Spectrophotometric Evaluation of Color Matching between Acrylic Resin-Based Artificial Teeth and Conventional Shade Guides: An in Vitro Comparative Study

Introduction: Accurate shade selection is essential for achieving aesthetic harmony in prosthetic restorations. However, discrepancies often arise when matching commercial prosthetic teeth with standardized shade guides. This study aimed to evaluate the chromatic compatibility between commercially available prosthetic teeth and two types of shade guides: the conventional Vita Classic？ and manufacturer-specific shade guides. Methods: An in vitro comparative study was conducted on 13 brands of prosthetic teeth widely distributed in the Moroccan market. Color assessment was limited to shades A1, A2, and A3, based on their high prevalence in the local population. Color measurements were performed using the Spectroshade？ spectrophotometer and analyzed in the CIE Lab* color space. Delta-E values were calculated to quantify the chromatic deviation between the commercial teeth and the reference shade tabs. The threshold of visual perceptibility was set at ΔE = 3.7. Results: Significant chromatic discrepancies were found between most commercial prosthetic teeth and the Vita Classic？ shade tabs, with average Delta-E values exceeding the perceptual threshold. Only the Ivoclar？ (original) brand showed consistent matching with its own shade guide across all tested shades. The Acry Lux？ brand demonstrated acceptable results for select shades. Additionally, no direct correlation was observed between the number of resin layers and color matching precision. Conclusion: This study highlights the limitations of using universal shade guides such as Vita Classic？ for selecting commercial prosthetic teeth. Manufacturer-specific shade guides, particularly those provided by Ivoclar？ and Acry Lux？, showed greater chromatic accuracy. Clinicians are encouraged to prioritize shade selection based on the actual prosthetic teeth to be used and to employ digital shade matching tools to minimize subjective variability and improve aesthetic outcomes.