Affiliations: [a] Department of Biomaterials Science, Institute of Dentistry, University of Turku, Turku, Finland | [b] City of Kotka Municipal Health Centre, Kotka, Finland | [c] Turku Clinical Biomaterials Centre – TCBC, Turku, Finland | [d] Stick Tech Ltd – GC Group, Turku, Finland | [e] Department of Oral Development and Orthodontics, Institute of Dentistry, University of Turku, Turku, Finland | [f] Oral Health Care, Turku Welfare Division, City of Turku, Finland
Corresponding author: Jaana Ohtonen, Institute of Dentistry, Lemminkäisenkatu 2, FI-20520 Turku, Finland. Tel.: +358504679343. E-mail: [email protected].
Abstract: The aim of this study was to investigate the mechanical properties of fiber reinforced composite (FRC) wires with different polymer matrices and compare them with steel wires commonly used in orthodontic retention. Eight groups of the FRC wires (continuous unidirectional E-glass) and a control group of steel metal Penta One 0.0215′′ were tested with a 3-point bending test. The FRC wire groups consisted of two thicknesses of fiber rovings (300-tex and 600-tex) which were impregnated with a light-curing monomer resin system of bis-GMA/PMMA or bis-Mepp/dimetacrylate/prosphoric ester monomer. The bending was continued until breakage of the specimen or to the strain of 3 mm using a span length of 10 mm and cross-head speed 1.00 mm/minute. The data were analysed using analysis of variance (ANOVA). The maximum load values of the FRC wire groups varied between 1.3 and 20.0 N, and the control group was 2.4 N. Specimens of 600-tex groups had considerably higher load values than 300-tex groups. The load value of the control steel group was close to the load value of in the 300-tex groups. Bis-GMA/PMMA impregnated FRC demonstrated higher values of maximum load than bis-Mepp/dimethacrylate/prosphoric ester monomere resin impregnated FRC.