Effect of food-simulating liquids on mechanical properties and surface of a dental resin

The purpose of this study was to evaluate the effects of food-simulating liquids on the mechanical properties and surface of a dental resin. The mechanical properties considered are fatigue and flexion. Samples (n = 108) were immersed into three liquids: distilled water, citric acid and heptane. The storage time was extended to four months. However, the specimens that were not broken after 10,000 shocks were subjected to flexion. The resulting histograms showed a weak increase in the flexion resistance. Moreover, a microscopic examination made with AFM indicated a modification of the surface morphology of the samples stored in distilled water for 90 d. The citric acid presented undulations with peaks, whereas heptane had no effect compared with the intact resin.