Illustration by Daria Krikunova
Smooth, white teeth greet us from almost every billboard we see, on highways and metro stations alike. “Pearly whites” are usually taken as synonymous with top-notch oral health, even if they technically aren’t.
This is why teeth whitening treatments are a common way to round-up more extensive cavity or orthodontic treatments, or even to prepare for a major life event. However, enlisting a professional dentist to whiten your teeth can be very expensive, and few insurance plans cover it.
Naturally, this has led the markets to respond with an ever wider-variety of at-home or over-the-counter alternatives. But are they a good investment? And more importantly, are they safe?
How whitening products really work?
Your teeth are covered by a relatively thin layer of enamel, which is a hard, protective shell made mostly from calcium and phosphate (1). Most often, enamel starts as white, but life, long use, and dietary choices can stain the top of this crystallized calcium, turning it yellowish or even brown. Plaque and bacterial overgrowth can also soften/erode or damage your enamel, creating dark or discoloured spots.
If you’re interested in returning to brighter times, you can choose between two main routes: professional whitening treatments performed by a dentist, or over-the-counter alternatives that you can use at home. The latter include DIY remedies, whitening toothpaste and natural remedies, and rely mostly on the same principle: they scrub off the outer layer of enamel, to get rid of the stained sections and uncover a fresher-looking section (2).
At its thickest, your enamel layer is only 2.5 mm wide. Using whitening treatments excessively could scrub off too much, and leave the enamel thin and fragile or even expose the underlying dentin making the tooth vulnerable and sensitive.
At-home teeth whitening
If you are dead-set on trying to whiten your teeth at home, you have quite the variety of methods and active ingredients at your disposal. The fastest, most reliable, and safest results are generally reserved for professional treatments. On the other hand, any at-home solutions will require you to compromise between a slow and steady approach and an overly aggressive one that could cause lasting damage to your enamel.
Natural remedies – are they a good bet?
Many natural teeth whitening methods use common household ingredients, such as baking soda or apple cider vinegar. For the most part, they offer pretty modest results and it may take up to six weeks for you to notice any changes.
Unfortunately, this doesn’t mean that they are completely risk-free. Apple cider vinegar does have a tiny bleaching effect, but its high acidity can damage your gums and erode your enamel (3). Baking soda scrubs are actually harsher than commercial whitening toothpaste, and so they are more likely to damage your teeth than approved remedies.
Your local pharmacy options
A safer route is to use special whitening toothpaste or mouthwashes. These usually have added ingredients. Most often, these are either small abrasive particles that will remove the top discolored layer of enamel, or baking soda to slowly lighten it.
They are only slightly more expensive than regular toothpaste and can be easily integrated into your daily oral hygiene routine. Don’t expect any radical changes, however: it can take up to three weeks for your teeth to lighten up by a full shade (4).
Teeth whitening gels and strips
Over the past years, many teeth whitening gels, strips, and trays have appeared at normal drugstores, promising rapid whitening for a special occasion. Many of these products advertise themselves as using the same active ingredients as professional whitening treatments do, such as hydrogen peroxide or carbamide peroxide.
These are pretty strong bleaching agents that can easily damage your gums. Most European countries only allow very tiny concentrations of hydrogen and carbamide peroxide on over-the-counter products – which tend to be too low to be truly effective (5).
Charcoal mouthwash - playing with fire
Charcoal products are now a popular sight on beauty aisles. Many new organic labels advertise its “detoxifying” properties as part of their facial soaps and masks. This has now expanded onto the dental care aisle: charcoal-based mouthwash often markets themselves as natural alternatives to lighten teeth, combat poor breath and prevent cavities.
Unfortunately, the existing evidence doesn’t always agree with the labels. A review study published this year showed that charcoal products don’t really offer noticeable whitening effects, and don’t help consistently with halitosis. Moreover, many of these brands advertise themselves as “all-natural” and forego added fluoride, which makes them a poor replacement for regular mouthwash (6).
What can a professional treatment offer instead?
Undoubtedly, the safest and most expensive alternative for teeth whitening is to get a professional treatment by your dentist. First, he or she will check the extent of the damage to your enamel, which will help them determine if you are a good candidate for a teeth-whitening treatment.
Depending on the state of your teeth, your whitening treatment can be done in one sitting or several sessions. He or she will use hydrogen or carbamide peroxide as the main ingredient, and either let it act for a controlled time, or speed up its action with halogen or LED lights. That being said, the final word is still not out on whether these lights offer any extra benefits (7).
Dentists can also provide you with a custom-fitted tray or night guard for you to take home. These will be moulded to the shape and size of your teeth, which will make it less likely for your gums to come into direct contact with the bleaching agent.
Plus, your regular dentist can also easily spot any underlying reasons for stained or discoloured teeth (such as ongoing cavities). Afterwards, you may need to avoid future stains by curbing your intake of staining foods – such as tea and red wine, which are high in tannins.
Teeth whitening treatments don’t just differ in their price labels: they also come with very different degrees of effectiveness and safety ratings. If you want to get predictable results with little chance of side effects, steer clear from any home ingredients or overpromising charcoal-based treatments. Stick to your dentist’s professional advice, and keep your oral hygiene routine steady.
1. Bowes, J. H., & Murray, M. M. (1935). The chemical composition of teeth: The composition of human enamel and dentine. The Biochemical journal, 29(12), 2721–2727. Available online at https://doi.org/10.1042/bj0292721
2. Carey C. M. (2014). Tooth whitening: what we now know. The journal of evidence-based dental practice, 14 Suppl, 70–76. Available online at https://doi.org/10.1016/j.jebdp.2014.02.006
3. Rutala WA, Barbee SL, Aguiar NC, Sobsey MD, Weber DJ. Antimicrobial activity of home disinfectants and natural products against potential human pathogens. Infection Control & Hospital Epidemiology. 2000 Jan;21(1):33-8. Available online at https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/antimicrobial-activity-of-home-disinfectants-and-natural-products-against-potential-human-pathogens/6D70C6F5E3928DDB3365FB9AF7CCD8E9
4. Li, Yiming (2017) Stain removal and whitening by baking soda dentifrice. Journal of the American Dental Association, Volume 148, Issue 11, S20 - S26. Available online at https://doi.org/10.1016/j.adaj.2017.09.006
5. Demarco, Flávio Fernando, Meireles, Sônia Saeger, & Masotti, Alexandre Severo. (2009). Over-the-counter whitening agents: a concise review. Brazilian Oral Research, 23(Suppl. 1), 64-70. Available online at https://dx.doi.org/10.1590/S1806-83242009000500010
6. K. Brooks, J., Bashirelahi, N. & Hsia, R. Charcoal-based mouthwashes: a literature review. BDJ Team 7, 22–27 (2020). Available online at https://doi.org/10.1038/s41407-020-0294-0
7. Baroudi, K., & Hassan, N. A. (2014). The effect of light-activation sources on tooth bleaching. Nigerian medical journal: journal of the Nigeria Medical Association, 55(5), 363–368. https://doi.org/10.4103/0300-1652.140316. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4178330/