If acids cause the -OH group in hydroxyapatite to break off, and fluoride remineralizes it and makes it more acid resistant by replacing the -OH with a -F, then do dentists ever apply acids (having someone gargle and rinse with something with a low pH like listerine as an example) to weaken the enamel before applying a fluoride paste to speed up the process of mineralization and replacing the -OH with -F?
Or would that cause fluoridosis, or some other condition, or just not be necessary? Does enamel absorb fluoride anyway irrelevant of pH?
If listerine has a pH of about 4, does using listerine before you brush harm your teeth, help your teeth or not make a difference in the process of demineralization and remineralization?