Strategies for Masking Metal Show-Through in Disilicate Dental Ceramics: A Systematic Evaluation Using Different...

Area of Science:

• Dental Materials Science
• Prosthodontics
• Esthetic Dentistry

Background:

• Metallic core buildups can pose esthetic challenges for ceramic restorations.
• Lithium disilicate ceramics are widely used for their strength and esthetics.
• Assessing masking ability is crucial for predictable shade matching.

Purpose of the Study:

• To evaluate the masking effect of two lithium disilicate ceramics (IPS e.max CAD and GC Initial LiSi) on metallic core buildups.
• To determine the influence of ceramic thickness and opaquer application on masking.
• To compare the performance of the two ceramics using spectrophotometry and digital photocolorimetry.

Main Methods:

• Two lithium disilicate ceramics were tested at thicknesses of 1.0, 1.5, and 2.0 mm.
• Ceramics were bonded to opaqued and non-opaqued amalgam substrates.
• Masking was assessed using spectrophotometry and polarized digital photocolorimetric (PDPC) analysis, measuring color differences (ΔE₀₀).

Main Results:

• IPS e.max CAD demonstrated superior masking compared to Initial LiSi, especially when used with an opaquer.
• With opaqued amalgam, IPS e.max achieved acceptable (1.5 mm) and excellent (2.0 mm) masking.
• Initial LiSi showed acceptable masking only at 2.0 mm thickness on opaqued amalgam.

Conclusions:

• Resin-based opaquers are effective for masking metallic substrates under lithium disilicate restorations.
• IPS e.max CAD provides better masking performance than Initial LiSi, particularly with opaquers.
• This approach supports conservative dentistry by potentially avoiding replacement of metallic restorations.