Introducing the VieBeauti Whitening Pen. Amazon's got a three-pack on sale for only $12 when you apply the on-page coupon.

The pen uses a brush tip applicator. Simply twist the bottom to release the gel into the brush, spread it on your teeth, and ...

Make up a plausible person to represent each of these types. This method was not concepted at the BBC. If you know the creator please contact the GEL team ...