Influence of Different Pigment Incorporation Methods on the Sorption and Solubility of Medical Silicones

Abstract

Objective The aim of this study is to verify the influence of three pigment incorporation methods (conventional, mechanical, and industrial) on the sorption and solubility of the MDX4-4210 and A-2186 silicones. Materials and Methods The groups formed were based on the silicones used (A-2186 and MDX4-4210), intrinsic pigments (pink, bronze, and black), and pigment incorporation methods (conventional, mechanical, and industrial). The dimensions of all samples were 45-mm diameter (ø) × 1-mm thickness. Readings were taken initially and after 1,008 hours of aging. Statistical Analysis Three-way analysis of variance and the Tukey’s test were performed (α = 0.05). Results For sorption and solubility, there was no difference between the incorporation methods for the A-2186 silicone, regardless of the pigment used (p > 0.05). For pink MDX4-4210, the industrial and mechanical methods showed higher values of sorption compared with the conventional method (p < 0.05). For bronze MDX4-4210, the industrial method showed a higher sorption value compared with the conventional and mechanical methods (p < 0.05). For black MDX4-4210, there was no difference between incorporation methods based on sorption (p > 0.05). For pink MDX4-4210, the mechanical method showed a higher solubility value compared with the industrial and conventional methods (p < 0.05). For black MDX4-4210 and bronze MDX4-4210, there was no statistically significant difference between incorporation methods based on solubility (p > 0.05). Conclusion Based on sorption and solubility, for the A-2186 silicone, the conventional, mechanical, and industrial methods of pigment incorporation were equivalent. For the MDX4-4210 silicone, its results of sorption and solubility were varied, and further studies are recommended.

Effect of Accelerated Aging on the Sorption and Solubility Percentages of Silicone Facial Prostheses

“…[2][3][4][5][6][7][8] The black pigment also corresponded to 0.2% of the weight of each silicone. [2][3][4][5][6][7][8] For the pink pigment, the pigments that constituted it corresponded to 0.122% (yellow), 0.006% (black), 0.03% (red), and 0.6% TiO 2 (opacifier) of the weight of each silicone. 2,[5][6][7][8] The industrial method of incorporating pigment into silicone was used.…”

“…[2][3][4][5][6][7][8] For the pink pigment, the pigments that constituted it corresponded to 0.122% (yellow), 0.006% (black), 0.03% (red), and 0.6% TiO 2 (opacifier) of the weight of each silicone. 2,[5][6][7][8] The industrial method of incorporating pigment into silicone was used. [6][7][8] In this method, the pigment and silicone were mixed by using a grinding machine (CHSG/3-Roll Mill, Chemieland, China).…”

“…2,[5][6][7][8] The industrial method of incorporating pigment into silicone was used. [6][7][8] In this method, the pigment and silicone were mixed by using a grinding machine (CHSG/3-Roll Mill, Chemieland, China). [6][7][8] Subsequently, the silicone was introduced into the metallic matrix, and it was closed and subjected to 1,000 Kgf for 10 minutes (Hydraulic press-Maxx, Essence Dental VH, Brazil).…”

“…2,8 Therefore, in the sorption process, both adsorption and absorption occur simultaneously. 2,8 Solubility is represented by the solubilization of soluble compounds of a material and the loss of these components to the environment. 2,8 A silicone prosthesis may be in frequent contact with saliva, sweat, and/or water (due to hygiene of the prosthesis…”

“…2,8,10 It is important to mention that these factors (absorption and solubility) can affect the physical, mechanical, and chemical properties of a polymer (e.g., silicone elastomer). 2,8,10 Hulterström et al reported that if a prosthesis (e.g., silicone prosthesis) absorbs liquids to the point that it loses its original dimensions or shows solubility, the prosthesis may lose its functionality and appearance. 10 Based on the fact that there are no studies in the literature reporting whether accelerated aging can have an influence on the sorption and solubility of silicone elastomers, the objective of the present study is to evaluate the effect of accelerated aging on the sorption and solubility percentages of the MDX4-4210 and A-2186 silicones.…”