Room temperature Impregnation with Cold Temperature Biodur® Silicone: A Study of Viscosity.

Centre for Anatomy and Molecular Medicine, Sigmund Freud Private University, Vienna, Austria. ABSTRACT: There are two common methods for carrying out plastination with silicone polymer: coldtemperature impregnation (at -15 to -25°C) or impregnation at room temperature. The standard Biodur technique is the cold impregnation method, although some plastinators prefer to impregnate at room temperature. The aim of our study was to determine the viscosity of standard Biodur® silicone mixtures under different temperature conditions, in order to determine the optimum impregnation time. Two standard silicone mixtures were prepared: S10/S3, and S15/S3. Each silicone mixture was then divided into 3 equal parts in order to determine the viscosity at -25°C, room temperature (+20°C), and +40°C. Measurements of viscosity were carried weekly, for four weeks, using a rotary viscometer. The initial viscosity of S10/S3 at -25°C was 4 000 mPa.s, and it remained almost the same for the next 4 weeks. At room temperature, the viscosity reached 4 000 mPa.s after 4 weeks. At +40°C this value was reached after 10 days. The viscosity of the S15 mixture at -25°C increased to 455 mPa.s after one day and remained almost constant through the next 4 weeks. At room temperature the viscosity reached 400 mPa.s after 3 weeks, and at +40°C it increased to 400 mPa.s after 8 days Impregnation at room temperature is possible with both S10 and S15. For the S10 method, an impregnation period of 2 weeks would be recommended, With S15, impregnation at room temperature could be carried out over a period of 1 week, which would be possible for advanced plastinators. However, it is not recommended to plastinate nervous tissue at room temperature.