Effect of glass filler content on hydrophilic addition silicone impression materials in dentistry

Dental impression materials are used to register or reproduce the form and relationship of the teeth and oral tissues. They should not be torn when removing from the wet mouth after setting. Nowadays, silica is widely used as filler to overcome the low mechanical strength of the dental impression materials. The purpose of this study was to synthesize high strength glass in the system of MgO-CaO-Al₂O₃-SiO₂ and investigate its usefulness according to ISO standard after mixing with addition silicone. Commercial products, Contrast, Examix, Express, and Perfect-F were selected as control group. When the prepared glass filler was introduced in addition silicone impression material, tear strength was drastically increased significantly than that of the control group, keeping the consistency. All experimental groups showed higher tear stength than that of control groups. As the amount of filler content increases, tear strength was increased. Strain in compression, recovery from deformation, and linear dimensional change were satisfied the ISO standard either all the experimental or control groups. Therefore, calcium-substituted magnesium aluminosilicate glass in the system of 12.5MgO-17.5CaO-20Al₂O₃-50SiO₂ is expected the useful filler in the light body of addition silicone impression materials.