Evaluation of Different Glazing Techniques of Advanced Lithium Disilicate Ceramics on Color Stability: An invitro study

Aim: Evaluation of the effect of different glazing techniques on color stability of lithium disilicate with virigilite (Cerec Tessera).Materials and Methods: Thirty- Two disks were constructed from advanced lithium disilicate with virigilite at a size of 10 x 14 mm and a thickness of 0.6 and then subjected to four groups based on different surface glazing (n=8) (mechanical polishing, powder glaze, clear glaze paste and glaze paste). After that, samples were subjected to 5000 thermal cycling, followed by immersion in coffee for 12 days. Color change (ΔE) was measured by spectrophotometer using CIELAB color coordinates at the initial state before glazing, as well as after the application of TC and immersion.Results: ΔE was affected significantly by the type of the glaze (p<.001). the Average Delta E in the Clear Glaze Paste, Glaze Paste, and powder glaze Groups was statistically significantly lower than the Mechanical Polishing Group (p=.046 and p=.001, p=1.000 respectively). All ΔE values were above than the selected acceptability threshold (ΔE=3.7) except glaze paste group below it. Glazed samples were more resistant to discoloration than the polished one. ΔE become higher after thermocycling and immersion in coffee solutionConclusion: This study concluded that color stability of cerec tessera showed statistically significant difference among different glazing techniques (p<.001). The lowest color change for all stages was observed in glaze paste group and the highest color change was observed in mechanical polished group.