Silane treatment effects on glass/resin interfacial shear strengths.
OBJECTIVE
Methacrylic resin-based dental composites normally use a bifunctional silane coupling agent with an intermediary carbon connecting segment to provide the interfacial phase that holds together the organic polymer matrix with the reinforcing inorganic phase. In this study, fiber pull-out tests were used to measure the interfacial bond strength at the fiber-matrix interface.


METHODS
Glass fibers (approximately 30 microm diameter, 8 x 10 (-2)m length, MoSci) were silanated using various concentrations (1, 5 and 10%) of either 3-methacryloxypropyl-trimethoxysilane (MPS) or glycidoxypropyltrimethoxy-silane (GPS) in acetone (99.8%). Rubber (poly(butadiene/acrylonitrile), amine terminated, M(w) 5500) molecules were also attached to the fiber surface via GPS molecules. The resin was comprised of a 60/40 mixture of Bis-phenol-A bis-(2-hydroxypropyl)-methacrylate (BisGMA) and tri (ethylene glycol) dimethacrylate (TEGDMA). A bead of resin approximately 2-4 x 10(-3)m in embedded length was placed on the treated fibers and light cured. The load required to pull the fiber out of the resin was converted to shear bond strength.


RESULTS
Interfacial shear strengths were greater for silanated specimens compared with unsilanated, and for MPS compared with GPS. The same set of samples soaked in 50:50 (v/v) mixtures of ethanol and distilled water for a period of 1 month showed a decrease in properties.


CONCLUSIONS
A positive correlation was found between the amount of silane on the filler surface and the property loss after soaking. Rubber treatment provided improvement in interfacial strength. 5% MPS samples had the highest strength both in soaked as well as unsoaked samples.
Department of Chemistry, Temple University, Philadelphia, PA 19122, USA.
Subir
S
Debnath
Stephanie L
SL
Wunder
John I
JI
McCool
George R
GR
Baran
D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D003799:Dental Stress Analysis; D005898:Glass; D008422:Materials Testing; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D012408:Rubber; D033081:Shear Strength; D012821:Silanes
D003188:Composite Resins; D011109:Polymethacrylic Acids; D012821:Silanes; C009753:fiberglass; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D012408:Rubber