Dextrose is fine.
This is my breif view when Comparing "Refined White Sugar" And "Artifical Sweetners" like the one you mentioned Aspartame: Refined white sugar and artificial sweetners involve what I call: "a bad choice set", and one has to look at the pros and cons of this bad choice set, and make a decision among a potentially bad choices. Most persons on the forum know that Refined White Sugar is no good, and you will get various opinions on artificial sweetners, but I personally chose Splenda as my alternative to Refined white sugar.
Alot of the nonfat and low calorie Yogurts have Aspartame in it, and some are coming around to Splenda as well. I have consumed Aspartame to no known ill effects--at all. Personally, I would take an alternative to refined white sugar any day (after educating myself on the alternative choice of course). In the diet sense (only), I would recommend staying away from refined white sugar like it has AIDS, and go to a artificial sweetner your comfortable with consuming (and not everyone is in the same opinion on artificial sweetners), but I believe eliminating white sugar in a diet is beneficial and artificial sweetners do not harm a person wanting to lose tissue weight (when weighing these two choices).