Bono's teeth

Okay, maybe I am stooping to a new low on Wire by bringing this subject up,
but it seems that between the Unforgettable Fire era and the time of
JT/R&H, Bono did something to his teeth, like get caps or something. Do
they look different to anyone else? He had something done to at least the
top row. I'm sorry if this seems unnecessarily trivial to some of you, but
I have really been wondering! Answer me if you know! Thanks......