashi
M
M
Nagayama
K
K
Toyoizumi
H
H
Uga
M
M
Nakamura
S
S
D004548:Elasticity; D005898:Glass / Q000737:chemistry*; D008422:Materials Testing; D009969:Orthodontic Wires; D018583:Pliability; D019904:Polymethyl Methacrylate / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
C009753:fiberglass; D014867:Water; D019904:Polymethyl Methacrylate