Instrumental Shade Matching

Instruments used for objective color measurements in Dentistry were introduced to fit the needs of dental clinicians, mainly providing information on the corresponding shade tab or color determination. Instrumental shade determination can help to overcome some shortcomings of the classic visual shade-matching method by bringing accuracy, reliability, and stable color readings. Dental color-measuring devices have the ability to provide reliable data and consistent repeated measurements. Although they have shown excellent repeatability and reproducibility in clinical settings, important deviations in color readings were reported from dental spectrophotometric systems. Furthermore, dental spectrophotometers present a high intra-device repeatability of color coordinates, but because of low inter-device repeatability, data obtained from different dental color-measuring devices may not comparable. Yet, research studies have shown that instrumental shade determination is, at least comparable to, if not better than conventional visual shade assessment performed by dental professionals. The colorimetric coordinates can be used to assess the color similarity (color compatibility) between a natural dental tissue and a dental restorative material, between different dental materials, or between a target tooth and the corresponding restoration or shade tab. This chapter also appraises the color stability of different dental materials during manufacturing or controlling color shifts at clinical placement and in follow-up visits of the patient. Additionally, whiteness objective measurements are presented and associated with research and manufacture of dental materials as well as with clinical practice, with applications such as monitoring of tooth whitening and evaluating the effectiveness of different whitening agents.