lots of juices don't have aspartame in them, you just have to read the labels and everything is bad for your teeth even fruit so regular brushing with floride free toothpaste is best.
here a list with the most popular aspartame products:
Diet Coca Cola (all varieties)
Coca Cola Zero (all varieties)
Diet Pepsi (all varieties)
Pepsi Max (all varieties)
Diet Irn Bru (all varieties)
Lilt Zero (all varieties)
Sprite Zero (all varieties)
Tango (all varieties)
Tango no added sugar (all varieties)
7up Free (all varieties)
Lucozade Sport (all varieties)
Schweppes Slimline Drinks (all varieties)
Fanta Zero (all varieties)
Fanta Orange
Dr Pepper Zero
Oasis Summer Fruits Extra Light
Oasis Citrus Punch
Ribena Really light (all varieties)
Robinsons Orange Squash
Robinson’s No added sugar range
Muller Light Cherry
Muller Light Blueberry
Muller Light Raspberry
Muller Light Banana and Custard
Danone Activia Cherry
Weight Watchers Fromage Frais
Weight Watchers Toffee and Vanilla
Wrigleys Airwaves (all varieties)
Wrigleys Orbit (all varieties)
Wrigleys Extra (all varieties)
Uncle Ben’s Sweet and Sour Light Cooking Sauce
Walkers Sensations Sweet Thai Chilli
Walkers Sensations Lime and Thai Spices
Walkers Prawn Cocktail
Canderel
Silver Spoon Sweetness and Light
Silver Spoon Light Granulated Sugar
Cadburys Highlights (all varieties)
Options Hot Chocolate Drink (all varieties)
Hope this helps!