Influence of food simulating solutions on the hardness of composite resins

The aim of this in vitro study was to evaluate the influence of food simulating solutions on surface hardness of three different composite resins. A total of 50 specimens were fabricated for each of Filtek Z 250, Clearfil ST, Aelite LS Packable according to the manufacturers' instructions. Ten specimens of each material were randomly selected and stored in 8% ethanol, 50% ethanol, heptane, distilled water, and air at 37 degrees C for 1 week. After one week conditioning period, hardness testing was carried out with a micro hardness tester. The hardness of composite resin materials are strongly influenced by food simulating solutions.