a thickness of 0.2 mm and 0.5 mm, respectively. Siliconerubber (M511 Maxillofacial Silicone System, Technovent Ltd., SouthWales, UK) for facial prostheses was used to prepare 60x60x1.5 mmsheets as described previously (Ariani et al., 2015). All polymers werecut into pieces of 10x10 mm. In addition, 10x10 mm glass slides with athickness of 1 mm were used. The materials were sterilized with 70%ethanol and dried under sterile conditions in a laminar airflow hood.