If you use a 100v ac drill on 110v ac allthough it might invalidate the warranty and outside manufacturers spec it'll still probably be fine with a 10% difference, particularly with speed control as you can just wind it down a little.
The part that would be subject to extra stress would be the speed control and emi suppression side, which probably has a sensible amount of headroom anyway.
Is the drill a brushed universal motor?
Edit: I just checked my dremel (its is a dremel) its 125w, I use mine for engraving and occaisonally for cleaning and polishing hydraulic valves, for this purpose its just about powerfull enough, the one you linked us too is only 50w, thats not a lot, depending what you want to do with it you might want to consider something beefier.