Frequently asked questions about toothpaste

RDA is the abrasiveness index: how actively a toothpaste removes plaque. The higher it is, the more effectively it removes stains — and the more careful you need to be with your enamel.

Reference points: up to 100 — safe for daily use; 25–50 — for sensitive teeth and exposed tooth necks; 120–140 — intensive whitening, short courses only.

For adults — 1350–1500 ppm. Below 1000 ppm, studies show no convincing anti-caries effect. For children, the dosage depends on age: from a “smear” of 500 ppm paste at 0–2 years to the adult concentration after age 12. For details, see the article “Fluoride: myths and facts”.

No. Foam is the work of surfactants (most often SLS), not an indicator of cleaning power. Toothpastes with mild surfactants (Poloxamer 188, cocamidopropyl betaine) foam less but clean just as well — and are less irritating to the mucosa. They are often chosen for dry mouth and a tendency to aphthous stomatitis.

The question itself is misleading: they work differently and complement each other. Fluoride strengthens enamel chemically and is proven as a means of caries prevention; hydroxyapatite physically fills microdefects and tubules. The best option is a toothpaste that contains both. See the full explainer in “Hydroxyapatite and fluoride”.

Two minutes, twice a day. Evening brushing matters more than morning brushing: less saliva is produced at night, so plaque works on the enamel unhindered.

An important detail: after brushing, do not rinse your mouth with water — just spit out the excess. This way fluoride stays on the enamel longer.

Daily-care toothpastes do not need to be alternated. But “course-use” toothpastes — with a high RDA or with an antiseptic — are by definition not meant for continuous use: after the course, return to a preventive toothpaste.

A common working scheme when you have several needs: one toothpaste in the morning, another in the evening — for example, one for sensitive teeth in the morning and one for gums in the evening.

Every 3 months — or sooner if the bristles have splayed out. Deformed bristles remove plaque less effectively and injure the gums. Be sure to change your toothbrush after an infection.

A mouthwash does not replace brushing — it complements it, reaching where the bristles could not. It makes the most sense for those prone to gum inflammation and for people wearing braces or dentures. For healthy teeth with good hygiene, toothpaste plus dental floss or interdental brushes is enough.

First of all — do not stop brushing. The most common mistake: a person sees blood, starts sparing the area, plaque builds up, and the inflammation grows.

Next: switch to a soft toothbrush, add a gum-care toothpaste as a course and — without fail — see a dentist. Bleeding gums often mean tartar, which no toothpaste can remove: professional cleaning is needed. If your gums bleed for longer than 2–3 weeks, do not put off the visit.

This is usually hypersensitivity caused by worn enamel or an exposed root. What helps: a toothpaste with a low RDA (25–50) and desensitizing ingredients — potassium salts, hydroxyapatite. The effect builds up over 2–4 weeks of regular brushing, not from the first use.

What not to do: brush with force or pick a whitening toothpaste with a high abrasive — that will make the problem worse. If the pain is sharp and long-lasting, it may be caries or a crack — see a dentist.

In about 85 % of cases the source is in the oral cavity: coating on the tongue, inflamed gums, carious cavities. Start with cleaning your tongue with a scraper and a check-up at the dentist.

Among toothpaste ingredients, zinc compounds help — they bind the volatile sulphur compounds that cause the odour. If the odour remains after your teeth and gums have been treated, it is worth checking the ENT organs and the digestive tract.

A toothpaste removes deposits on top of the enamel — from coffee, tea, tobacco. It cannot change the natural shade of the enamel itself: that requires procedures at the dentist.

If your teeth are naturally “yellowish”, that is normal — the dentin showing through the enamel is to blame. Healthy enamel is in fact translucent, and a perfectly white tooth is a rarity.

Before age 12 — better not. The reason is the fluoride concentration: the adult 1450–1500 ppm assumes the paste is spat out completely. Young children swallow part of the paste, and until the permanent teeth have formed (up to about age 8), excess fluoride can affect the enamel.

Kids' toothpastes are not “the same thing with a picture on the tube”: they have their own age-appropriate concentration and mild surfactants. See the age-based range in the kids' section.

With the first tooth — usually at around 6 months. Start with a silicone finger brush or a soft baby toothbrush, with a “smear” of toothpaste. Baby teeth are even more prone to caries than permanent ones: their enamel is thinner.

A child is able to clean their teeth properly on their own by about age 7–8 — until then, an adult must always “finish up” the brushing.