The Need

Color matching is critical for dental implants, cosmetic and beauty products, paints, textiles, and graphic design. Many techniques to evaluate color are subjective and do not produce consistent results. For example, when teeth are repaired or replaced during a dental procedure, additional material is added and shaded to match the existing teeth. In current practice, shade-matching methods for dental prosthetics are heavily subjective and can vary based on the technician performing the procedure. Colorimeters and spectrophotometers offer solutions that accurately evaluate light absorbance and reflection to determine color, but these devices are expensive. There is a need for a cost-effective, objective technique to evaluate color and match shade.

The Technology

Researchers at The Ohio State University, led by Dr. William Johnston and Dr. Melody Carney, have developed a system that utilizes a digital camera and a set of optical properties to match color. Originally developed to assess translucent dental material, the system selects a shade that produces the smallest CIEDE2000 color difference, or best color match, when given a target shade and backing. This system incorporates several factors, including optical characterization and regression modeling data. The component blending and layering effects within a color match and the consequences of these combined features on the accuracy of a color match were determined and quantified through analysis of a blending model.

Commercial Applications

• Dentistry: restorative and cosmetic dentistry and dental prosthetics
• Cosmetics and beauty products
• Paint
• Textiles
• Graphic design

Benefits/ Advantages

• Lower cost than colorimeters and spectrophotometers
• Eliminates the subjective nature of current methods for shade-matching
• Understanding and exploiting the optical properties that determine which shade is selected could lead to the development of dental composites that produce better aesthetic results