The aim is to evaluate the flexural strength of
acrylic resin bars depending on the addiction of glass fibers with or without previous 3-methacryloxypropyl-trimethoxysilane
(silane) application. Short fibers (3 mm) were treated and added to an acrylic resin powder, being further mixed with
acrylic liquid to create bars (25 × 2 × 2 mm) of 11
experimental groups (N = 10), according to the interaction of experimental
factors: weight % of glass fibers: (0.5; 1; 3; 4; 6 and 7) and silane
application (with silane (S) or without silane (N)). Flexural strength and scanning microscopy evaluation were performed
(SEM). Data (MPa) were submitted to ANOVA and Tukey (α = 5%). A
significant difference between groups was observed (p = 0.001): S7%(128.85 ± 35.76)a,
S6% (119.31 ± 11.97)ab, S4% (116.98 ± 25.23)ab, N4% (107.85 ± 24.88)abc, S1%
(96.29 ± 20.65)bc, S0.5% (89.29 ± 7.33)cd, S3% (89.0 ± 11.27)cd, N3% (86.79 ± 17.63)cd,
N1% (85.43 ± 16.44)cd, Control (73.29 ± 25.0)de, N0.5% (59.58 ± 19.46)e. For N
groups, it was not
possible to include more than 4%wt fibers. SEM showed better fiber-resin
interaction for S groups, and fractures around fibers on N groups. Previous
silane application enables the addiction of greater quantity of glass fibers
and better interaction with the acrylic resin resulting in higher flexural
strength. Without silane, fibers seem to act as initial crack points due to
poor interaction.