One of the side effects of portable cameras and selfie culture is that people are taking pictures of themselves in many different situations. You might be taking pictures of yourself having fun outside, enjoying lunch with a friend under restaurant lights, dancing at the club, or even hanging out at work.

And you might notice that your teeth look very different in all the pictures. Sometimes, your teeth might look bright white. Other times, they might look more yellow, brown, or even gray. You know you aren’t changing your teeth depending on the situation, so why do they look different colors? And how do you decide when it’s time for teeth whitening?

The reason for this comes from the nature of light and how our eyes perceive whiteness in teeth. This can make your teeth look different colors in different lights–even though the lights might seem the same color. In some cases, it can even make your restorations stand out more than you’d like.

pretty young woman looking at her phone while walking with an umbrella

What Makes Teeth Look White

Our eyes perceive color on the basis of the light that’s being reflected, scattered, or transmitted through an object. Something looks blue, for example, if it tends to reflect or scatter light of wavelengths we define as being in the blue part of the spectrum.

If you remember your rainbow acronym–ROYGBIV–you might notice something: there’s no “W” for white. (Nor is there a second “B” for black.) Instead, we perceive objects as white if they reflect light fairly evenly across the spectrum.

Different Lights Make Your Teeth Look Different

The problem is that not all light sources give off the same balance of light across the spectrum as natural sunlight. This is becoming even more pronounced now that there are so many more options for residential and professional lighting, including incandescent, fluorescent, compact fluorescent, halogen, and LED lights all give off different spectra of light. And while all these lights might look pretty much white to us, they’re not the same.

The differences between lights become more pronounced when we are considering not the light given off by the source, but the light reflected from our teeth. The difference in yellow reflection versus blue reflection might not matter as much when a light source is strong in both colors of light, but if a light source is already weak in blue light, it can make your teeth look more yellow than they look in other lights.

When to Whiten Teeth

Since your teeth can look whiter in some lights than others, how do you know when to whiten your teeth? The answer is the same as it’s always been: when a discolored appearance bothers you. If you’re only rarely in light where your teeth look yellow or those are situations where your smile doesn’t matter as much, you might not want to whiten your teeth. But if you are often in places where your teeth look yellow, maybe you do (assuming, of course, that you can’t just change to a more flattering light).

Restorations Can Stand Out Under Different Lights

This problem of light absorption and reflection becomes even more serious when we look at cosmetic dentistry and other dental restorations. Dental restorations aren’t made of natural tooth enamel, which means that they have different patterns of light absorption than natural tooth enamel. This means that while they might look the same color as your natural teeth in some lights, they might not look the same color in all lights. This phenomenon is called metamerism, and it can make you unhappy with the results of cosmetic dentistry procedures like bonding, veneers, or dental crowns.

If you run into this problem, there are several solutions. First, if you can change the lights, you might consider it. Second, you can get different restorations that match better under the lights where you spend most of your time. Finally, you can get matching restorations on all your visible teeth so that they always match under all different lights.

Beautiful Smiles in All Situations

We understand that you don’t want a smile that’s beautiful only part of the time. At StarImage Dentistry, we take all factors into account to give you a smile that looks beautiful in all situations.

Whether you’re concerned about the appearance of your natural smile or your restorations, we can help. Please call 940-322-2252 today for an appointment with a Wichita Falls cosmetic dentist.