Effect of Nano-Titanium Dioxide on the Color Stability and Mechanical Properties of Factor II A-103 Compare with Multisil-Epithetics Maxillofacial Silicone Elastomer

Abstract

The objectives of this study were to evaluate the effects of nano-titanium dioxide on the color stability of pigmented silicone Factor II A-103 maxillofacial prosthetic elastomers compare with Multisil- Epithetics before and after artificial aging and to evaluate physical properties. Fifty disc-shaped maxillofacial silicone elastomer specimens in each group were fabricated for color stability evaluation. The first group was fabricated from Factor II A-103 with 2% wt nano-titanium dioxide, the second group was fabricated from Factor II A-103 without 2% wt nano-titanium dioxide and the last group was fabricated from Multisil-Epithetics. The first and the second group were colored with intrinsic silicone pigment for the same color like Multisil-Epithetics. Total of 150 specimens were aged in an artificial aging chamber (Q-Sun xenon test chamber LX 5050, USA) for 600 hrs. Color changes (ΔE*) were calculated based on the recorded CIElab values using spectrophotometer (HunterLab, ColorQuest ® XE, USA) at base line (0 hour) and then every 100 hours up to 600 hours of aging. For the physical properties test 16 dumbbell-shaped and 16 trouser-shaped of each group were fabricated and tested for tensile strength, percentage elongation and tear strength in a universal testing machine. Kruskal-Wallis was performed for analyze the differences among group at 95% confidence level and Friedman’s two way ANOVA was used to compare mean ΔE* value of each group in each time period (100-600 hrs.). For color stability test, Multisil-Epithetics exhibited smallest color changes (ΔE*=3.67) followed by Factor II A-103 with 2% wt nano-titanium dioxide (ΔE*=10.8) and Factor II A-103 without 2% wt nano-titanium dioxide (ΔE*=11.03) respectively. Multisil-Epithetics had statistically significant differences in comparison to the other groups (p<0.001). Delta-E values of all groups after 600 hours aging was higher than acceptable threshold (ΔE*=3.3).  For mechanical properties test, Factor II A-103 with 2% wt nano-titanium dioxide demonstrated significantly higher tensile strength, percentage elongation and tear strength than Multisil-Epithetics (P<0.001).  There was no significant difference of tensile strength, percentage elongation and tear strength between Factor II A-103 with and without 2% wt nano-titanium dioxide. In conclusions, incorporation of nano-titanium dioxide improved the color stability of Factor II A-103 silicone elastomer in 300 hrs. from artificial aging, but did not improve the color stability in the long term and did not improve the physical properties of the material.