Answer: Very simply because most toothpastes have "breath freshening" agents which tend to stick to your teeth and gums, and the cold and acidity of the orange juice reacts with menthol that tends to be in these breath freshening agents.
Answer: Orange juice naturally contains a lot of citric acid. If you ingest too much in a short amount of time, the rapid influx of citric can imbalance the hydrocholoric acid produced by your stomach and you may throw up. trhbfvZXsazx
Answer: No, orange juice has no changing effect. Try a vitiman supplement called DLPA, which can be found in healthstores. You can even purchase them online. Amazon.com has everything you need as far as that goes.