A toothbrush was a device used for cleaning teeth. The Minyans invented the toothbrush after they rose up against the Time Lords. (TV: Underworld)
The Second Doctor told Jamie McCrimmon that it was a big step forward when humans invented the toothbrush. He confessed he shared a cell with William Addis (the accredited inventor of the toothbrush on Earth). (PROSE: The Time Eater)
The Fourth Doctor told Richard Dunbar that he was leaving immediately for Antarctica, telling him he might as well and that he had his toothbrush. (TV: The Seeds of Doom)
Jobel once threatened that anyone within Tranquil Repose who didn't act with the upmost respect and decorum during President Vargos's visit would spend the next month scrubbing out the preparation room with a toothbrush. (TV: Revelation of the Daleks)
Evelyn Smythe brought her toothbrush with her on her initial trip in the TARDIS. (AUDIO: The Marian Conspiracy)
When pretending to be Time Lords, Charley said that the Eighth Doctor's punishment for changing time was to clean out the TARDIS with a toothbrush. (AUDIO: Living Legend)
The Tenth Doctor lent Martha Jones his toothbrush when she complained as to lacking one. It contained Venusian spearmint within the bristles. (TV: The Shakespeare Code)
Amelia Pond packed a toothbrush in her suitcase when the Eleventh Doctor invited her to travel with him. (TV: The Eleventh Hour)
When ReThinx changed history with the Continuity Cap, sonic screwdrivers became sonic toothbrushes. (COMIC: The Continuity Cap)
The Eleventh Doctor accidentally picked up an electric toothbrush instead of his sonic screwdriver when he rushed to help Craig Owens. (TV: The Lodger)
The Eleventh Doctor later took possession of Albert Einstein's toothbrush. The Daleks exterminated it. (TV: Death is the only Answer)
One incarnation of the Doctor wore a toothbrush in his breast pocket. (COMIC: Party Animals)
Birdie asked Darius Pike if he could use his toothbrush, but Darius pointed out that, being a robot, Birdie didn't have any teeth. (TV: Mutant Copper)