What are these white spots on my teeth?!

We’re all in pursuit of pearly whites—but what if you wake up one day and realize that your teeth suddenly have white...spots? Yep, we’re talking about those irregular milky opaque patches that disrupt an otherwise evenly-hued set of chompers. Not only are they aesthetically troublesome, they could be cause for concern.

But before you hit speed dial on your dentist, let’s look at what causes these white spots to appear, when you should seek professional help, and what can be done to prevent them in the first place.

IF YOU'VE HAD WHITE SPOTS FOR FOREVER...

If these spots have been present since childhood, it’s likely they’re due to fluorosis, an excess of mineralization caused from drinking water with high fluoride levels as a child. This is seen more in adults who grew up with well water or, as children, consumed water that had more than two milligrams of fluoride per liter, according to the Centers for Disease Control and Prevention.

Fluorosis happens before your permanent teeth come in, explains Ram Vaderhobli, a dentist and associate professor of preventive and restorative dental sciences at the University of California, San Francisco School of Dentistry. Meaning, if you’ve lost all your baby teeth and are drinking water with a higher concentration of fluoride, it won’t cause fluorosis.

Since fluorosis is caused by an excess of fluoride exposure, the white spots actually represent the strongest parts of the tooth—but that scenario gets totally flipped if your white spots show up all of a sudden.

If they're new to the party...

If you’re an adult just noticing white spots now, it’s likely they’re a sign of plaque buildup known as decalcification, says Lisa Simon, a dentist at Harvard School of Dental Medicine.

“White spots can be the first way a cavity appears,” Simon says. “It could be where the tooth is weaker, so you might see them toward the bottom of your tooth where your gums are, or notice them with new sensitivity when drinking sugary beverages.”

On a more technical level, these white spot lesions are color irregularities caused by enamel demineralization—meaning, when the tooth has been exposed to plaque or sugar, the mineral content that keeps your teeth strong changes.

These types of white spots can also show up after the removal of braces in places where a toothbrush couldn’t reach and plaque accumulated. Alternately, Simon notes, it could possibly be a tooth-colored filling that’s become more noticeable because you’ve accumulated teeth stains or recently whitened.

Wait, could this be whitening gone wrong?

One assumption is that tooth whitening could cause these spots to show up, but Simon says that’s not necessarily true.

“The way [whitening products work] is that if you put it on one part of your tooth, it then enters tubules through the tooth and distributes itself,” she explains, noting the delivery is the same via both drugstore white strips and professional whitening products and procedures. Thus, a patchy result is unlikely.

Whitening processes, professional and at-home, are designed to “blend the changes in the opacity,” says Vaderhobli. Additionally, bleaching is sometimes recommended as a solution to fade white spots, blending the lesions to match the surrounding shade.

When should I see a doctor?

Rest assured, says Simon, as your dentist is checking for white-spot warning signs every time you head in for an appointment. However, if you’re experiencing pain or increased sensitivity it could be time to consult an expert.

“An x-ray or touching the spot with a dental instrument would determine if the spot is decalcification,” she continues. And don’t worry, they’re checking your back molars for loss of tooth strength and structure—and yes, spots. “It’s not a cavity at that point, so the goal is to identify them before you have to get a filling. If it ends up bigger or pitted and you’re noticing increased sensitivity, those are signs the cavity is now growing.”

If you’re still not sure whether the spots are fluorosis or decalcification, Simon recommends checking if the lesions appear at the same height across multiple teeth. If they do, and they appear toward the base of the teeth, it’s like they’ve actually been there all along. “They’re signs nothing needs to happen.”

So what should I do?

Good news: If you're not in pain, you probably don't need a trip to the dentist's chair. The spots can sometimes be brushed away through regular maintenance and cutting back on the sugar, Simon says. “They can be reversed,” she says. “Brush well, stop with the sugar, use fluoride, and they should go away in around a month or so.”

In more extreme cases, Vaderhobli says a newer restorative technique called resin infiltration, which is currently being studied as a no-drill cavity fix at the University of Alabama at Birmingham, is an in-office, lower cost option to remove the spots completely. Vaderhobli says the cost for the procedure varies between $140 to 150 per tooth, and insurance could even cover it. The tooth’s surface is roughened with a diluted hydrochloric or phosphoric acid mixture, the white spot is etched and dried, and then smoothed over with white filling material, which absorbs into the spot.

Of course, Vaderhobli says this is typically worst-case scenario. “We always recommend minimal intervention.”

Brush twice a day for two minutes, echoes Simon. “All toothpastes on the market have the same amount of fluoride in them, either in sodium fluoride or stannous fluoride. So people can just pick their favorite flavor or brand,” she adds. “A dentist can prescribe higher fluoride toothpaste for people with a very high risk of decay as well.”

And for bonus points, “avoid rinsing, eating, and drinking after brushing [your] teeth to help keep the fluoride present for longer.”