An Englishman named William Addis is usually credited with inventing the modern toothbrush in 1780, while he was in prison. He drilled holes in a small bone, threaded clumps of stiff pig bristles through and glued them in. Until then, most people had been chewing on twigs to clean their teeth - and many cultures still do.
For the next 150 years, toothbrushes had pig bristles or sometimes horse or badger hair. They were expensive, scratchy and got mouldy because they never really dried out. Then in 1938 the chemical company DuPont invented nylon. Suddenly bristles could be made of cheap plastic strands that were soft, springy and dried quickly.
The first electric toothbrush arrived in 1954 from a Swiss inventor. It needed to be plugged into the wall. Today’s battery-powered versions can buzz at over 30,000 strokes a minute. But the basic idea - bristles on a stick - hasn’t really changed since a 1780 prison cell.
