[Color determination in dental ceramics]

Area of Science:

• Dental Materials Science
• Colorimetry
• Esthetic Dentistry

Context:

• Accurate shade selection is crucial for esthetic dental restorations.
• Traditional shade guides lack objectivity and can be unreliable.
• Objective color measurement tools are needed in clinical practice.

Purpose:

• To evaluate the validity of the Castor objective colorimeter for dental shade determination.
• To compare the color characteristics of different dental porcelains (PFM, Mark II, Dicor) using spectrometry and the Castor device.
• To assess the influence of sample thickness and glaze firing on color values.

Summary:

• The Castor colorimeter was used to measure the color values (L*, a*, b*) of PFM, Mark II, and Dicor porcelains, and a Vita shade guide.
• PFM porcelain lightness remained stable post-glaze firing, with shifts in red-green and blue-yellow values.
• Mark II and Dicor lightness decreased with sample thickness; background influence was minimal above 1.5 mm.
• Shade guide lightness order did not match manufacturer claims, but color intensity did.
• The Castor equipment provides objective, economically viable color evaluation for dental applications.

Impact:

• The Castor colorimeter represents a significant innovation for objective dental color assessment.
• It enables accurate measurement of lightness (L*), red-green (a*), and yellow-blue (b*) values.
• This tool can improve the predictability and success of esthetic dental restorations.