Effect of short glass fiber/filler particle proportion on flexural and diametral tensile strength of a novel fiber-reinforced composite  Rodrigo Borges Fonseca, DDS, Ms, PhD, Letícia Nunes de Almeida, DDS, Gustavo Adolfo Martins Mendes, DDS, Amanda Vessoni Barbosa Kasuya, DDS, Ms, Isabella Negro Favarão, DDS, Ms, Marcella Silva de Paula, DDS  Journal of Prosthodontic Research  Volume 60, Issue 1, Pages 47-53 (January 2016) DOI: 10.1016/j.jpor.2015.10.004 Copyright © 2015 Japan Prosthodontic Society Terms and Conditions

Fig. 1 Diametral tensile strength results (mean±standard deviation, MPa). Statistical comparisons by ANOVA and Tukey tests (α=0.05). Journal of Prosthodontic Research 2016 60, 47-53DOI: (10.1016/j.jpor.2015.10.004) Copyright © 2015 Japan Prosthodontic Society Terms and Conditions

Fig. 2 Flexural strength results (mean±standard deviation, MPa). Statistical comparisons by ANOVA and Tukey tests (α=0.05). Journal of Prosthodontic Research 2016 60, 47-53DOI: (10.1016/j.jpor.2015.10.004) Copyright © 2015 Japan Prosthodontic Society Terms and Conditions

Fig. 3 SEM analysis of crack propagation and fiber distribution. (A) ×40 magnification, F22.5/P55 group showing irregular distribution of fibers and presence of bubbles in the resin. (B) ×400 magnification, F22.5/P55 group exhibiting areas without reinforcement and air bubble entrapment resulting in stress concentration regions with crack propagation. The bubble, at the upper right side of this figure probably started the crack propagation (white arrows). (C) ×40 magnification, F30/P47.5 group showing more quantity of fiber reinforcement all over the specimen. (D) ×400 magnification, F30/P47.5 group presenting more amount of fibers with closer interaction of fiber/resin matrix, without empty spaces for crack propagation. Journal of Prosthodontic Research 2016 60, 47-53DOI: (10.1016/j.jpor.2015.10.004) Copyright © 2015 Japan Prosthodontic Society Terms and Conditions

Fig. 4 SEM fractographic analysis of the interaction between fibers and resin (F30/P47.5 group). (A) ×450 magnification, remnants of resin adhered to the fiber surface after fracture, showing strong adhesion. (B) ×1000 magnification, evidence of effective fiber reinforcement since a multiplane crack growth took place, with fibers showing different fracture modes (white arrows) and still are well adhered to the resin. (C) ×3500 magnification, the white arrow indicate a semi elliptical site of fracture initiation and black arrows shows the fiber well adhered to the resin. Journal of Prosthodontic Research 2016 60, 47-53DOI: (10.1016/j.jpor.2015.10.004) Copyright © 2015 Japan Prosthodontic Society Terms and Conditions