What does the process of "remineralization" of tooth enamel consist of?

Rebuilding: Demineralization is when a tooth has lost its minerals (calcium, phosphorus) and is weakened. Remineralization is when it gains it back and is restrengthened. The enamel can also trade a Fluoride atom for an oh- molecule and become even stronger than it was before. Thats why they put Fluoride in the water and in toothpaste -- sometimes a dentist may also refer to this as remineralization.

Saliva is Good!: Tooth enamel is constantly being depleted by minerals when you eat acid, and minerals are constantly being deposited by saliva. When a tooth has a weak spot, adding more minerals and creating less acid will slant the process towards more minerals into the enamel; thus 'remineralization' it takes a special kind of calcium plus, usually, Fluoride to make this happen. Ask your dentist.