How to brush your teeth properly, and the habits that undo it

Brushing is one of those things almost everyone does twice a day for decades without ever being taught properly, and the most common corrections people make on their own — brushing harder, brushing longer, brushing more often — are either useless or actively harmful.

This is general information rather than advice for your particular mouth. If something here conflicts with what your own dentist has told you about your teeth, theirs is the version that counts.

Two minutes, and it is longer than you think

Two minutes is the consistently recommended duration, and almost everyone under-estimates it badly — people asked to brush for two minutes typically stop at around forty-five seconds while believing they have done far longer. This is the single strongest argument for a timer, and it is why a timer changes outcomes more than most of the features that cost money, as covered in what actually matters on an electric toothbrush.

Split the mouth into four quadrants and give each thirty seconds. A brush that pulses at thirty-second intervals is doing this for you.

The angle is the technique

Hold the bristles at roughly 45 degrees to the gum line, not flat against the tooth. Plaque accumulates in the crevice where tooth meets gum, and a brush held flat skates straight over it.

Use short strokes, or small circles, or simply hold an electric brush in place and let it work — with an electric brush the motion is the brush's job, and scrubbing it back and forth defeats the mechanism you paid for. Move it tooth by tooth and let it sit for a couple of seconds on each.

The surfaces almost everyone misses

Consistently, and in this order: the inside of the lower front teeth, where the brush is awkward to angle; the back of the last molars, which requires deliberately opening less rather than more, because a wide-open jaw tightens the cheek; and the gum line itself, which follows from the angle above.

A useful habit is to start somewhere different each time. People who always start at the same place brush that area best and the final quadrant worst, every time, for years.

Pressure: less than you are using

Hard brushing does not clean better. Plaque is soft and comes away with minimal force; what extra pressure removes is enamel at the gum line and, more commonly, gum tissue itself. Gum recession does not grow back, and the sensitivity that follows is permanent.

The tell is a brush head that splays outward within a few weeks. If yours does, you are pressing far too hard, and that is worth more attention than which brush you own.

The one thing to stop doing afterwards

Do not rinse your mouth with water after brushing. Spit out the excess and leave it.

Rinsing washes away the concentrated fluoride that has just been applied, which is the part of toothpaste actually doing the protective work. Spit, do not rinse, is the single easiest improvement available and the one most people have never heard.

The same applies to mouthwash immediately after brushing — most rinses contain less fluoride than toothpaste, so using one straight afterwards dilutes what you have just applied. If you use mouthwash, use it at a different time of day.

Timing, and the acid trap

Brushing straight after anything acidic — citrus, wine, fizzy drinks, and in particular after being sick — brushes softened enamel and removes it. Wait about thirty minutes. Rinsing with plain water in the meantime is fine and helps.

Night brushing matters more than morning brushing, because saliva flow drops during sleep and saliva is what neutralises acid. If one session is ever going to be the more thorough one, make it that one.

What brushing cannot do

No brush reaches between teeth, and that is where a large share of decay begins. Interdental brushes or floss do a job a toothbrush cannot, and doing it once a day is worth more than any upgrade to the brush itself.

Replace the head every three months, or sooner if the bristles splay. A splayed head cleans measurably worse, and it is also telling you about your pressure.