Color stability and colorant effect on maxillofacial elastomers. Part I: colorant effect on physical properties

Area of Science:

• Materials Science
• Biomaterials Engineering
• Prosthodontics

Background:

• Maxillofacial prostheses have a limited clinical lifespan of approximately 6 months.
• Prosthesis refabrication is often necessitated by the degradation of color and physical properties.

Purpose of the Study:

• To evaluate the impact of various coloring agents on the physical characteristics of maxillofacial elastomers.
• This research is the initial phase of a comprehensive three-part investigation.

Main Methods:

• Three distinct elastomers were combined with six different colorants, including dry earth pigments, rayon fiber flocking, artist's oil paints, kaolin, and liquid cosmetics.
• Physical properties such as hardness, tear strength, ultimate tensile strength, and percentage elongation were systematically measured for 180 specimens.
• Statistical analyses, including one-way ANOVA and the Student-Newman-Keuls test, were employed to identify significant differences between groups.

Main Results:

• The incorporation of coloring agents significantly modified the physical properties of the maxillofacial elastomers.
• Certain colorants, like dry earth pigments, kaolin, and rayon flocking, functioned as fillers without integrating into the silicone matrix.
• Other colorants, such as artist's oils and liquid cosmetics, behaved as liquid phases, also failing to bond with the silicone.

Conclusions:

• The study did not identify a universally superior combination of colorant and elastomer for all tested physical properties.
• The interaction between colorants and elastomers significantly influences material performance.