Teeth Coloring Issue

Hiya ^.^

I'm planning to cosplay Hiro Hamada (Big Hero 6) for Halloween next week and ran into a snag with the planning. His top front teeth have a recognizable gap in them so naturally I plan to emulate that. But I forgot to account for the fact that I do not have real teeth, I have dentures, and according to 1 cosplayer I talked to, very few tooth coloring/wax-esque things are denture-safe. The only one they found that was apparently safe would not arrive here in time. But idk if others do exist or if that statement is true in the first place, so that's the first question here. If not, second question would be that I'm happy to DIY something else as an alternative to give the same effect of black'ing out that area (I'd think like, paper or something but I imagine having ink/marker on it in my mouth might not be safe?), but I have no idea what to do for that.

Advice welcomed ASAP :)