Since fluoride is really only taken to protect the teeth, it's your dentist who is going to see when extra fluoride is needed. They are also in the perfect position to monitor your situation and adjust it accordingly, that is assuming you go to see a dentist.
The more high risk you are for dental caries, the more benefit you will get from having regular fluoride treatments at your dentist. For those of you who are low risk and can’t remember the last time you had a filling, using a fluoride toothpaste is generally all you need.
Brushing your teeth; simply spitting out the toothpaste and NOT rinsing- last thing before you go to bed- is like giving yourself a mini fluoride treatment. In fact, every time you brush, that is exactly what you are doing.
If you are high caries risk (whatever your age) then extra fluoride is crucial to help protect your teeth and prevent cavities. Caries risk takes into account many different factors. Here are a few related questions which if you answer 'yes' to, then these are signs extra fluoride may be needed:
(i) Are you wearing orthodontic braces?
(ii) Are you wearing a partial denture?
(iii) Do you suffer dry mouth or xerostomia?
(iv) Have you had radiation to the head and neck?
(v) Do you always need lots of dental treatment?
(vi) Do you have new cavities every time you go to the dentist?
(vii) Has your dentist told you that you have early dental caries in your mouth? (enamel caries on bite wing X-rays
(viii) Do you have lots of recession and root surfaces exposed?