Toothpaste and mouthwash

A toothpaste is essentially a carrier for fluoride and a mild polishing agent. Everything else — flavour, foam, colour, advertising promises — changes little about the outcome. Two pieces of information on the tube are meaningful, and both are printed small.

The fluoride content

It is given in ppm, parts per million. The values that matter:

• Adults and adolescents: 1,000 to 1,500 ppm. That is the range for which the effect against caries is established.
• Children up to the second birthday: a rice-grain-sized amount of a toothpaste with 1,000 ppm.
• Children from two to six years: a pea-sized amount with 1,000 ppm.
• From six years: the adult concentration.

A toothpaste without fluoride leaves out the most effective ingredient. Anyone who chooses one out of conviction should know that they are thereby giving up the best-established protection against caries. Hydroxyapatite is advertised as an alternative; the first studies are not unreasonable, but the data do not come close to those for fluoride.

The abrasiveness: RDA

The RDA value indicates how strongly a paste removes tooth substance. It is rarely on the tube but can be found from the manufacturer or in comparisons. A rough guide:

• under 50 — low, for exposed tooth necks and sensitive teeth
• 50 to 80 — medium, for normal daily use
• over 100 — high, effective against discolouration, not for continuous use

Many whitening pastes are in the upper range. On enamel that is occasionally defensible; on exposed dentine at the tooth neck it is not — dentine is considerably softer and does not grow back.

Special pastes

• Sensitive: contain potassium nitrate, stannous fluoride or arginine, which dampen the transmission of stimuli within the tooth. They work, but they need time — two to four weeks of regular use.
• Whitening: remove what has been deposited through their abrasiveness. They do not bleach. The tooth does not become lighter than its own colour.
• For gums: often contain stannous fluoride or zinc compounds and can reduce the tendency to bleed. An interdental brush achieves more.
• Natural cosmetics: frequently without fluoride. Anyone using them should supply fluoride another way, for instance through a gel.

Mouthwashes: what they can do

A rinse does not reach plaque — it washes around it. The biofilm is an adhering layer with a protective coat of its own; it is removed mechanically or not at all. Hence the most important sentence on this subject: a mouthwash replaces neither brush nor floss.

As an addition it can be useful. Three groups are to be distinguished:

• Fluoride solutions for daily rinsing. Useful where the caries risk is increased, with braces and with exposed tooth necks.
• Cosmetic rinses with essential oils or zinc compounds. They can slow plaque formation slightly and make the breath fresher. Suitable for continuous use.
• Chlorhexidine — a medical antiseptic, not an everyday product. It acts strongly against bacteria and is used after operations, with acute inflammation and temporarily after periodontal treatment. With longer use it stains teeth and tongue brown and alters the sense of taste. Two to four weeks is usual, no longer — and not without a reason.

Alcohol in rinses serves no therapeutic purpose; it is a solvent. With a dry mouth, with children and with people who are dependent on alcohol, alcohol-free preparations are the right choice.

Oil pulling, home remedies, baking powder

Oil pulling is harmless if it is done in addition. There is no evidence that it prevents caries or gum inflammation. Anyone who does it instead of using dental floss swaps an effective measure for an unproven one.

Baking powder, bicarbonate of soda and salt are unsuitable for brushing teeth: too coarse, no fluoride. The advice to whiten with lemon juice or cider vinegar is harmful too — acid dissolves enamel, and the effect is permanent.