I noticed last night my bottom teeth had a little bit of white instead of pink gum around it. what could it be from?

Dental cleaning: If the gums are white, then it could be dead tissue sloughing off. It's not uncommon, and you should not be too concerned if it disappears. If it's a hard build-up on your teeth, then it is saliva deposits and bacteria that need to be removed with instruments - i.e. A dental cleaning. This also is common in lower teeth, but you can minimize it by flossing.