Color stability and colorant effect on maxillofacial elastomers. Part I: colorant effect on physical properties.
BACKGROUND
The average clinical life span of a maxillofacial prosthesis is approximately 6 months, at which point it needs to be refabricated, mainly because of degradation of the color and physical properties of the prosthesis.


OBJECTIVE
This first part of a 3-part study evaluated the effect of coloring agents on the physical properties of maxillofacial elastomers.


METHODS
Five dumbbell-shaped and 5 trouser-shaped specimens were fabricated for each of the combinations of the 3 elastomers (Silastic medical adhesive type A, Silastic 4-4210, and Silicone A-2186) and 6 colorants (dry earth pigments, rayon fiber flocking, artist's oil paints, kaolin, liquid cosmetics, and no-colorants), for a total of 180 specimens. Evaluations of hardness and tear strength were made with the trouser-shaped specimens. Evaluations of the ultimate tensile strength and the percentage elongation were made with the dumbbell-shaped specimens. A within elastomer analysis compared the 6 colorants using a 1-way analysis of variance for each of the 4 physical properties. When significant differences were observed, the Student-Newman-Keuls multiple range test was used to identify differences between groups at a significance level of.05.


RESULTS
Physical properties of maxillofacial elastomers were changed by the incorporation of coloring agents. Dry earth pigments, kaolin, and rayon flocking acted as a solid filler without bonding to the Silicone, and artists' oils and liquid cosmetics acted as a liquid phase without bonding to the silicone matrix.


CONCLUSIONS
No clearly superior colorant-elastomer combination was demonstrated in all the tests in this study.
Haug
S P
SP
Indiana University School of Dentistry, Indianapolis, Ind. 46202, USA. SPHAUG@IUSD.IUPUI.EDU
Andres
C J
CJ
Moore
B K
BK
D000704:Analysis of Variance; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004396:Coloring Agents / Q000737:chemistry*; D004347:Drug Interactions; D004355:Drug Stability; D006245:Hardness Tests / Q000379:methods; D006801:Humans; D008422:Materials Testing / Q000379:methods / Q000706:statistics & numerical data; D008447:Maxillofacial Prosthesis / Q000706:statistics & numerical data; D017797:Prosthesis Coloring / Q000706:statistics & numerical data; D011474:Prosthesis Design / Q000379:methods / Q000706:statistics & numerical data; D012826:Silicone Elastomers / Q000737:chemistry*; D013718:Tensile Strength
D004396:Coloring Agents; D012826:Silicone Elastomers