A comparative study of flexural strength using two composite resins fiber reinforced

The purpose of this study was to evaluate the mechanical pro- perties of two composite resins Charisma (Hereaus Kulzer) and Permalute (Ultradent Products Inc.) and hence to verify the influence of a fibber addition Ribbond (Ribbond Inc.) in the flexural strength of such composite resins. Fifty-two pat- terns were prepared in a stainless steel template with a rec- tangular base in which another stainless-steel plate with nine milled spaces, measuring 15 mm length; 2 mm width and 1 mm thickness, was screwed. The patterns were divided in four groups (n=13). For Group I only Charisma; Group II Cha- risma + Ribbond; Group III only Permalute and Group IV Permalute + Ribbond. To all samples the three-point com- pression test in a MTS 810 apparatus was applied. The flexu- ral strength until rupture was obtained and SEM analysed. Data was submitted to the non-parametric 1-way ANOVA, and Tukey test (5%). Afterwards the Levene test was applied at 5% value. The results showed that Group I obtained the mean value of 164,71 MPa (mean-SD = 21,49%); for Group II 292,28 MPa (mean-SD = 34,24%); for Group III 106,50 MPa (mean-SD 24,02%) and for Group IV 61,70 MPa (mean-SD = 24,92%). The results showed that the interlocked fibers adds greater resistance to the set, being better for Charisma+Ribbond followed by Permalute+Ribbond. The M.E.V. analysis showed, however, that no chemical bond occurred between the fibers and the composite resins.