The effect of thixotropic agent on the mechanical properties of maxillo-facial silicone materials

Extraoral maxillofacial prosthetics is the state of art and science restoring missing and/or defective facial tissues resulting from cancer surgery, accidental or congenital deformities. The success of the prosthesis depends on the size and localisation of the defect, experience of the maxillofacial prosthodontist or anaplastologist, and the properties of the materials used.Besides many properties, the maxillofacial prosthetic materials should have high tear and tensile strengths, hardness similar to the tissues being replaced, and a reasonable level of viscosity to make manipulation of the uncured material convenient.In fabrication of maxillo-facial prosthesis, thixotropic agents is added to the uncured silicone before moulding for easy manupulation and colouring. The amount of thixo added to the uncured silicone elastomers is regulated by the operator entirely. One to two drops of thixotropic agent is recommended for many platinum-based silicone elastomers by the manufacturers. Due to the different viscosity of the silicone elastomers, thixotropic agent may affect the silicone products differently. In addition, there is no research reported on the effect of the thixotropic agent on the physical properties of silicone maxillofacial elastomers.The purpose of this study was to determine the effect of different amount of thixotropic agent on the physical properties of three different platinum silicone elastomers.Key Words: Congenital Deformity, Viscosity, Thixotropic Agent