There are other uses for old toothbrushes [1], but I'm with you: I want the only parts that get tossed be the bristles themselves, ideally as a soil amendment (not as plastic nanoparticles that end up inside our food chain). It is very annoying plastics are used for only a tiny fraction of their lifecycles, and spend most of their lifecycle polluting our raw resources.
Interestingly, there is a company that rebristles antique brushes and also sells toothbrushes [2]. No idea if they rebristle toothbrushes.
Blizzident [3] sells an interesting product for $340, rebristles for $90, and you have to spend up to $200 to get a dental impression because the Blizzident is custom fit to each user [4]. Verified experience seems sparse on the ground [5], [6], and actual controlled study seems non-existent.
Interestingly, there is a company that rebristles antique brushes and also sells toothbrushes [2]. No idea if they rebristle toothbrushes.
Blizzident [3] sells an interesting product for $340, rebristles for $90, and you have to spend up to $200 to get a dental impression because the Blizzident is custom fit to each user [4]. Verified experience seems sparse on the ground [5], [6], and actual controlled study seems non-existent.
[1] https://experthometips.com/22-uses-for-used-toothbrush
[2] https://kentbrushes.com/bodycare/handmade-toothbrushes
[3] http://www.blizzident.com
[4] https://newatlas.com/blizzident-toothbrush/29264/
[5] https://www.reddit.com/r/Dentistry/comments/aco59q/product_r...
[6] https://www.youtube.com/watch?v=15JlKqoU4cI