title: Color stability of glazed and polished dental porcelains.
abstract: OBJECTIVE
  The purpose of this study was to compare the visual and colorimetric color stability of two ultra low-fusing and three conventional low-fusing porcelains on both glazed and polished surfaces.
  
  
  METHODS
  Twelve disks, 10 mm in diameter and 3 mm in thickness, were fabricated for each porcelain. Specimens were glazed using their specific glaze materials. For each type of porcelain, the specimens were divided into two groups: one group was immersed in methylene blue and the other group in distilled water as a control. The surfaces were visually examined for staining without magnification. Objective color measurement was performed for each sample using a Tristimulus colorimeter. After examining the color of the glazed specimens, glazed layers were removed from the surface of the specimens to simulate an intraoral environment. Then, porcelain polishing points and diamond polishing paste were applied. The samples were immersed again in methylene blue and distilled water, and after removing from the staining solution and distilled water, visual and objective measurements were performed again.
  
  
  RESULTS
  Visually discernible stain was present on the polished groups of all five porcelains immersed in methylene blue, whereas the glazed group immersed in methylene blue showed no staining. No staining was observed with glazed and polished samples immersed in distilled water. The objective evaluation showed that the polished porcelain surface of all five porcelain products had statistically significant color deviation than the glazed surface in the same group after immersion in methylene blue. The results of this study show a statistically significant difference in color stability between the polished and glazed specimens.
  
  
  CONCLUSIONS
  It may be concluded that the glazed specimens showed a better color stability, although the staining observed in the polished specimens was not clinically noticeable.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
authors.forename: Caner
authors.initials: C
authors.lastname: Yilmaz
authors.forename: Turan
authors.initials: T
authors.lastname: Korkmaz
authors.forename: Hişam
authors.initials: H
authors.lastname: Demirköprülü
authors.forename: Gülfem
authors.initials: G
authors.lastname: Ergün
authors.forename: Yalçin
authors.initials: Y
authors.lastname: Ozkan
mesh_terms: D000704:Analysis of Variance; D003124:Colorimetry; D003764:Dental Materials / Q000737:chemistry / Q000592:standards*; D003775:Dental Polishing / Q000379:methods*; D003776:Dental Porcelain / Q000737:chemistry / Q000592:standards*; D017267:Dental Prosthesis Design; D003801:Dental Veneers; D017797:Prosthesis Coloring / Q000592:standards*; D018709:Statistics, Nonparametric; D013499:Surface Properties
chemical_list: D003764:Dental Materials; D003776:Dental Porcelain