Is charcoal toothpaste a good choice for your teeth?

The short answer, and why

Charcoal toothpastes are sold on the promise of whiter teeth, fresher breath and a "cleaner" mouth. The published research does not support those promises. In 2017 the Journal of the American Dental Association published a literature review of charcoal and charcoal-based dentifrices. The authors searched the medical literature for clinical and laboratory studies and also looked at 50 charcoal toothpastes on the market. They found insufficient evidence to support the safety or effectiveness claims made for these products, judged the whitening, antibacterial and "detoxifying" claims unproven, and noted that only one of the 50 products they examined contained fluoride. Their advice to dentists was to counsel patients to be cautious.

That does not mean every charcoal paste will damage your teeth. It means the product is being chosen for benefits that have not been demonstrated, and that most versions leave out the one toothpaste ingredient with a strong record: fluoride. Toothpastes that carry the ADA Seal of Acceptance must contain fluoride and must fall at or below an established abrasivity limit, so the Seal is a quick way to see whether a product has been checked on both counts.

What charcoal can and cannot do to tooth color

Tooth color comes from two places. Surface (extrinsic) stain builds up on the enamel from coffee, tea, red wine, tobacco and some pigmented foods. The underlying color of the tooth itself (intrinsic color) sits inside the enamel and dentin and comes from genetics, age, past trauma, certain medications taken while the teeth were forming, and similar causes. The guide Why do teeth change color even when you brush them? explains this in more detail.

Surface stain versus the color of the tooth itself

Charcoal is an abrasive. Any abrasive toothpaste, charcoal or not, can polish away some fresh surface stain, which can make teeth look a little brighter for a while. That is the same mechanical effect produced by ordinary whitening toothpastes and by a professional cleaning. What abrasives cannot do is change the intrinsic color of the tooth. Changing that color usually calls for a peroxide-based bleaching agent, which oxidizes the pigments inside the enamel and dentin rather than scrubbing the surface, and some intrinsic discoloration does not respond to bleaching at all. The review of charcoal products found no clinical evidence that they bleach teeth in this way, and no study showing that they remove stain more effectively than a conventional paste.

If your teeth are stained on the surface, a charcoal paste may seem to work for the same reason any abrasive paste seems to work. If your teeth are yellow or gray throughout, no amount of scrubbing will change that, and more scrubbing can begin to remove enamel. The guide Does whitening work on every tooth and every kind of stain? covers which stains respond to bleaching and which do not.

What changes the answer for you

The general answer ("not a better choice") shifts depending on the product and on your mouth.

• Whether the product contains fluoride. Fluoride in toothpaste helps enamel take minerals back up after acid exposure and is the main reason toothpaste protects against decay. A charcoal paste without fluoride gives up that protection. If you are drawn to charcoal, the first thing to check is whether fluoride appears on the ingredient list; most of the products in the 2017 review did not include it.
• How abrasive the product is. Toothpaste abrasivity is measured on the Relative Dentin Abrasivity (RDA) scale. The ADA accepts values at or below 250 as safe and effective and requires that limit for the Seal of Acceptance. The ADA also says that values below 250 should not be used to rank one product as safer than another, so the number works as a pass-or-fail check rather than a ranking. If the maker does not publish an RDA value, the question cannot be answered from the label, and it is worth asking at your visit.
• Gum recession or exposed root surfaces. Where gums have receded, the exposed root has no enamel covering, so it is more vulnerable to both wear and decay. An abrasive paste used with firm pressure on these surfaces can speed that wear. If you have recession, see Choosing a toothbrush when your gums have receded and ask about abrasivity before trying any new paste.
• Veneers, bonding or crowns in the smile. Abrasives act on restorative materials as well as on tooth structure. A paste that is harsher than needed can dull the polished surface of composite bonding over time, and it will not whiten porcelain or composite at all, so a mismatch can develop between restorations and natural teeth. Ask your dentist which pastes suit the work you have.
• Sensitivity. Teeth become sensitive when dentin is exposed by worn enamel or receding gums. If you already notice twinges with cold or sweet, an abrasive paste may make them worse, and the cause of the sensitivity should be examined rather than masked.
• Your decay risk. If you have had cavities recently, have dry mouth, or snack on sugars through the day, giving up fluoride is a real cost. People at higher risk may need more fluoride, not less.

Claims you may hear, and what the evidence says

The practice does not claim that charcoal is harmful to everyone or that it is "toxic." The point is narrower: the claimed benefits have not been shown, and the usual trade-off is giving up fluoride.

What an examination determines

Marketing cannot tell you what kind of stain you have or how much enamel you have to spare. An examination can. At a check-up the dentist or hygienist can:

• Identify the stain type. Surface stain is usually removed during a professional cleaning. Discoloration that remains afterward is intrinsic and would need a peroxide method, a bonded restoration or no treatment at all, depending on the cause.
• Look for wear. Flattened enamel, notches near the gum line and exposed, shiny root surfaces suggest abrasion from brushing habits or paste choice, and are a reason to switch to a low-abrasivity fluoride paste and a soft brush.
• Check for recession and sensitivity. Exposed roots change the advice on both toothpaste and brushing pressure.
• Assess decay risk. Someone with active decay or a dry mouth has more to lose by dropping fluoride than someone with a long record of healthy check-ups.
• Discuss whitening properly. If a whiter smile is what you want, peroxide-based whitening, used as directed, has a documented record of working. Known side effects include temporary sensitivity and gum irritation, and whitening gels do not change the color of existing fillings, veneers or crowns, which is why the examination comes first. Professional whitening or strips: which option fits your teeth and goals? compares the approaches.

What good daily care looks like without charcoal

For most adults the evidence-based routine is simple: brush twice a day for two minutes with a soft-bristled brush and a fluoride toothpaste, using only enough pressure to remove the film from the teeth, and clean between the teeth once a day. Toothpaste carrying the ADA Seal has been checked for fluoride content and abrasivity. Whether to rinse right after brushing is a separate question; see Should you rinse your mouth right after brushing? for the reasoning.

The next step

If you are already using a charcoal paste and have no sensitivity, recession or recent cavities, there is no emergency, but it is worth bringing the tube to your next check-up so the ingredient list and abrasivity can be reviewed against your mouth. If you are considering charcoal because your teeth look dull or yellow, ask at your visit which type of stain you have before buying anything. Loul Dental Studio offers check-ups and cleanings and lists in-office whitening, custom tray whitening and combined approaches among its services; an examination shows which, if any, fits your teeth. You can request an appointment online (a request is not a confirmed appointment; the team follows up) or call (805) 565-5111 during office hours.