DH brushing 3yo teeth with adult paste

[Aintthatthetooth]

Just that really, turns out that DH has been putting adult Toothpaste on DS 3 toothbrush for over a month now. We have milk teeth Toothpaste in the house which he has been using for the 1 year old, but apparently everytime he's done morning or night teeth brushing over the last month or so he has been using adult Toothpaste on DS3. He said he thought he'd outgrown the baby one. To be clear, he still has all milk teeth, he's 3!
AIBU to think DH is a bit batshit for doing this and needs to stop immediately!?

It's fine, we've always used adult toothpaste for ours as advised by health visitors and dentists due to less fluoride being in the water these days. 1450 is the magic number I remember being told to look for in the ingredients to check if it had enough fluoride.

Applied topically.

Fluoride is great for teeth, but excesses are not great for the development of teeth.

Excess fluoride causes fluorosis which is hypo mineralisation of the enamel. Which can be unsightly and leads to issues with decay and pitting.

When I say excess, I mean ingested.

There are some toothpastes, like the whitening ones, that aren't recommended for younger children but most generic adult toothpastes are fine for kids. I've been using bog standard colgate on my 2 since they were toddlers.