We've all had that depressing moment during a regular check-up when the dentist says "Ah. I've found something here to keep an eye on. Doesn't need a filling yet, but you'd better start flossing more carefully there, and we'll assess it again in a year".
And then, despite your best tooth-care efforts over the next 12 months, at your next appointment it's time to rev up the drill and that nasty needle is heading for your gums.
Our teeth are constantly losing and regaining the calcium-based mineral that's the main component of tooth enamel.
After we eat, the acid in our mouths starts the demineralisation process.
Once the mouth acid has dispersed, the mineral loss is reversed as our teeth take up calcium from our saliva. Cavities start when the rate of demineralisation gallops ahead of the remineralising repair work.
Now dentists are already proficient at spotting where this is happening, and there are already remineralisation techniques available like prescribing ultra-high fluoride toothpastes or fluoride varnishes to protect the teeth.
But there's a limit to what products that are smeared onto the teeth can achieve.
They are good at repairing the tooth surface, but that just seals in the deep down damage, ready to develop into tooth decay as soon as the surface is breached again.
The innovation that scientists at King's College London hope will revolutionise dentistry is a two step process - to first clean and condition the damaged outer layer of the tooth, then use a tiny electric current to "push" minerals directly into the repair site.
The action of the electricity makes the tooth remineralise from the inside outwards, rather than just at the surface. And the process is hugely accelerated compared to just waiting for molecules to move into a tooth on their own.
That's why Electrically Accelerated and Enhanced Remineralisation, or EAER, is being described as a "step-change" in decay prevention.
The researchers hope to have a marketable product within three years, and their target is to match the cost of EAER treatment to the cost of a conventional filling.
They believe it could eventually get rid of the need to fill even modestly sized cavities, but I'm afraid if you delay that trip to the dentist until you've got a massive painful hole in your tooth, it'll still be the drill for you.