title: Effect of accelerated aging on the color stability of feldspathic ceramic treated with various surface treatments.
abstract: OBJECTIVE
  To investigate the effect of the accelerated aging process on the color stability of feldspathic ceramic treated with dual ion exchange, overglaze, polishing, and autoglaze surface treatments.
  
  
  METHODS
  A total of 40 disks (15 mm in diameter and 2 mm thick) of feldspathic ceramic were made in an A2 shade according to the manufacturer's recommendations. The samples were randomly divided into 4 groups: dual ion exchange, overglaze, polishing, and autoglaze. The samples were subjected to conditions in an accelerated aging machine for 150 and 300 hours. Differences in color before and after accelerated aging were calculated using spectrophotometric analyses. Overall color difference (DeltaE) was determined using the CIE L*a*b* system for measuring small color differences. Scanning electron microscopy was used to evaluate the surface texture of samples. Color difference data were evaluated statistically by Kruskal-Wallis and Mann-Whitney U tests, with a significance level of .05.
  
  
  RESULTS
  After 150 and 300 hours of accelerated aging, color changes of the 4 surface treatment groups ranged between 0.35 and 1.31 DeltaE units. All DeltaE values were below a quantitative level that would be considered clinically acceptable. Autoglazed samples were the most color stable, followed by ion exchanged, overglazed, and polished test samples.
  
  
  CONCLUSIONS
  All groups demonstrated color stability below a quantitative level that would be considered clinically acceptable, but long-term clinical studies are necessary to verify these findings.
authors.affiliation: Department of Prosthetic Dentistry, Gülhane Military Medical Academy, Istanbul, Turkey. arzuatay@gmail.com
authors.forename: Arzu
authors.initials: A
authors.lastname: Atay
authors.forename: Selçuk
authors.initials: S
authors.lastname: Oruç
authors.forename: Jülide
authors.initials: J
authors.lastname: Ozen
authors.forename: Cumhur
authors.initials: C
authors.lastname: Sipahi
mesh_terms: D000538:Aluminum Silicates; D003116:Color; D003124:Colorimetry; D003775:Dental Polishing; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D007474:Ion Exchange; D008422:Materials Testing; D017680:Potassium Compounds; D017797:Prosthesis Coloring; D011897:Random Allocation; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D017680:Potassium Compounds; D003776:Dental Porcelain; C016447:feldspar