the effect of surface coating on softness of two kinds of tissue conditioners

introduction one of the limitations of tissue conditioners (tc) is gradual hardening of the material in a short time period after insertion in the mouth, due to the loss of their viscoelastic properties. the aim of this study was to determine the softness of two different tissue conditioners with and without the monopoly coating. methods and materials in this experimental study, acropars and viscogel tissue conditioners were examined. ten samples of each tissue conditioner were prepared, using 3×20 mm (h×d) aluminum cylindrical molds. half of the samples in each group were coated with monopoly coating. samples were kept in a water bath at 37ºc and the hardness of their surfaces was measured (in shore-a) after 1, 3, 7, 14, and 28 days. the results were analyzed using t-test, multivariant anova and tucky posthoc test. results there were significant differences in hardness (p < 0.05), comparing, the coated and uncoated acropars (p=0.000), the coated and uncoated viscogel (p=0.000), the coated acropars and uncoated viscogel (p=0.000), the coated acropars and coated viscogel (p=0.036), and the uncoated acropars and coated viscogel (p=0.000) samples. discussion it was found that the hardness of all of the samples increased with time. for both tissue conditioners, the hardness of samples with coating was higher than of those without coating. this indicates that the monopoly coating dose not protect the softness of these two tissue conditioners. key words tissue conditioner, coating, monopoly, softness.