Force levels of fiber-reinforced composites and orthodontic stainless steel wires: a 3-point bending
March 16th, 2008 | by admin |Force levels of fiber-reinforced composites and orthodontic stainless steel wires: a 3-point bending test.
INTRODUCTION: The purpose of this study was to evaluate the force levels of 2 sizes (diameters, 0.6 and 1.2 mm) of fiber-reinforced composites (FRCs) (Ever Stick; Stick Teck Ltd, Turku, Finland) compared with orthodontic stainless steel wires (sections, 0.016, 0.018, 0.017 x 0.025, and 0.019 x 0.026 in) under the same testing conditions. METHODS: The samples were divided into 12 groups, each consisting of 10 specimens. Each sample was evaluated with a 3-point bending test on a universal testing machine. The FRC groups were light-cured by hand with a halogen curing unit (Optilux 501; SDS Kerr, Danbury, Conn) for 40 seconds. Groups 1 through 6 were tested at 1-mm deflection, and groups 7 through 12 at 2-mm deflection. RESULTS: The results of ANOVA indicated significant differences among the various groups (P = .000). The post-hoc test showed that the 2-mm deflection groups had significantly higher load values than the 1-mm deflection groups (P = .000). The highest force levels were recorded with the 1.2-mm FRCs, followed by the 0.019 x 0.026-in stainless steel wires. No significant differences were found between the 0.6-mm FRCs and the 0.017 x 0.025-in wires. The lowest load values were reported with the 0.016-in stainless steel wires. CONCLUSIONS: The 1.2-mm FRCs showed higher load values than the other stainless steel wires and the FRCs, whereas no significant difference was found between the 0.6-mm FRCs and the 0.017 x 0.025-in stainless steel wires. Thus, FRCs can be considered a viable esthetic alternative to full-size stainless steel wires to rigidly join dental segments to form anchorage units or units for active tooth movement.
Cacciafesta V, Sfondrini MF, Lena A, Scribante A, Vallittu PK, Lassila LV.
Department of Orthodontics, University of Pavia, Pavia, Italy. vcacciafesta@hotmail.com