Masking Colored Substrates Using Monolithic and Bilayer CAD-CAM Ceramic Structures

2017 ◽  
Vol 42 (4) ◽  
pp. 387-395 ◽  
Author(s):  
GR Basso ◽  
AB Kodama ◽  
AH Pimentel ◽  
MR Kaizer ◽  
A Della Bona ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Pearson Correlation ◽  
Lithium Disilicate ◽  
Color Difference ◽  
Color Variation ◽  
Color Coordinates ◽  
Cad Cam ◽  
Ceramic Thickness ◽  
Monolithic Structures ◽  
Monolithic Structure

SUMMARY Objective: To evaluate the masking ability and translucency of monolithic and bilayer CAD-CAM ceramic structures. Methods: Discs of high translucency (HT) and low translucency (LT) lithium disilicate–based ceramic (IPS e.max CAD) with different thicknesses (0.7, 1, 1.5, and 2 mm) were evaluated as a monolithic structure or combined (bilayer) with a 0.5-mm-thick zirconia framework (IPS e.max ZirCAD). The masking ability and translucency were calculated based on CIE L*a*b* color coordinates measured with a spectrophotometer (SP60, X-Rite). The translucency parameter (TP) was calculated using color coordinates measured over standard white-and-black backgrounds. The masking ability was calculated by CIEDE2000 color difference metric (ΔE00) for each specimen measured over a tooth-colored substrate (shade A2) compared to three darker backgrounds (shade C4 and two metal substrates). Confidence intervals (CI) for the means (95% CI) were calculated for TP and ΔE00. The Pearson correlation between ΔE00 and TP was investigated for monolithic and bilayer structures over all backgrounds. Results: The thinner the lithium disilicate layer, the greater the translucency and the higher the ΔE00 values. The effect of ceramic thickness on both translucency and masking ability was more pronounced for the monolithic structures. In addition, monolayers always presented a greater color variation than their bilayer counterparts. The metallic background produced greater ΔE00 than the C4-shaded substrate. Conclusion: Monolithic veneers were able to mask C4-shaded background but did not mask metallic backgrounds. Bilayer structures showed greater shade masking ability than monolithic structures.

scholarly journals LED and Halogen Light Transmission through a CAD/CAM Lithium Disilicate Glass-Ceramic

2015 ◽  
Vol 26 (6) ◽  
pp. 648-653 ◽  
Author(s):  
Carolina Nemesio de Barros Pereira ◽  
Cláudia Silami de Magalhães ◽  
Bruno Daleprane ◽  
Rogéli Tibúrcio Ribeiro da Cunha Peixoto ◽  
Raquel da Conceição Ferreira ◽  
...  
Keyword(s):  
Regression Model ◽  
Glass Ceramic ◽  
Light Transmission ◽  
Light Attenuation ◽  
Lithium Disilicate ◽  
Strong Negative Correlation ◽  
Halogen Light ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Thickness

The effect of thickness, shade and translucency of CAD/CAM lithium disilicate glass-ceramic on light transmission of light-emitting diode (LED) and quartz-tungsten-halogen units (QTH) were evaluated. Ceramic IPS e.max CAD shades A1, A2, A3, A3.5, high (HT) and low (LT) translucency were cut (1, 2, 3, 4 and 5 mm). Light sources emission spectra were determined. Light intensity incident and transmitted through each ceramic sample was measured to determine light transmission percentage (TP). Statistical analysis used a linear regression model. There was significant interaction between light source and ceramic translucency (p=0.008) and strong negative correlation (R=-0.845, p<0.001) between ceramic thickness and TP. Increasing one unit in thickness led to 3.17 reduction in TP. There was no significant difference in TP (p=0.124) between shades A1 (ß1=0) and A2 (ß1=-0.45) but significant reduction occurred for A3 (ß1=-0.83) and A3.5 (ß1=-2.18). The interaction QTH/HT provided higher TP (ß1=0) than LED/HT (ß1=-2.92), QTH/LT (ß1=-3.75) and LED/LT (ß1=-5.58). Light transmission was more effective using halogen source and high-translucency ceramics, decreased as the ceramic thickness increased and was higher for the lighter shades, A1 and A2. From the regression model (R2=0.85), an equation was obtained to estimate TP value using each variable ß1 found. A maximum TP of 25% for QTH and 20% for LED was found, suggesting that ceramic light attenuation could compromise light cured and dual cure resin cements polymerization.

scholarly journals Effects of substrate, ceramic thickness, translucency, and cement shade on the color of CAD/CAM lithium‐disilicate crowns

2019 ◽  
Vol 31 (5) ◽  
pp. 457-464 ◽  
Author(s):  
Alexandra Czigola ◽  
Emese Abram ◽  
Zoltan I. Kovacs ◽  
Krisztina Marton ◽  
Peter Hermann ◽  
...  
Keyword(s):  
Lithium Disilicate ◽  
Cad Cam ◽  
Ceramic Thickness

Effect of Lithium Disilicate Ceramic Thickness on the Color of Discromic Substate

2014 ◽  
Vol 614 ◽  
pp. 95-99
Author(s):  
Alexandra Botos ◽  
Cristina Gasparik ◽  
Horatiu Colosi ◽  
Mandra Badea ◽  
Diana Dudea
Keyword(s):  
Composite Material ◽  
Statistical Analysis ◽  
Sucrose Solution ◽  
Lithium Disilicate ◽  
Color Difference ◽  
Ceramic Layer ◽  
Color Parameters ◽  
Die Material ◽  
Ceramic Thickness ◽  
Ceramic Restorations

The aim of this study was to evaluate the influence of the thickness of lithium disilicate ceramics (medium opacity) on the color perception of pressed full-ceramic restorations, in various situations of discromic substrate. The color parameters of ceramic disks (10 mm diameter, thickness 0.3, 0.6, 0.9, 1.2, 1.5mm), (n=5), of IPS e.max® Press MO 0 (Ivoclar Vivadent) were evaluated upon samples of light cured composite material that simulate the shade of prepared teeth (IPS Natural Die Material Kit, Ivoclar Vivadent) (disks 10mm diameter, 5mm thickness). Saturated sucrose solution was interposed between the ceramic disks and the composite disks. The color parameters CIE L*, a*, b* were recorded by using a spectrophotometer (VITA Easyshade® Advance, VITA Bad Säckingen, Germany). The color difference E was calculated. Statistical analysis of the data revealed that the increase in thickness of the ceramic layer will lead to an increased masking of the discolored background by the ceramic layer.

Color Masking Ability of Lithium Disilicate Ceramic for Titanium Alloy Implant Abutments

2020 ◽  
Vol 10 (6) ◽  
pp. 852-857
Author(s):  
Fahim Vohra ◽  
Sulaiman Alnajashi ◽  
Abdulwahab Aljardi ◽  
Modhi Al Deeb ◽  
Laila Al Deeb ◽  
...  
Keyword(s):  
Color Stability ◽  
Lithium Disilicate ◽  
Color Difference ◽  
Study Groups ◽  
Implant Abutments ◽  
Implant Abutment ◽  
Color System ◽  
Cad Cam ◽  
The Difference ◽  
Post Hoc

The aim was to assess the acceptable thickness of monolithic Lithium Disilicate (LD) ceramic in masking of Titanium (Ti) implant abutment by comparison to Zirconium (Zr) crowns through color matching. Forty LD and 10 Zr copings (control) using Hot-pressing and CAD-CAM techniques were fabricated. A standard Ti abutment (Straumann, ITI, Basel, Switzerland) was used as foundation substrate. LD crowns were divided into different thickness [1.0 mm (n = 10), 1.2 mm (n = 10), 1.5 mm (n = 10) and 1.8 mm (n = 10)] and 10 Zr copings (control) had 0.5 mm thickness. Different crown materials and crown thicknesses resulted in 5 study groups designated as Zr-Ti-0.5, LD-Ti1.0, LD-Ti-1.2, LD-Ti-1.5 and LD-Ti-1.8. Specimens were cemented to Ti abutments and using a spectrophotometer the difference of color for specimen and controls was determined by comparing ΔL, Δa and Δb (CIELab color system) and an overall ΔE. These were statistically compared using analysis of variance and Tukey post hoc multiple comparisons. Among LD specimens with Ti abutments, lowest color difference was achieved for LD-Ti-1.8 (2.3 ± 0.31) and the highest color difference was for LD-Ti-1.0 (4.93 ± 0.45). The lowest ΔE was recorded for Zr copings (control), which was lower than (p < 0 01) LD crowns of 1.0 and 1.2 mm thickness. LD crown thickness had a significant effect on ΔE (color difference) on Ti abutments. Masking of Ti abutments by 1.5 mm LD crowns was comparable to Zr specimens (control). Lithium disilicate crown of 1.5 mm thickness showed statistically comparable color stability to 0.5 mm Zr copings on Ti implant abutments.

Evaluation of bond strength of dual resin cements to CAD/CAM-created lithium disilicate ceramic

2020 ◽  
Vol 69 (3) ◽  
Author(s):  
Felipe Sczepanski ◽  
Cláudia R. Brunnquell ◽  
Sandrine B. Berger ◽  
Eloisa A. Paloco ◽  
Murilo B. Lopes ◽  
...  
Keyword(s):  
Bond Strength ◽  
Lithium Disilicate ◽  
Resin Cements ◽  
Cad Cam

scholarly journals Effectiveness of Combination of Dentin and Enamel Layers on the Masking Ability of Porcelain

2015 ◽  
Vol 26 (6) ◽  
pp. 654-659 ◽  
Author(s):  
Noéli Boscato ◽  
Fernando Gabriel Hauschild ◽  
Marina da Rosa Kaizer ◽  
Rafael Ratto de Moraes
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Color Variation ◽  
Color Coordinates ◽  
Dentin Thickness ◽  
Cielab Color

This study evaluated the masking ability of different porcelain thicknesses and combination of enamel and/or dentin porcelain layers over simulated background dental substrates with higher (A2) and lower (C4) color values. Combination of the enamel (E) and dentin (D) monolayer porcelain disks with different thicknesses (0.5 mm, 0.8 mm, and 1 mm) resulted in the following bilayer groups (n=10): D1E1, D1E0.8; D1E0.5; D0.8E0.8; D0.8E0.5, and D0.5E0.5. CIELAB color coordinates were measured with a spectrophotometer. The translucency parameter of mono and bilayer specimens and the masking ability estimated by color variation (ΔE*ab) of bilayer specimens over simulated dental substrates were evaluated. Linear regression analysis was used to investigate the relationships translucency parameter × ΔE*, translucency parameter × porcelain thickness, and ΔE* × porcelain thickness. Data were analyzed statistically (α= 0.05). Thinner porcelain disks were associated with higher translucency. Porcelain monolayers were considerably more translucent than bilayers (enamel + dentin). Dentin porcelain was less translucent than enamel porcelain with same thickness. ΔE* was always lower when measured over A2 background. Higher ΔE* was observed for the C4 background, indicating poorer masking ability. Increased ΔE* was significantly associated with increased translucency for both backgrounds. Decreased translucency and ΔE* were associated with increased total porcelain thickness or increased dentin thickness for both backgrounds. In conclusion, increased porcelain thickness (particularly increased dentin layer) and increased porcelain opacity resulted in better masking ability of the dental backgrounds.

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