Color Perception in Dental Technology: Why Color Is Created in the Mind

• Color is not a property of light or objects but a perception of the brain.
• To determine color in dentistry precisely, three components are needed: The light, an object, and the viewer.
• Modern LED technology allows new standards in color reproduction.
• A technical article by MDT Sascha Hein provides information on this.

In an article for the “dental dialogue” specialist magazine, MDT Sascha Hein gets to the bottom of a widespread misconception: Neither light nor objects are actually colored – color only arises in our brain. This finding has far-reaching consequences for everyday work in the laboratory, especially for workplace lighting. What does good lighting for dental technology call for?

➤ You can also read Sascha Hein's analysis of optimal workplace lighting in our article “The science of laboratory lighting: Basic principles for optimal working” 

Sascha Hein quotes physicist Isaac Newton as saying, “Light is not actually colored; it only appears that way to us.” This initially surprising statement makes sense when we understand how color perception functions: Our brain interprets light wavelengths as different colors. However, only a small section of the electromagnetic spectrum is visible to us.

Three elements are usually needed to perceive colors:

• the light source that emits electromagnetic radiation,
• the object that reflects or absorbs certain wavelengths, and
• the viewer, whose brain interprets the incoming signals as color

The practical significance for dental technology: The number of colors recognizable in the spectrum varies from person to person and may be as many as 100. This individual perception represents a major challenge when determining shades of color in dentistry.
 

The history of artificial lighting shows a steady development:

• Light bulbs: uneven spectrum, low efficiency
• Fluorescent tubes: They have an improved spectrum but contain environmentally dangerous mercury
• Modern LEDs: spectral optimization is possible

This technological evolution now enables new solutions, such as Renfert’s LIGHT 1. By combining specially selected types of LED, it achieves

• a color temperature of 6500 K, corresponding to standard daylight,
• a CRI value of Ra 97 (with extended color matching of 14 colors), which enables particularly true-to-life color reproduction, and
• a balanced spectrum for precisely assessing tooth color shades

Sascha Hein’s practical comparative measurements prove that the spectral energy distribution of the LIGHT 1 is particularly close to the standard daylight source. This is vital for correctly perceiving and reproducing tooth color shades in the laboratory.

One important criterion for the quality of a light source is the Color Rendering Index (CRI). It is determined by comparing the color rendering of a light source with a defined reference source. The standard is the average daylight at noon in the northern hemisphere. The comparison is made using eight defined test colors, whereby the color temperature of the reference source is adjusted to the light source to be tested. 

With a color temperature of 6500 K, the LIGHT 1 comes particularly close to standard daylight and at the same time achieves a very high CRI value of Ra 97 (with an extended color matching of 14 colors). The balanced spectral energy distribution permits particularly true-to-life color reproduction.

Understanding color perception helps us better understand lighting requirements in the laboratory. We can only work precisely and efficiently if all the components – light source, working environment and visual perception – are optimally coordinated.

➤ You can download the complete article by Sascha Hein with detailed technical analyses from dental dialogue here (in German language only): Download 

➤ Further valuable information on the subject of workplace lighting and light science can also be found directly on Sascha Hein's personal blog page and his other blog article on LIGHT 1.