Scanning electron microscope: new vs. worn toothbrush bristles
Applied Science · Demo · 9 min · 2015 · YouTube title: Your toothbrush is worn-out!
Why it's here
HN commenters link it for electron micrographs of fresh versus worn bristles when toothbrush wear comes up.
What it covers
Ben Krasnow of Applied Science uses a scanning electron microscope to compare new and worn toothbrush bristles. He shows how the microscopic texturing wears down with use.