Abrasive wear of filled and unfilled resins in vitro

The present investigation was initiated to evaluate the wear resistance of filled and unfilled resins which may be suitable for fissure sealing. Two commercial unfilled resins (Adaptic Glaze and Delton), three degrees of diluted composite (Adaptic diluted with Adaptic Bonding Agent) and undiluted composite (Adaptic) were studied. Abrasion was caused by 400-grit silicon carbide paper in a mechanical surface grinder. Ten specimens of each of the material samples were tested. The unfilled resins were abraded three to six times more readily than the composite samples. Undiluted composite was the most resistant, whereas samples of increasing degrees of dilution were abraded to increasing extents. However, even the most diluted composite, although very fluid, was at least three times more resistant than the unfilled samples. The results of this study indicate that adding inorganic filler particles to a resin, even in small amounts, greatly enhances the wear resistance of such materials.