Premium
An In Vitro Investigation of Veneered Zirconia‐Based Restorations Shade Reproducibility
Author(s) -
AlWahadni Ahed,
Shahin Ahmad,
Kurtz Kenneth S.
Publication year - 2018
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.12489
Subject(s) - chamfer (geometry) , cubic zirconia , materials science , finish line , reproducibility , dental porcelain , composite material , dentistry , orthodontics , mathematics , ceramic , medicine , geometry , geology , paleontology , statistics , race (biology)
Purpose To examine the effects of the veneering technique on the shade reproducibility of zirconia‐based crowns. Materials and Methods An artificial tooth was prepared with a 1.2 mm heavy chamfer finish line and 8° taper. The prepared tooth was scanned using CAD/CAM technology to fabricate 45 cobalt chromium (CoCr) testing dies. One CoCr die was scanned, and 45 zirconia copings were milled and devided according to the veneering technique into 3 groups of 15 specimens each: layering veneering (LV) using Vita Vm9, overpressing veneering (OV) using Vita Pm9, and digital veneering (DV) using Vita Triluxe forte. All veneering layers had the same shade (A2). The specimens were cemented onto the testing dies using glass inomer cement. A spectrophotometer was used to measure the shade coordinates (L, C, h, a, b) for a Vita A2 shade tab and for each specimen. Both the CIE Lab (ΔE ab ) and the CIE DE2000 (ΔE 00 ) color difference formulas were applied to compare the shade tab and the study groups. One‐way ANOVA and multiple comparison Bonferroni tests were applied for statistical analysis of the results. Results Means and standard deviations (SDs) of ΔE ab were 2.3 ± 1.3 for LV, 3.5 ± 0.8 for OV, and 4.0 ± 0.7 for DV. Means and SDs of ΔE 00 were 1.4 ± 0.8 for LV, 2.1 ± 0.5 for OV, and 3.1 ± 0.4 for DV. ΔE ab of LV group was significantly lower ( p < 0.05) than both OV and DV groups, whereas the difference in ΔE ab between OV and DV groups was not significant ( p = 0.39). The differences in ΔE 00 between all groups were significant ( p < 0.05). Conclusions LV group was superior to other groups in terms of shade reproducibility. The ΔE ab and the ΔE 00 values of LV and OV groups were within clinically acceptable ranges; however, the ΔE ab and the ΔE 00 values of group DV were beyond the clinically acceptable ranges. The ΔE 00 formula demonstrated a statistically significant difference between OV and the DV groups, while the ΔE ab formula did not. The zirconia veneering technique had a significant influence on the shade reproducibility of zirconia‐based crowns.