Comparison of the light transmission of new generation monolithic zirconia materials and lithium disilicate.

Purpose: To compare the effects of different thicknesses of ceramic veneering on the light transmission of various monolithic zirconia and lithium disilicate materials used in esthetic restorations.

Methods: Zirconia (i.e., Katana UT, Katana HT, Prozir Diamond, Prozir HT, and Zenostar MO) and lithium disilicate specimens (i.e., Emax HT and Emax MO) were prepared at thicknesses of 0.5 mm, 0.8 mm, and 1.2 mm. Additionally, 0.8 mm-thick specimens and 0.3 mm-thick ceramic veneer were prepared for veneering groups. The total transmittance of light values were measured using a spectrophotometer. The light transmission values were analyzed using the Kruskal-Wallis and the post-hoc Dunnett tests (α= 0.05).

Results: The Emax HT group defined significant differences from all groups (P< 0.05) at all thicknesses. The mean total transmittance of light ranged from 5.53% to 19.55%. There was no significant difference between the Katana UT and Prozir Diamond groups at the 0.5 mm, 0.8 mm, and 1.2 mm thicknesses (P> 0.05).

Clinical significance: The results of this study showed no significant effects of veneering ceramic on the light transmittance of the specimens at a thickness of 0.8 mm. Novel monolithic zirconia materials may be preferred over porcelain veneering in 0.8 mm-thick restorations, as the esthetic appearance of the restorations would not change.