• Wallapat Santawisuk
• Issarawan Boonsiri

Objective The purpose of this study was to compare the color stability of feldspathic porcelain, Vita Omega 900, treated with three polishing techniques and autoglazing.

Materials and methods Eighty porcelain disks were divided into four groups of twenty, one group was autoglazed and three groups were subjected to three polishing methods (Cerapol, Shofu adjustment kit and diamond polishing paste, Shofu adjustment kit and Dia Finish). The color stability was evaluated in consistence with ADA Specification No.69 for dental ceramic. Ten specimens of each group were immersed in methylene blue, and the other ten were immersed in distilled water as a controlled group. The color values (CIE L*a*b*) for each sample were recorded using a computerized spectrophotometer before and after immersion in the staining medium, and the color difference value was calculated. The surface smoothness was evaluated using scanning electron microscope (SEM). The color difference values of each group were analyzed using ANOVA.

Results It was found that the autoglazed group appeared to give the smoothest surface and the best color stability, while polishing with Shofu and Dia Finish produced a smoother surface when compared with other polishing methods. No significant differences in color deviation were found between the groups which were polished with Shofu followed by diamond polishing paste and Dia Finish.

Conclusion The color deviations of polishing with Shofu and Dia Finish were clinically acceptable. But the color deviation of those polished with Cerapol was clinically detectable. Significant difference in color deviation was also seen between the group polished with Cerapol and other groups (p<0.05).

(CU Dent J 2003;26:201-9)