somertimeoh wrote >>
Ohmigawsh, I thought Pepsi was already super sweet!! How does this affect your tooth enamel? Is real sugar less, equally, or more damaging than HFCS?
Tooth decay is (as far as I know) caused by bacteria eating the fructose/sucrose/others(?) and excreting lactic acid. So basically it's fermentation in your mouth. Since HFCS contains fructose and sugar contains sucrose, the question becomes either "which one do bacteria prefer" or "how much of each is going into each can of soda."
I can't find anything about the comparative speed of metabolism for fructose vs. sucrose by this bacteria, but honestly, my guess is that if you're brushing twice a day the difference in acid buildup won't be appreciable.
So the amount, then. I can't find anything on the amount of sugar in pepsi throwback, maybe because it's too new for dieting sites/middle school science classes to have posted their results online. Since they taste about as sweet, and looking at fig. a, I'm guessing more raw sugar goes into Pepsi Throwback than HFCS micture, but there's about the same amount of -crose in there either way.

fig. a
In conclusion: I dunno, it's probably about the same. Someone tell me if I'm wrong!