Effect of opacifier and pigments on hardness of maxillofacial silicones.

Abstract

Objective: This study aimed to investigate the effects of an opacifier on the Shore A hardness of two pigmented maxillofacial silicones. Materials and Methods: Two commonly used maxillofacial silicones; VST-50 and LSR-05 were pigmented with 0.2% w/w yellow silicone intrinsic pigment. Kaolin powder calcined, an opacifier, was combined with the pigmented silicone in different percentage weight. Fifty-six square-shaped specimens (n=7) were divided into 6 groups, in addition to control groups, for each silicone. Each silicone was divided into three groups (0%, 5%, 10%) according to the weight of opacifier. The hardness of the specimens was investigated using a Shore A durometer. A 1-way ANOVA and Tukey’s HSD post-hoc test were performed for the Shore A hardness of VST-50 and LSR-05 at α=.05. Results: The mean Shore A hardness of VST-50 for control, 0%, 5%, and 10% groups were 32.03± 0.89, 31.22± 1.91, 30.13 ± 1.72and 27.01 ± 1.52 respectively. For LSR-05, the mean Shore A hardness were 12.97 ± 1.11, 13.03 ± 0.98, 13.14 ± 0.87 and 11.30 ± 1.11 for control, 0%, 5% and 10% groups respectively. For VST-50 and LSR-05, values of Shore A hardness were the lowest for the 10% group. The Shore A hardness decreased significantly (α =0.05) for the 10% opacifier group compared to other groups. Conclusions: LSR-05 had lower Shore A hardness than VST-50 in all groups. An addition of 10% weight of opacifier caused a significant difference on Shore A hardness of VST-50 and LSR-05 silicones.