Effect of monomer composition of polymer matrix on flexural properties of glass fi bre-reinforced orthodontic archwire

Abstract

To compare force levels obtained from glass fi bre-reinforced composite (FRC) archwires. Specifi cally, FRC wires were compared with polymer matrices having different dimethacrylate monomer compositions. FRC material (E-glass provided by Stick Tech Ltd, Turku, Finland) with continuous unidirectional glass fi bres and four different types of dimethacrylate monomer compositions for the resin matrix were tested. Cross-sectionally round FRC archwires fi tting into the 0.3 mm slot of a bracket were divided into 16 groups with six specimens in each group. Glass fi bres were impregnated by the manufacturer, and they were initially light-cured by hand light-curing unit or additionally post-cured in light-curing oven. The FRC archwire specimens were tested at 37°C according to a three-point bending test in dry and wet conditions using a span length of 10 mm and a crosshead speed of 1.0 mm/minute. The wires were loaded until fi nal failure. The data were statistically analysed using analysis of variance (ANOVA). The dry FRC archwire specimens revealed higher load values than water stored ones, regardless of the polymer matrix. A.majority of the FRC archwires showed higher load values after being post-cured. ANOVA revealed that the polymer matrix, curing method, and water storage had a signifi cant effect ( P.< 0.05) on the fl exural behaviour of the FRC archwire. Polymer matrix composition, curing method, and water storage affected the fl exural properties and thus, force level and working range which could be obtained from the FRC archwire. © The Author 2011.