White spots on your teeth aren't necessarily a problem. Some people might have had these spots for years while knowing exactly what causes them. But if white spots should rapidly begin to form on your teeth without any clear cause, you'll need to see your dentist.

Lasting White Spots   

Lasting white spots can be due to natural irregularities in a person's dental enamel. They can also be caused by fluorosis, which is when someone consumed excessive amounts of fluoride during childhood when their enamel was forming. Treatment isn't always needed, although dentists keep a close eye on teeth with irregular formations or fluorosis, allowing them to restore the tooth if it ever becomes relevant.

New White Spots 

White spots that have quickly developed on an adult's teeth are generally another matter. While you might wonder if the issue is caused by fluorosis or an irregularity with your enamel, this isn't likely. These conditions are either lifelong or were acquired in childhood, and so won't spontaneously develop in adult teeth. It's more likely that the mineral composition of your dental enamel is changing—and changing for the worse.

Mineral Loss

Mineral loss in dental enamel is a precursor to a cavity. These white spots are breaches in your dental enamel. Without quick treatment, further decay is difficult to avoid. Should your enamel corrosion continue, a cavity will form. But since these white spots are essentially tiny holes, shouldn't you just have them patched with tiny fillings?

Enamel Repair

Your dental enamel can't regrow itself. When it's gone, it's never coming back. Your form of mineral loss is not (yet) advanced, so you may not need a filling. Instead, your dentist will perform a treatment that can remineralise your enamel, leaving deposits of restorative minerals that will fill these tiny breaches in the surfaces of your teeth. 

Remineralisation

Dentists remineralise teeth using a fluoride treatment. You've probably had one of these treatments before, as they're common during regular checkups. Fluoride is applied to teeth, allowing the necessary time to set, before you rinse and spit. Depending on your level of demineralisation, several sessions might be needed. This treatment will not trigger fluorosis, as your dental enamel is already fully-formed.

Once your teeth have been remineralised, you should ask your dentist how to avoid repeating the problem. You may need to step up your oral hygiene game, and your dentist might recommend a specific toothpaste to continue your remineralisation efforts at home.

Consult with your dentist to make sure your teeth are in good condition.