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Effect of grinding on the optical properties of monolithic zirconia
Author(s) -
Corcodel Nicoleta,
Herpel Christopher,
Rammelsberg Peter,
Rion Kevin,
Seceleanu Irina
Publication year - 2022
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12898
Subject(s) - cubic zirconia , grinding , materials science , composite material , color difference , artificial intelligence , ceramic , computer science , enhanced data rates for gsm evolution
Abstract Objectives The purpose of this study was to analyze the color infiltration in monolithic zirconia after grinding, which plays an essential role in the color stability of restorations after occlusal adjustment. Methods One hundred and eight white zirconia plates (36 Dentsply Sirona—Cercon high translucency [C], 36 Zirkonzahn—Prettau [P], 36 Zirkonzahn—Prettau anterior [Pa]) were stained by infiltration with target colors Vita A2, A3.5, and A4. In a standardized experimental setup, all plates were grinded in nine successive steps (from baseline to 500 μm), and color was measured with a spectroradiometer at each grinding step. Color differences ΔE 00 between initial color and after each grinding step were calculated. The data was analyzed using regression, Kruskal‐Wallis test, inverse prediction, and simultaneous 95%‐confidence intervals. Results Grinding had a significant effect on color stability across all zirconia types and target colors ( p < 0.001). At each cut level and target color, ΔE 00 means for groups C, P, and Pa were statistically different ( p < 0.05). Among the three zirconia types, Pa had the lowest ΔE 00 mean score for cut levels 20–100 μm for A2 and between 50 and 300 μm for A3.5 and A4. For all other cut levels, differences between Pa and P were not significant (α = 0.05). C had the largest mean ΔE 00 except for A4 until 100 μm, where it was second best. Conclusion Zirconia type had a significant effect on the color infiltration depth across all target colors. Pa showed the best color stability until 150 μm material reduction, whereas C presented significantly less color stability than the other two zirconia materials. Clinical significance Color stability is important for minimizing the risk of restoration failure due to unacceptable color changes after grinding. Pa is less susceptible to color change and has an additional buffer of 60 μm until exceeding the color acceptability threshold. When higher flexural strength is needed, P is to be preferred.