I will not regularly use anything containing fluoride because it is possible that the fluoride is toxic to at least part of the population though I might have fluoride applied to a part of a tooth that a dentist has identified as being decalcified.

My body is less able to remove or render inactive a wide variety of toxic chemicals, which is a common condition. It is hard for me to know what someone without that condition should do about fluoride, but it is far from clear that the right decision is to use fluoride unless one is particularly prone to cavities. (I suspect that most fillings placed in adults in the U.S. are unnecessary and would not be recommended if the dentist did not want to increase his or her income, so if a dentist you do not know well recommends a filling, get a second opinion.)

P.S. Most of the time when I brush, I use a drop of mild liquid soap (Method dish soap or Dr Bronner's). Sometimes I use hydrogen peroxide (when I think it might help to kill the kind of bugs in my mouth that peroxide will tend to kill). And very occasionally when a patch of my gums experience a certain kind of itchiness that I associate with bad bugs, I will use a mouthwash containing chlorhexidine. I have not bought toothpaste in about 10 years because except for the fluoride I have seen no evidence that they're better than the alternatives listed above. E.g., all of the toothpaste I have looked at contains soap or detergent, typically sodium laureth sulfate. They've all also contained some sort of fine particles of some calcium-containing substance, but I assign no expected utility to that.

EDIT: removed text implying that neurotoxicity is the most problematic adverse effect of fluoride. (It's been so long since I looked at fluoride, I forget what effects worried me.)