Reactive fibre reinforced glass ionomer cements.
The mechanical properties of glass ionomer cements used in restorative dentistry reinforced by chopped glass fibres were investigated. Reactive glass fibres with a composition in the system SiO(2)-Al(2)O(3)-CaF(2)-Na(3)AlF(6) and a thickness of 26 microm were drawn by a bushing process. The manufacturing parameters were optimized with respect to maximum strength of the glass fibre reinforced ionomer cements. Powder to liquid ratio, pre-treatment of the glass, grain size distribution and fibre volume fraction were varied. Glass fibre and cement were characterized by X-ray diffraction, transmission electron microscopy and energy dispersive spectroscopy techniques, respectively. The highest flexural strength of the reinforced cement (15.6 MPa) was found by compounding 20 vol% reactive fibres and extending the initial dry gelation period up to 30 min. Microscopic examination of the fractured cements indicated a distinct reactive layer at the fibre surface. A pronounced fibre pull out mode gives rise to an additional work-of-fracture contributed by pulling the fibres out of the fracture surface.
Policlinic for Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Glueckstrasse 11, Erlangen 91054, Germany. lohbauer@dent.uni-erlangen.de
Ulrich
U
Lohbauer
Jürgen
J
Walker
Sergej
S
Nikolaenko
Jan
J
Werner
Alexis
A
Clare
Anselm
A
Petschelt
Peter
P
Greil
D019245:Compressive Strength; D004548:Elasticity; D005898:Glass / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000138:chemical synthesis / Q000737:chemistry* / Q000145:classification; D008420:Manufactured Materials; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D005899:Glass Ionomer Cements; C009753:fiberglass