Dental cleaning sessions last two minutes, divided into four 30-second segments, one for each corner of your mouth.
Shown off on the opening day of the four-day Mobile World Congress in Barcelona, Spain, the brush is connected by Bluetooth wireless technology to your smartphone, and thus to the network.
"It is a world first," said Michael Cohen-Dumani, head of Procter & Gamble's Oral-B brand, which plans to sell the product in Europe, the United States and Asia from June.
Sold for 219 euros ($300), the brush relays your toothbrushing activity to an application on the smartphone, recording whether you respect the two-minute rule and whether you brush hard, but not too hard.
If the results are satisfactory, a message appears on your smartphone: "Congratulations: your teeth are shining."
It also lets you share the information on social networks or directly with your dentist.
"Today we can see the smartphone's potential to change people's habits," Cohen-Dumani told AFP.
"It is really that trend towards the 'quantified self'", the desire to record everything, to follow your sports activities, the calories you consume or what you spend, thanks to new technologies.
The world's largest mobile fair is a showcase for that trend, with smartphone markers unveiling an array of smart watches and bracelets that can count your steps or track your heart rate, and even wifi-connected scales to keep an eye on your weight.
Larger objects, too, are getting hooked up to the network, from cars and fridges to a shop dressing room that lets you ask for new sizes and colours to try on without leaving the cabin.