Color comparison between non-vital and vital teeth

PURPOSE: The aim of this study was to define a color space of non-vital teeth and to compare it with the color space of matched vital teeth, recorded in the same patients. MATERIALS AND METHODS: In a group of 218 patients, with the age range from 17 to 70, the middle third of the buccal surface of 359 devitalized teeth was measured using a clinical spectrophotometer (Vita Easyshade Advance). Lightness (L(*)), chromatic parameters (a(*), b(*)), chroma (C(*)), hue angle (h) and the closest Vita shade in Classical and 3D Master codifications were recorded. For each patient, the same data were recorded in a vital reference tooth. The measurements were performed by the same operator with the same spectrophotometer, using a standardized protocol for color evaluation. RESULTS: The color coordinates of non-vital teeth varied as follows: lightness L(*): 52.83–92.93, C(*): 8.23–58.90, h: 51.20–101.53, a(*): −2.53–24.80, b(*): 8.10–53.43. For the reference vital teeth, the ranges of color parameters were: L(*): 60.90–97.16, C(*): 8.43–39.23, h: 75.30–101.13, a(*): −2.36–9.60, b(*): 8.36–39.23. The color differences between vital and non-vital teeth depended on tooth group, but not on patient age. CONCLUSION: Non-vital teeth had a wider color space than vital ones. Non-vital teeth were darker (decreased lightness), more saturated (increased chroma), and with an increased range of the hue interval. An increased tendency towards positive values on the a(*) and b(*) axes suggested redder and yellower non-vital teeth compared to vital ones.