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Most tooth powders contain no fluoride. That is not a small detail: fluoride's effect on tooth decay is one of the best-established findings in preventive medicine, and it works by converting enamel hydroxyapatite into more acid-resistant fluorapatite while interfering with bacterial metabolism.

A fluoride-free powder cleans. It does not do the thing that most reduces cavities. Anyone using one should be clear that they are trading caries protection for packaging, and — if caries risk is a concern — should discuss it with a dentist rather than assume the powder is equivalent.

Fluoride-containing tooth powders exist and are OTC drugs in the US, with a Drug Facts panel and an expiration date, exactly as toothpaste is.

Class	Doing what	Names
Abrasive	The cleaning	Calcium carbonate, hydrated silica, bentonite or kaolin clay
Alkali	Neutralises acid; mild abrasive	Sodium bicarbonate
Salt	Mild antibacterial, traditional	Sodium chloride
Flavour	Palatability	Peppermint, spearmint, clove, cinnamon
Sweetener	Taste	Xylitol — which has genuine anticaries evidence of its own
Sometimes	Charcoal, hydroxyapatite, essential oils	See below

Xylitol is the ingredient worth noting positively. It is not metabolised by Streptococcus mutans, and there is reasonable evidence for a caries-reducing effect — which makes it the most defensible non-fluoride active in the category.

Nano-hydroxyapatite is the other. It is used as a fluoride alternative, particularly in Japan, with a plausible remineralisation mechanism and a growing but less comprehensive evidence base than fluoride.

Charcoal tooth powders are the concern in this category. Dental professional bodies have repeatedly cautioned against them: the evidence for whitening is poor, many are highly abrasive, and enamel does not regenerate. Charcoal particles also lodge in gum margins and around restorations, and charcoal may bind and reduce the availability of fluoride where both are present.

Abrasivity is measured as RDA — Relative Dentin Abrasivity — with 250 as the regulatory ceiling. It is not printed on packaging, and homemade or artisanal powders have no RDA value at all. A gritty powder used twice daily with a hard brush and heavy pressure causes real, permanent wear and gum recession.

Damp the brush, tip a little powder into the palm or a dish and dip — do not dip a wet brush into a shared jar, which contaminates it. Brush gently, two minutes, soft bristles, light pressure. Spit, don't rinse, if the powder contains fluoride or hydroxyapatite.

Cosmetic in the US — FDA primary category (11) oral products — for a fluoride-free powder making cleaning and freshening claims. OTC drug under the anticaries monograph for anything with fluoride and a cavity-prevention claim.

A claim to whiten by removing surface stain is cosmetic; a claim to treat gum disease or sensitivity engages other monographs and is a drug claim.

In the EU, toothpastes and powders are cosmetics, with fluoride restricted under Annex III to a maximum of 0.15% (1,500 ppm) in oral hygiene products, and a mandatory children's warning between 0.1% and 0.15%.

Two to three years or more. A dry powder has essentially no microbial risk, and its only enemy is moisture — which, in a bathroom, is unavoidable if the jar is left open or a wet brush goes into it.

Keep it sealed, dip with a dry spoon or tip into the palm, and discard anything caked. Fluoride versions carry a printed expiration date and it means what it says.

• Oral Care — the shelf this sits on, and the rest of it.
• Cosmetics — what the label is legally allowed to say, and the full catalogue.
• The rest of Dentifrices — Toothpaste · Toothpaste Tablets · Whitening Toothpaste.
• Regulatory statements here follow the FDA and EU sources listed on Cosmetics, read 16 August 2026.