ABSTRACT
This investigation was carried out to study the effect of incorporating different percentages of glass fibers on transverse strength, modulus of elasticity, deflection, and toughness of heat-cured and autopolymerizing acrylic denture base materials. Different percentages of loose, random and short cut glass fibers [0%,1%,2%,3%,5% and 10%] were incorporated into acrylic denture base resins. The results showed that the incorporation of 1% of glass fibers into the heat-cured acrylic resin increased transverse strength by some 31 percent. While the addition of 2% of glass fibers increased the transverse strength of the autopolymerizing acrylic resin by some 40 percent. The incorporation of more than 3% glass fibers into both types of acrylic resin had no significant effects on the transverse strength, modulus of elasticity, defection and toughness of both tasted materials [p>0.05]. The glass fibers had better effects on autopolymerizing acrylic resin rather than on heat-cured acrylic resin