There are no 100% SCD legal toothpastes. But, Elaine said that if your child will spit out the toothpaste and not swallow - to not worry about commercial toothpaste (but use only a small pea-sized amount).
Here is a SCD legal toothpaste recipe that was posted a couple of years back (from Juliette):
6 tsp. baking soda
1/3 tsp. salt
4 tsp. glycerin
12-13 drops peppermint of wintergreen extract
Just mix and store at room temperature.