Compared with the two front teeth, the canines (the pointed teeth at the corners of the smile) usually measure darker, more yellow and more saturated in colour. Research measuring natural teeth shows this pattern, so on its own it is not a sign of staining or damage. It also means the canines may change less than the incisors during whitening, and in many people they still look a little deeper afterwards.
Colour measurements show the canines are the most saturated front teeth
Dentists describe tooth colour with three values: lightness (how light or dark), chroma (how strong or saturated the colour is) and hue (which colour family, such as yellow or red). A spectrophotometer measures these values with a handheld device, which gives a more objective reading than matching by eye.
Pustina-Krasniqi and colleagues (European Journal of Dentistry, 2017) measured the upper front teeth of 255 people this way. On average, the canines had the lowest lightness and the highest chroma of the three tooth types, were more yellow, and leaned slightly more towards red than the incisors, which leaned slightly towards green. The differences between central incisors, lateral incisors and canines were statistically significant and, the authors judged, large enough to matter clinically.
A study of 62 people by Falcone and colleagues (International Journal of Prosthodontics, 2016) found that in most people the central incisor and the canine did not even fall in the same shade family on the VITA Classical shade guide. The colour difference between them tended to be smaller in older people, and most of that change came from the central incisor. The canine's colour stayed much the same across ages.
If you have noticed your canines more since your front teeth were whitened, or in photos under strong light, this natural difference may be part of the reason. Lighting and the camera can also affect how strong the contrast looks, as our article on ring lights and tooth shade explains.
Where the colour comes from
The colour of a tooth is not a single layer of paint. In a review of the research on tooth colour, Joiner (Journal of Dentistry, 2004) described it as the result of many factors together, including translucency, opacity, the way light scatters inside the tooth, surface gloss, the lighting and how the eye and brain read it. Whitening works below the surface. In a later review, Joiner (Journal of Dentistry, 2006) described peroxide diffusing through the enamel and lightening coloured molecules, particularly within the dentine. Our article on how whitening works inside the tooth goes through that process step by step.
Exactly why canines measure more saturated than incisors has not been settled in the studies we reviewed. What is consistent is the measured result: on average, the canine is the deepest coloured of the upper front teeth.
Canines whiten, but may change less than the incisors
Whitening still works on canines. The question is how much they change. Esteves and colleagues (Quintessence International, 2024) followed 10 patients through three 45-minute in-chair sessions with 35% hydrogen peroxide and measured each tooth group separately. Upper and lower incisors showed a greater colour change than the canines and upper first premolars, and the lower incisors reached their limit of change sooner than the canines and premolars. The incisors also had the most sensitivity. This was a small case series, so it shows a pattern rather than a precise figure.
Joiner's 2006 review gives the general principle behind this: the two main things that drive whitening are the strength of the gel and the time it is in contact with the teeth, and lower strengths can approach the result of higher ones when used for longer. Starting colour also affects the outcome. Teeth that start out more saturated, as canines usually do, may have further to go.
What that means for a whitening plan
Because canines may lag, giving them more contact time over a course of whitening can help. This is one reason in-chair whitening on its own usually does not get people all the way, as covered in our article on why in-chair whitening alone is not enough. Every Lumi whitening option includes Boutique take-home whitening, which gives slower teeth more nights of contact. Lumi Home is take-home whitening with custom trays, with an overnight gel for sensitive teeth and a daytime gel for teeth that are not sensitive.
Some practical points:
- The incisors may look finished before the canines do. Stopping as soon as the front teeth look good may leave the corners behind.
- Your dentist may suggest continuing on the canines for a few more nights while the incisors rest, particularly if the incisors are becoming sensitive.
- A canine that ends up slightly deeper than the central incisors is common in natural smiles. Aiming for every tooth to be identical may look less natural, which is discussed in our article on choosing a natural shade.
Lumi does not promise a particular shade. How far each tooth moves depends on things such as its starting colour and the type of staining, which a dentist can assess before whitening begins.
When a dark canine is a different problem
The pattern described here applies to both canines being a little deeper than the incisors. One canine clearly darker than the canine on the other side, a grey or bluish tone, or a canine with a large filling or past injury is a different situation and worth having checked before any whitening. Fillings, crowns and veneers also do not respond to whitening in the same way as natural teeth. Our guides to one tooth more yellow than the others and grey teeth cover those causes, and lower canines are discussed in our article on why lower teeth look darker.
Common questions about canine colour
Will my canines ever match my front teeth?
They can lighten with whitening, but in many people they stay a little more saturated than the central incisors, just as they were before. The measurement studies above suggest some difference is natural rather than something left unfinished.
Is it worth whitening if my canines are what bothers me?
It can be. Whitening can lighten all the natural teeth, and the canines may take longer, so a take-home course gives them more time. If the canines are much darker than expected for their type, or have fillings, a dentist can check the cause first.
Planning your whitening
If your canines are the teeth you notice most, the team at Lumi Dental in Melrose Park can check them and talk through a plan that allows for them. See our teeth whitening page for how each option works.
Sources
- Pustina-Krasniqi T, Shala K, Staka G, et al. Lightness, chroma, and hue distributions in natural teeth measured by a spectrophotometer. Eur J Dent. 2017;11(1):36-40. PubMed 28435363
- Falcone ME, Kelly JR, Rungruanganut P. In vivo color relationships between the maxillary central incisors and canines as a function of age. Int J Prosthodont. 2016;29(5):496-502. PubMed 27611756
- Esteves LMB, Souza-Costa CA, Honma CM, et al. Clinical evaluation of different types of teeth in in-office whitening. Quintessence Int. 2024;55(10):804-812. PubMed 39302115
- Joiner A. Tooth colour: a review of the literature. J Dent. 2004;32 Suppl 1:3-12. PubMed 14738829
- Joiner A. The bleaching of teeth: a review of the literature. J Dent. 2006;34(7):412-9. PubMed 16569473
This article is general information only and is not a substitute for advice about your own situation from a dentist.
