One can only guess what William Addis would have made of the OralB CrossAction. In 1780, Addis, an enterprising Londoner with an interest in oral hygiene ahead of his time, became - historians believe - the first person to fasten hog bristles to a bone handle, creating the toothbrush as we know it. It wasn't much (and some archaeologists reckon the Chinese got there 700 years earlier), but it was a vast improvement on the twigs and rags people had rubbed against their teeth for centuries previously - even if the proto-toothpaste developed alongside Addis's brush, made by mixing brick dust or cuttlefish bone with water, did more harm than good.
The OralB CrossAction, on the other hand, is a resolutely 21st-century brush. Launched in the UK last week, it's the latest in a range of innovative brushes making ever-greater health claims. It's also a bit frightening to look at: multicoloured bristles of varying lengths lurch at crazy angles, surmounted by an alarming triangular prong of brush. The manufacturers say the design compensates for our failure to brush as we've been taught; users report that it feels like there's a carwash in their mouths (a description that OralB seem to take as a compliment, judging by its prominence in their advertising campaign).
The process of innovation that began with the introduction of nylon bristles in the 30s has reached a frenzied pace, and the innocent shopper now faces a nightmarish choice. Will it be a Reach Access, featuring bristles excitingly heat-sealed into the head and a "power tuft" sporting "10 times the usual number of bristles"? An Aquafresh Flex, Flex Tip, Flex Sensitive, Flexosaurus, Flex Generation or Flex Direct Triple Action? A Wisdom Orbital, with a tiny circular head on a grotesquely oversized handle? Or a Wisdom Ultraflex Bioguard, with an antibacterial cleanser built into the handle?
The Ozone toothbrush is the weirdest of the lot. It has an oval ring of bristles around a gaping hole which, inventor Jonathan Savitt maintains, flushes away bacteria that could otherwise fester amid the bristles and reinfect the user. Launched in the UK in September, it's already selling 120,000 a month in Italy, where it's manufactured; here, the Design Council recently awarded it Millennium Product status, and it will be on display in the Dome.
The toothbrush has been fashion accessory as well as health product since its earliest days, when the upper classes - for whom it was a symbol of wealth, demonstrating that they could afford to eat sugar - wore gold ones on chains around their necks. But in the light of the claims made for the current spate of oral hi-tech, one question has to be asked: is any of this really going to leave our teeth in a better state?
Aubrey Sheiham, professor of dental public health at University College London, is sceptical. "One has to weigh up these intricate design features against cost and durability," he says. "I've heard that the new generation of brushes wear out quickly, and the bristles start splaying. But there's clearly a middle-class market prepared to pay quite a few pounds for a brush."
Sheiham dismisses heat-sealed bristles and isn't convinced by the Ozone: "Hygiene isn't the major factor, simply because most brushes wear out after six weeks." But he admits to being a sucker for a clever design himself: he swears by Dent-O-Care's horseshoe-shaped Superbrush, which fits over the teeth and brushes all three sides at once.
Martin Addy, professor of periodontology and a member of the International Standards Organisation's toothbrush working group, which is currently planning a new global standard, insists: "The conclusions of international workshops have always been that there is no single superior brush design."
More worrying than such gimmicks, though, is the suggestion that some of the choices on offer may actually be bad for our teeth. The British Dental Association agrees with almost all dentists that the best brushes are those with small heads and soft to medium bristles. Yet manufacturers intent on providing a dizzying range of oral experience continue to offer hard-bristled and large-headed variations; and complex bristles usually need bigger heads, too.
Just as inadvisable are the animal-bristle brushes currently enjoying a revival: natural fibres, the BDA warns, are porous and more likely to harbour bacteria. And you can forget what you were told at school, Sheiham insists: the horizontal action most of us use is actually more effective than a circular one.
In fact, the key to a good brush is not to be found in the head at all, but in the handle. The BDA says an overly aggressive technique is the biggest problem in toothbrushing - and that hasn't been helped by the fist grip conventional brushes encourage. Sheiham recommends holding your brush as you'd hold a pencil, and here manufacturers have made some advances, with curved handles and non-slip grips. Just as effective, though, is a handle too short to make a fist around - something like a child's brush.
That said, no dentist in their right mind would condemn an attractive design if it leads you to view toothbrushing as a marginally less tiresome chore - especially if you happen to be a young child at the age when it's vital to cultivate the habit. "If it's easier to make a child brush their teeth because it's a bit fun, then that's important," says Sheiham. And not just children: should you happen to get bored during the "greatest show on earth" at the Dome, perhaps a brush with an intriguing hole will be all it takes to lure you into going and brushing your teeth instead.
