Noor M. Shihab, Faiza M. Abdul-Ameer
Abstract: Background Silicone advantageous properties made it to become the material of choice in construction of maxillofacial prosthesis but its properties may change after addition of pigments and usage. This study aimed to define the optimum concentration of 2 types of intrinsic pigments that added to VST-50 silicone and study their effects on tensile strength and percentage of elongation before and after aging. Materials and methods According to the pilot study, 0.1 % of rayon flocking and 0. 2 % of burnt sienna intrinsic pigments concentrations were selected because of improvement in tested mechanical properties of VST-50 silicone. Sixty samples were prepared in order to measure (tensile strength and percentage of elongation) before and after aging and divided into 6 subgroups with 10 samples made for each one of these sub groups. After that the samples are tested before and after (75 and 150 hrs.) of aging and the data were analyzed with a descriptive statistical analysis, student t-test and one -way ANOVA test. Results The results for pigmented samples before aging show that tensile strength had improved while percentage of elongation was decreased. After (75 and 150) hours of aging, percentage of elongation highly significantly decreased while tensile strength had highly significantly decreased. Conclusion The addition of intrinsic pigments had improved tensile strength of maxillofacial silicone which was on the reverse for percentage of elongation. After subjecting the maxillofacial silicone to aging, both had been adversely affected.
Keywords: aging, tensile strength, intrinsic pigments, maxillofacial silicone, percentage on elongation