Brushing and flossing, without the sermon

The night one matters more. Saliva flow falls while you sleep, and saliva is what neutralises acid and washes away debris. Plaque left on at bedtime sits undisturbed for eight hours in a mouth with the defences turned down.

Two minutes is longer than it feels. Almost everyone who times themselves for the first time discovers they were brushing for forty seconds.

This is the single most common correctable mistake. Spit out the excess toothpaste and stop there. Rinsing with water — or with mouthwash — washes away the concentrated fluoride you just applied, which is the part doing the work.

If you use a fluoride mouthwash, use it at a different time of day, not straight after brushing.

Decay and gum disease both start where the tooth meets the gum, which is precisely the strip most people brush past. Point the bristles at about forty-five degrees into that junction and use small movements rather than long scrubbing strokes.

Soft bristles. Hard-bristled brushes and heavy pressure do not clean better; they wear the tooth surface at the neck and push the gum back, and that recession does not grow returned.

Enamel is temporarily softened by acid — citrus, wine, cola, vinegar dressings. Brushing straight afterwards scrubs at a softened surface. Wait around an hour, or rinse with plain water and brush later.

A toothbrush cannot reach it. That is not a flossing-industry talking point, it is geometry — which is why cavities so often appear between teeth in people who brush diligently.

Floss, tape, interdental brushes or a water flosser: the best one is the one you will actually use daily. Interdental brushes tend to be more effective than floss where the gaps are large enough to take them. Ask which size fits you — it is not one size.

Oscillating-rotating and sonic brushes generally remove more plaque than manual brushing, mostly because the built-in timer and pressure sensor correct the two things people get wrong. A manual brush used properly for two minutes beats an electric one used for thirty seconds.