Masking of temperature-induced color changes in a thermo-sensitive fiber post.
OBJECTIVE
To evaluate (1) the efficacy of the color changing technology featured by DT Light Illusion Post aimed at safely identifying the post in case of re-treatment, and (2) the efficacy of a resin composite layer to mask the post if color shift occurs due to cold food and beverages.


METHODS
Five "master disks" of 3 mm of thickness were prepared by embedding in a resin composite four thermo-sensitive posts and one translucent post (control) cut in bars. Disks of resin composite in 0.5/1.0/1.5 mm thickness were prepared as well. Digital images were taken of the master disks with and without the overlying of the resin composite disks, at 5 degrees C and at 35 degrees C temperature. By the use of Adobe Photoshop "layering function" and "multi-layer option", differences in color were calculated between the post-free and the post-containing areas.


RESULTS
The differences between the resin color and post color were remarkably higher when the temperature was 5 degrees C, showing that the technology of color change of the post was effective. With resin disk overlaid, at 35 degrees C none of the differences in color were above the threshold for clinical acceptability. At 5 degrees C blue and black colored posts were visible when the overlaid resin thickness was 0.5 mm, while at 1.0 mm and 1.5 mm none of the posts were visible.
Department of Dental Materials and Fixed Prosthodontics, Tuscan School of Dental Medicine, University of Firenze and Siena, Italy. alessandrovichi1@gmail.com
Alessandro
A
Vichi
Remo
R
Schiavetti
Edoardo
E
Pacifici
Agostino
A
Giovannetti
Cecilia
C
Goracci
Marco
M
Ferrari
D001628:Beverages; D003080:Cold Temperature; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D004853:Epoxy Resins / Q000737:chemistry*; D005502:Food; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation*; D011791:Quartz / Q000737:chemistry*; D013499:Surface Properties; D013674:Technology, Dental; D013696:Temperature; D013816:Thermodynamics
D003188:Composite Resins; D003764:Dental Materials; D004853:Epoxy Resins; D011791:Quartz