The American Dental Association suggests that everyone replace their toothbrushes every three or four months. At that rate, brushers in the U.S. alone would go through over one billion toothbrushes each year. And if everyone around the world followed those recommendations, about 23 billion toothbrushes would get trashed annually. Most are traditional toothbrushes, but some 55 million U.S. brushers use electric toothbrushes each year, so some number of those plastic-handled, battery-containing objects also end up in the waste stream each year.
Source : https://www.nationalgeographic.com/environment/2019/06/story-of-plastic-toothbrushes/