초록 close

The aim of this study was to evaluate the reinforcing effect of three different fibers according to the fiber concentration on the flexural properties of orthodontic acrylic resin. The autopolymerized orthodontic acrylic resin(Orthocryl ®, Dentaurum Gmbh & Co. KG, Ispringen, Germany) was used in the study. Glass fiber (GL: ER 270FW, Hankuk Fiber Glass, Korea), polyaromatic polyamide fiber (PA: Kevlar-49, Dupont,U.S.A.), and ultra-high molecular weight polyethylene fiber (PE: P.E, Dong Yang Rope, Korea) were added to orthodontic acrylic resin. The 2.6 %, 5.3 %, and 7.9 % volume pre-impregnated fibers placed at the bottom of a specimen mold. The test specimens(n=10) of each group were stored in distilled water at 37 ± 1℃ for 50 ± 2 hours before test. The flexural strength and modulus were measured by an universal testing machine(Z020, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan's multiple range test(=0.05). In terms of flexural strength and modulus, all of the experimental groups showed significant reinforcing effects compared with the control group(P<0.05), with the exception of the 2.6 % and 5.3 % PE groups. Among all the groups, the flexural strength and modulus of the 7.9 % GL groups were the highest(P<0.05). In the same volume ratio,GL groups showed significantly higher flexural strength and modulus than the PA and PE groups at 7.9 %volume ratio(P<0.05). In the same fiber type, 7.9 % GL and PE groups showed significantly higher flexural strength and modulus than the groups of other volume ratio(P<0.05). However, there was no significant difference between the PA groups of each volume ratio(P>0.05). In this study, glass fiber at 7.9 % volume ratio showed most effective reinforcing effect on the flexural properties of orthodontic acrylic resin.