Effect of extraoral aging conditions on the color stability of high temperature vulcanizing and room temperature vulcanizing maxillofacial silicone elastomers: An in vitro study

Abstract

Maxillofacial prostheses require enhancement or replacement due to deterioration in their color during their use. The major factors that affect the color of the prostheses are ultraviolet (UV) light exposure, temperature changes, and cleaning and handling by the patient. The aim of the study was to find the effect of extraoral aging conditions on the color stability of high temperature vulcanizing (HTV) and room temperature vulcanizing (RTV) maxillofacial silicone elastomers. Specimens of 25mm x3mm dimensions were fabricated in Techsil S25 HTV silicone and Factor II RTV silicones and processed according to the manufacturer’s instructions. Eight groups with eleven specimens each were made. The color stability test was conducted with a Ultraviolet- visible (UV-VIS) spectrometer (Shimadzu) before and after exposure to outdoor weathering and disinfection. The results of the two groups were compared using independent t test. The results of the subgroups were compared with One way ANOVA test followed by Scheffe multiple comparison test. The average color change was found highest in subgroup 4(3.90) and least in subgroup 3(2.3) in HTV samples. The average color change was found highest in subgroup 1(2.70) and least in subgroup 2(1.78) in RTV samples. Color changes caused by HTV samples were significantly greater than that caused by RTV samples. Color changes caused in subgroups 2 and 4 between HTV and RTV samples were significantly greater than in the other groups. There were no significant differences in color change in other subgroups.