Doing it wrong

Everyday habits that are backwards, and what to do instead.

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The Bacteria On It Are Already Yours

Millions of bacteria on your toothbrush, almost all of them already yours. The toilet worry is misdirected, and what matters is whether the brush dries.

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Five Reasons, and Only One Is the Dentist

Almost never bad luck. There are five reasons and they point at different fixes, one of which is that the tooth has run out of the structure a filling needs.

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Some People Really Do Have Harder Mouths

More than people are told, and less than they fear. Genetics sets how much margin you have, and the same routine produces different results because of it.

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Plaque Is Yours. Calculus Isn't.

No. Plaque and tartar are two different substances, and one dentist explained where the line falls in a way nobody who reads it forgets.

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The Motor Is Not Why It Wins

Yes, by a measurable but modest margin — and the reason has less to do with the motor than with the two minutes the timer makes you stand there.

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The Order Nobody Told You Mattered

The profession doesn't fully agree, and most people have never heard the question. There is a reason to floss first, and it has nothing to do with tidiness.

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The Number Nobody Puts on the Box

People ask this constantly and get no real answer. It's the only number that decides whether anything in your mouth works, and nobody prints it on a box.

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It Depends What You Ate, Not That You Ate

Thirty minutes, but only after acidic food and drink. For most meals the advice is over-applied, and there is something better to do in the meantime.

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The Clock Your Mouth Restarts Every Time You Eat

Enamel starts dissolving below a certain acidity, and every time you eat the clock restarts. A chocolate bar at once beats a drink sipped for three hours.

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What the Flossing Evidence Actually Says

In 2016 reporters asked for the evidence behind the flossing recommendation. It couldn't be produced, and flossing quietly left the US guidelines.

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You're Washing the Toothpaste Off Before It Works

Two minutes of brushing, then ten seconds at the tap undoing most of it. The rinse is the most common self-inflicted mistake in oral care.