A1 Journal article – refereed
Mechanical properties and fracture behavior of flowable fiber reinforced composite restorations




List of Authors: Lippo Lassila, Filip Keulemans, Eija Säilynoja, Pekka K.Vallittu, Sufyan Garoushi
Publisher: Elsevier Inc.
Publication year: 2018
Journal: Dental Materials
Journal name in source: Dental Materials
Volume number: 34
Issue number: 4
ISSN: 0109-5641

Abstract

Objective

The
aim was to evaluate the effect of short glass-fiber/filler particles
proportion on fracture toughness (FT) and flexural strength (FS) of an
experimental flowable fiber-reinforced composite (Exp-SFRC) with two methacrylate
resin formulations. In addition, we wanted to investigate how the
fracture-behavior of composite restorations affected by FT values of
SFRC-substructure.

Methods

Exp-SFRC was prepared by mixing 50 wt% of dimethacrylate based resin matrix (bisGMA or UDMA based) to 50 wt% of various weight fractions of glass-fiber/particulate filler (0:50, 10:40, 20:30, 30:20, 40:10, 50:0 wt%, respectively). FT and FS were determined for each experimental material following standards. Specimens (n = 8) were dry stored (37 °C for 2 days) before they were tested. Four groups of posterior composite crowns (n = 6)
composed of different Exp-SFRCs as substructure and surface layer of
commercial particulate filler composite were fabricated. Crowns were
statically loaded until fracture. Failure modes were visually examined.
The results were statistically analysed using ANOVA followed by post hoc
Tukey’s test.

Results

ANOVA revealed that ratio of glass-fiber/particulate filler had significant effect (p < 0.05) on tested mechanical properties of the Exp-SFRC with both monomer systems. Exp-SFRC (50 wt%) had significantly higher FT (2.6 MPam1/2) and FS (175.5 MPa) (p < 0.05) compared to non-reinforced material (1.3 MPam1/2, 123 MPa).
Failure mode analysis of crown restorations revealed that FT value of
the substructure directly influenced the failure mode.

Significance

This study shows that short glass-fibers can significantly reinforce flowable composite resin and the FT value of SFRC-substructure has prior importance, as it influences the crack arresting mechanism.


Last updated on 2019-21-08 at 20:47