Brushing teeth properly

Brushing teeth involves less rubbing than ordering. The cleaning performance depends hardly at all on the force applied and almost entirely on whether every surface was touched at all. Anyone who brushes without a system reliably leaves out the same places — usually the inner surfaces of the lower molars and the back of the rearmost teeth.

The system

A set of teeth has three kinds of surface that have to be brushed: outer, inner and the chewing surface. Anyone who works through them in a fixed order forgets nothing. It has proved useful to divide the mouth into sections — upper right, upper middle, upper left, then the same below — and to brush each section on all three surfaces before moving on to the next.

Start regularly at the same place, but not always at the same one: experience shows that the sections brushed last receive less attention. Changing the starting point every week spreads the carelessness around.

The movement

For manual toothbrushes the rule is: the bristles are placed at an angle of about 45 degrees at the junction between tooth and gum, pressed lightly and then wiped out from gum to tooth with small shaking movements — from the red to the white. Large horizontal scrubbing movements are what exposes tooth necks.

The pressure should be such that the bristles only bend slightly. A rule of thumb: hold the brush with three fingers like a pen, not with the fist like a handle.

With children: KAI

Children learn the order best through a memory rule: Kauflächen (chewing surfaces), Außenflächen (outer surfaces), Innenflächen (inner surfaces). First scrub the chewing surfaces, then the outside in circles, then wipe out the inside. That is coarser than the adult technique and suitable for exactly that reason — it is an instruction a six-year-old can remember.

Two minutes is a minimum

Two minutes is the established guide value, and most people underestimate how long two minutes are: without a clock, many brush for about 45 seconds. An hourglass, a timer or the timing function of an electric brush changes more about that than any good intention.

Anyone with many teeth, crowded teeth, dentures or a brace needs longer. Three minutes is then not excessive zeal.

Guiding electric brushes differently

An electric brush makes the movement itself. It is therefore not guided but held: place it on tooth after tooth, linger a few seconds, move on. Anyone who moves it back and forth like a manual brush cancels out its advantage.

Most models have a pressure control. It is not a gimmick but the most useful part of the device — it shows what you cannot feel yourself.

Do not forget the tongue

A considerable proportion of the bacteria in the mouth sit on the back of the tongue, especially in its rear third. It is the most common source of bad breath. Cleaning is done with a tongue scraper or the back of a toothbrush, once a day, with a gentle pull from back to front — not scrubbing, which irritates the mucosa.

The most common mistakes

• Too much pressure. The main reason for receding gums and exposed tooth necks.
• Horizontal scrubbing instead of wiping movements.
• Brushing straight after something acidic. Wait half an hour.
• No system. Without a fixed order, the same surfaces always stay untouched.
• Using the brush for too long. After eight to twelve weeks the bristles are bent; bent bristles clean less well and injure more easily. Change earlier after a cold.
• Rinsing vigorously. Rinses the fluoride straight back out again.
• Only brushing. Without interdental care a third of the surface stays untouched.