Translucency of Dental Ceramic, Post and Bracket.

Translucency of dental ceramics, esthetic posts and orthodontic brackets was reviewed. Translucency parameter () and contrast ratio () are generally used for translucency evaluation. For the evaluation of translucency, two criteria such as the translucency of human teeth ( = 15-19, 1 mm thick) and the visual perceptibility threshold for the translucency difference (∆ > 0.07 or ∆ > 2) were used. In ceramics, translucency differences were in the perceptible range depending on the type of material and the thickness. However, variations caused by the difference in the required thickness for each layer by the material and also by the measurement protocols should be considered. As to the translucency of esthetic posts, a significant difference was found among the post systems. Translucency was influenced by the bracket composition and brand, and the differences by the brand were visually perceptible.