Common Causes of Errors During the Instrumental Shade Selection Process

Errors associated with surface luster: Smooth tooth surfaces appear brighter compared to uneven/rough surfaces, this may lead to an erroneous reading when a digital system is used. It is suggested that filters be added to the newer shade-matching systems to compensate for this probable error.⁴⁸

Errors associated with translucent teeth/restorations: The surfaces of a translucent tooth/restoration are associated with light loss.^39,48 Modifications should be made to the software to accommodate the loss of light and/or other light-scattering properties of teeth, crowns, and shade tabs. Most of the current digital systems (except digital imaging) cannot correctly replicate the translucency of natural teeth.

Errors associated with probe position: Positioning of the probe is an important factor affecting the accuracy and repeatability of the measurement.^39,48 A device with a small diameter contact probe is unable to record a detailed color map of the tooth surface while a larger diameter probe is often limited to the anterior regions of the mouth.

Errors associated with poor laboratory system alignment: If the laboratory has a different digital system than the practitioner, there will be errors in shade matching.^39,48