J Adv Prosthodont.  2022 Feb;14(1):56-62. 10.4047/jap.2022.14.1.56.

Color stability of fully- and pre-crystalized chair-side CAD-CAM lithium disilicate restorations after required and additional sintering processes

• KMID: 2526760
• DOI: http://doi.org/10.4047/jap.2022.14.1.56

Abstract

PURPOSE
The aim of this study was to investigate shade changes in fully- and pre-crystalized CAD-CAM lithium disilicate crowns after the required and additional firing processes.
MATERIALS AND METHODS
One hundred and five crowns of shade A1 with high translucency were milled out of CAD-CAM lithium disilicate blocks and categorized as follows (n = 15): (1) restorations fabricated from Straumann n!ce with no additional sintering process; (2) restorations fabricated from Straumann n!ce with one additional sintering process; (3) restorations fabricated from Straumann n!ce with two additional sintering processes; (4) restorations fabricated from Amber Mill with one sintering process; (5) restorations fabricated from Amber Mill with two sintering processes; (6) restorations fabricated from IPS e.max CAD with one sintering process; (7) restorations fabricated from IPS e.max CAD with two sintering processes. All restorations were evaluated with a color imaging spectrophotometer.
RESULTS
All restorations presented some color alteration from the original shade both after a single and after two firing processes.
CONCLUSION
The required and additional sintering processes for restorations fabricated with chairside CAD-CAM lithium disilicate blocks cause an alteration of the original shade selected. Shade A1 high translucency restorations tend to change to a more yellowish B1 shade after a sintering process.