my sam had something black/grey on his tooth

when i was trying to get it off somehow it went up in gum should i worry or will it be fine?

I would think it would come dislodged from him chewing and either be swallowed or spat out.

I doubt that it went right into his gum, it would have made it bleed & you'd have seen it. Does he seem in any discomfort?

i saw it go up i was trying to get it off and it just slip up in his gum...

I'd keep an eye on it. If the gum starts to look a bit red, or if he starts to try & scratch it, you'd best let the vet take a look. It might come out on its own.

i will do it wasn't something big pretty small really i don't have a clue what it was

Odd.

Goodness knows what dogs pick up in the garden. Could be a bit of leaf or a flower petal.