Two people can have teeth that match the same shade tab, and one smile will look healthy while the other looks fake. The difference is rarely the brightness alone. Teeth look too white when every tooth is one flat, opaque colour from the gum to the edge, with none of the gentle variation real enamel has. A natural result keeps that variation and stays in proportion to the rest of your face.
Written by Dr James Tran, BDent (University of Sydney), MICOI, GradDip (Oral Implants), general dentist at Lumi Dental in Melrose Park.
Real teeth are several colours at once
Enamel is partly see-through. Most of the colour you notice comes from the dentine underneath, seen through a layer of enamel that varies in thickness across the tooth. Near the gum the enamel is thin, so the warmer dentine shows and the tooth looks slightly deeper in colour. Across the middle the tooth is at its lightest. At the biting edge there is enamel but little or no dentine behind it, so the edge can look faintly grey or bluish and lets light through.
Canines usually sit a little warmer than the four front teeth, and lower front teeth often look darker than the uppers, which our article on why lower teeth look darker explains. When whitening goes well, all of these relationships survive: every tooth is lighter, yet the gum line is still a touch warmer, the edges still glow, and the canines still sit a step behind. When a smile looks painted on, those details have usually disappeared.
How shade is recorded
The VITA classical shade guide has 16 tabs grouped into four letter families, A to D, with numbers that rise as the tabs get darker. When the tabs are lined up by lightness, B1 comes first, so it is often used as shorthand for the lightest natural tooth colour. Our tooth shade matching guide explains the system in more detail.
Small changes are easy to see. In a 2017 study in the Journal of Dentistry, Westland and colleagues showed 32 observers digital images of teeth and found that a lightness change of about 1.1 units on the CIELAB colour scale was enough to be noticed. The study was carried out on a calibrated screen rather than in the mouth, but it is a reminder that even modest whitening produces a visible change, and that more is not always needed.
Skin tone is a weak guide to the right shade
A common piece of advice is to choose a whitening shade to suit your complexion. The research does not back that up well. A 2020 study of 338 people at Kathmandu Medical College, published by Pradhan and colleagues, compared upper front tooth shade with skin colour. Lighter shades were common in people with fair, medium and dark skin, the most frequent shade was B1 in the fair and medium groups and B2 in the dark group, and the authors found no relationship between skin tone and tooth colour.
Skin colour does change contrast, though. The same teeth can look brighter against tanned or darker skin, which is a reason to be a little more conservative with the target rather than a reason to accept a yellower shade. Our article on skin tone, tan and how white your teeth look covers this effect.
Use the whites of your eyes as a reference
A more practical comparison is the white of your eye. It is a natural white that already belongs to your face. Teeth that sit at about the same brightness, or slightly below, tend to look clean and healthy; teeth that are clearly brighter than the eyes can start to look artificial. Our guide to the whites of your eyes and tooth shade goes through the comparison.
Check this in daylight from a window rather than under bathroom downlights or a ring light, which can exaggerate brightness. Many people find it helps to set a target one step short of the lightest shade they think they would like. Teeth tend to look brighter for a few days after whitening, because the enamel has dried out a little, and then settle; our article on whitening rebound explains why. It is easy to top up later, and not possible to undo.
Crowns, veneers and fillings will not change
Whitening products only lighten natural enamel. The Australian Dental Association's teeth.org.au site notes that treatment will not change the colour of porcelain crowns, veneers or white composite fillings, and that if these no longer match after whitening, your dentist might need to replace them.
In practice, any visible restoration sets a limit. If you have a front crown in a mid shade, you can either whiten to roughly that shade and stop, or plan to replace the crown once your new natural colour has settled. Our guide to whitening veneers and crowns lays out the choices.
Natural looks different at 25 and at 60
Teeth tend to darken with age as enamel wears thinner and the dentine underneath becomes deeper in colour. A 2022 retrospective study by Bhaskaran and Sharma of 238 adults in India found that people over 45 had significantly darker shades than younger groups. Across the whole sample, A2 was the most common shade, recorded in about 35% of people.
Older adults can still whiten successfully. It simply means that natural is relative to age. A very light shade on an older face can look more striking than the same shade on someone in their twenties, so a modest change from your starting point often looks more like you than aiming for the top of the shade guide.
If the result looks too bright at first
Give it time. A chalky or very bright look in the first days after whitening is usually from temporary drying of the enamel, and the colour settles over the following week or two. Over the months after that, everyday food and drink usually bring the shade back slightly towards a warmer tone.
Planning a shade with us
Whitening at Lumi Dental starts with an examination by a dentist, and clinical photographs taken under consistent lighting record your starting shade so we can talk about a realistic target together. We do not promise a particular shade, because each person's teeth respond differently. Our options are Lumi Home, a take-home course, and Lumi Refresh and Lumi Radiance, which combine an in-chair session with take-home whitening; all three include Boutique take-home whitening. The teeth whitening page explains how they work. If you are considering porcelain instead, the shade for porcelain veneers is chosen in the same way, against your remaining natural teeth and your eyes.
Common questions
Is B1 too white?
For most adults it is within the natural range, since it is the lightest tab on the classical guide. It can look too white if the teeth have lost their translucent edges, sit clearly brighter than the whites of the eyes, or leave older crowns and fillings looking darker beside them.
Why do some smiles look fake?
Usually because every tooth is the same bright, opaque colour with no difference between the gum line, the middle and the edge. This is more often seen with veneers or crowns made in very light shades than with whitening of natural teeth, which keeps the enamel's natural variation.
How do I choose a shade if I wear makeup or have a tan?
Look at your teeth in daylight against the whites of your eyes rather than your skin, and be slightly conservative if you are often tanned, because darker skin makes the same teeth look brighter.
Unsure how far to go?
If you want a brighter smile that still looks like your own, we can record your current shade and talk through a sensible target before any treatment starts. Book a free cosmetic consult at our Melrose Park practice, or read more about teeth whitening at Lumi Dental.
Sources
- Westland S and colleagues. Investigation of the perceptual thresholds of tooth whiteness. Journal of Dentistry, 2017
- Pradhan D, Shrestha L, Lohani J. Tooth shade and skin colour: a descriptive cross-sectional study. JNMA Journal of the Nepal Medical Association, 2020
- Bhaskaran R, Sharma S. Does age determine the lightness and darkness of tooth shades? A retrospective study. Journal of Advanced Pharmaceutical Technology and Research, 2022
- Australian Dental Association (teeth.org.au): Teeth whitening
About the author
Dr James Tran is a general dentist at Lumi Dental in Melrose Park. He holds a BDent from the University of Sydney and a Graduate Diploma in Oral Implants, and is a Master of the International Congress of Oral Implantologists (MICOI).
This article is general information only and is not a substitute for an examination and individual advice from a registered dental practitioner. Suitability for any treatment varies from person to person.
