Composite resins with a condensable inorganic phase

Reinforcing filler particles with open porosity can be prepared in three-dimensional networks made from extremely fine sintered glass fibers. Such fillers can be impregnated with a monomer, used for a putty type of composite, or packed into close particle contact by the use of a condensation technique similar to that used with dental amalgam. The condensation technique allows the use of high viscosity liquid resins and need not be accompanied by an increased amount of internal air voids. Condensed composite resins can be made which have a high finishability after curing.