Did you floss this morning? There's good news and bad news.
The bad news: you probably shouldn't have bothered.
In fact, flossers needlessly frittered away more than 12 hours rubbing dental tape around their enamels last year, new research suggests.
Work that out over your lifetime - if you can bear it.
The benefits of flossing as a means of preventing everything from tooth decay and cavities to pancreatic cancer have been drilled into us (sorry) since childhood, but an investigation by the Associated Press suggests those claims are bunkum.
Evidence for flossing is "weak, very unreliable," of "very low" quality, and carries "a moderate to large potential for bias," AP says, on examination of 25 studies that compare using a toothbrush alone versus using a brush and floss.
"The majority of available studies fail to demonstrate that flossing is generally effective in plaque removal," says one 2015 review, while another study cites "inconsistent/weak evidence" for flossing and a "lack of efficacy."
These studies were conducted in the US, where stereotypes would suggest teeth are straighter, whiter and generally more attractive than in Britain, but the British Dental Association agrees that flossing is largely "ineffective".
The BDA says the daily bathroom ritual is of "little value" unless the spaces between your teeth are too tight for the brushes to fit "without hurting or causing harm".
Health officials in the US have stopped recommending that people floss and NHS guidelines, which currently recommend flossing once a day, are set to be reviewed in January.
It's important to tell people to do the basics. Flossing is not part of the basics.
- Damien Walmsley, scientific adviser to the BDA
The BDA suggests inter-dental brushes as an alternative for dislodging food debris.
And the good news? An extra two minutes in bed a day is yours from now on.
Can't tear yourself away from the waxy wheel? Die-hard flossers are advised to do it in a sawing motion, not up and down the sides of the teeth.