Tooth, Nonvital

Visual shade matching is the most common method, in which a color standard from a commercially available dental shade guide is compared to and matched with the target tooth. However, several factors can contribute to perception errors including: different lighting variables, multiple shade systems available in the market with lack of standardization in color systems and corresponding porcelain systems, individual human variables in color perception and lack of understanding of color science.
Therefore, in order to eliminate the uncontrolled variables during the color matching process, instrumental methods have been developed. Spectrophotometric measurement methods employing computer calculations, based on color science and theories, allow quantitative evaluation which is objective and appears to be more accurate. However, extremely high costs, relatively low performance with respect to agreements of the computer-aided devices, and edge loss error make it less acceptable.
One of the most powerful tools in communicating with both patients and dental ceramists is digital photography. Hence, this study is designed to explore the possibilities of a novel approach to shade management (eLABor_aid) utilizing a photocolorimetric (PCM) method and subsequent shade formulation without the use of stock shade guides in comparison to well-known visual and instrumental methods.
The aim of the study is to evaluate the accuracy of digital photography combined with shade analyzing software (eLAB) in optimizing shade matching when compared to conventional and instrumental methods of shade selection.
A Null Hypothesis is suggested where no significant difference regarding shade selection between eLAB protocol, conventional and instrumental methods will be found.

This study aims to evaluate the clinical performance of the zirconia laminate veneer, a minimally invasive prosthetic restoration