Probably does both but only temporarily. I don't think that "it restores the anti-bacterial properties of saliva". Saliva has those properties, the problem is there isn't enough saliva to bathe the teeth. It does provide anti-bacterial agents but only topically and temporarily.

I use Biotene toothpaste after every meal. I use the mouth spray rarely, I used it more frequently immediately after treatment. The best thing is to have "Trays" made by your dentist for your teeth that you wear at night after spreading "Recaldent", a high fluoride paste, on your teeth.