eli5 why does putting toothpaste on scratched disks fix them?

Question

As the title says why does toothpaste fix disks

In: 2049

Answer 1

You’re just polishing out the scratches. Any mild abrasive could accomplish the same thing….toothpaste is common enough that everybody has it, and it’s mild enough that people can use it on their teeth for a lifetime, so there’s little chance it’ll cause more harm than good on a disk. If you got a really scratched up disk, you can use Brasso instead of toothpaste…it’s more aggressive, but still doesn’t have any kinda chemicals in it that will damage the plastic.

The actual shiny part of a disk is what holds the data..the plastic just protects it.