Flay ash containing from metals and metal oxides can be add as a filler in resin composite to solve some problems, such as increase the strength and flexibility of resin or to improves properties, this is the aim of this project, therefore several ratios 0.0005, 0.001, and 0.0015 to prepared 40 samples, depth of cure, hardness, compressive strength, and XRD teste valuated as a physical tests, also enzyme Amylase and PH in the saliva as a biological effects of these fillers in resin composite. The results illustrated Depth of cure (mm) without fly ash and with the filler in larger ratios increase (from 2.9 to 3,7) because the addition of fly ash in a different ratio allows a large number of monomer converse where the presence of fly ash in a homogeneous manner between the primary atoms widens the interconnecting distance of the crystal lattice and thus allows light cure to perform polymerization process perfectly, Hardness in (Mpa) unit of inner (from 76.93 to 86.2), average compressive strength (Mpa), (153 to 220), XRD test show simple different in crystals structures, then both PH test and enzyme amylase activity in saliva prove nontoxically resin composite.

Flay Ash, Hardness and Compressive Strength, Resin Composite, Enzyme Amylase.