@Article{, title={The Effect of Two Types of Separating Medium and Investment Materials on Some Physical Properties of Acrylic and Nylon Denture Base Materials}, author={Suad Jafar Alnakash and Nagham Bahjat Kamil and Farah Nabeel Mohammed Tahir Al-Khayyat}, journal={Karbala Journal of Medicine مجلة كربلاء الطبية}, volume={6}, number={2}, pages={1675-1683}, year={2013}, abstract={background: The relatively rough surface of gypsum mould may be penetrated byacrylic denture base resin and adhere to it, to prevent this, a separating medium mustbe employed.Objectives: The aim of this study is to evaluate the effect of separating medium substituteand investment materials on Surface roughness, Water sorption and solubility of acrylic andnylon denture base materials.Material and method: Two types of separating medium were chosen (Cold mold seal andglycerin). 160 specimens were prepared from heat cure and Valplast resins. Each main groupwas subdivided into four subdivisions according to the type of investment material andseparating medium used; each group of them contains 10 specimens for each test.After processing of both resins, some physical properties such as water sorption, solubilityand surface roughness have been evaluated according to investment material and comparedwith those processed using cold mold seal and glycerin.Result: In this study, the surface roughness and water solubility of both base materials aresignificantly higher when using cold mold seal than glycerin. Mean value of heat-cure acrylicresin shows high water sorption than that of Valplast. When compared by ANOVA test, thereis no significant difference between groups in both investment materials.Conclusion: The use of glycerin as a separating medium leads to smoother surfaces of bothdenture base materials, while for water sorption, neither the separating medium nor theinvestment material has an effect on it. Cold mold seal leads to higher water solubility of bothbase materials regardless of the type of investment material.

} }