Are my toddler's teeth rotting or just stained?

You have noticed something dark on your toddler's teeth, you have looked it up, and the internet has shown you photographs of rotted baby teeth.

Several harmless things look alarming at that age, and the one thing that genuinely matters does not look like what people expect. Knowing what each pattern means is usually enough to settle it before the appointment.

Decay starts chalky white, not brown

Early decay in a toddler shows up as a dull white band along the gum line, usually on the upper front teeth, and it looks like a faint chalk mark rather than a hole. Brown comes later, after the surface has broken down.

That white band is the stage worth catching, because it can still be arrested. Parents almost never worry about it, which is the whole problem with it.

Brown that appears without a white stage beforehand is far more often a stain than decay. The order tells you more than the colour does.

• dull white band at the gum line: early decay, act now
• brown or black that wipes along the surface: usually stain
• a soft spot or a hole you can feel: decay, dentist this week
• one grey tooth after a fall: trauma, dentist soon

Black lines along the gum are bacteria and they are harmless

A thin dark line following the gum line on several teeth at once is usually black stain, produced by a particular group of bacteria that live quite happily in some mouths. It is cosmetic.

Children with it tend to have fewer cavities rather than more, which surprises everybody. The bacteria involved are not the ones that cause decay.

A dentist polishes it off in minutes. It commonly comes back, which is irritating and still not a health problem.

I used to be an avid brown soda drinker and that stained my teeth so bad! I’m using Colgate Optic White toothpaste and it doesn’t hurt my sensitive teeth and it seems to whiten them! Every time I go home my family comments on my teeth and they ask me what I use. I’m not sure how long it takes, but I think on the box it says whiter teeth in 2 weeks? 💕

— r/beauty

Iron drops stain, and that stain means nothing

Iron supplements and iron-fortified vitamin drops stain teeth black or very dark grey, and the stain appears quickly. A great many parents have arrived at a dentist convinced the teeth were rotting.

Giving the drops with a syringe toward the back of the cheek, or through a straw for older toddlers, keeps most of it off the teeth. Brushing afterwards handles the rest.

The same goes for some medicines, and for strongly coloured drinks. Rinsing with water after anything dark is the whole technique.

I accept the stains. I am one with the coffee. Oddly enough though, I have bad teeth (working on fixing them is expensive and a pain in the ass), but they're not stained badly, despite it all. I do always follow up with water.

— r/beauty

Rough yellow-brown patches are something different again

Patches that are yellow or brown, rough to the touch, and sharply bordered are usually a defect in how the enamel formed rather than decay sitting on top of it. The term for it is hypomineralisation.

Those teeth are softer than normal and both decay more easily and feel sensitive, so they get watched closely and often sealed. The cause is formation during early childhood rather than anything a parent did.

A single tooth that has gone grey after a knock is a different story again, and it is worth showing to a dentist even if the child is untroubled by it.

What you can check at home, and what you cannot

Run a clean fingernail gently across the mark. Surface stain feels smooth and continuous with the rest of the tooth; early decay often feels slightly rough or chalky, and advanced decay catches.

Look at where it sits. Stain follows the gum line across several teeth evenly; decay concentrates on individual teeth and on the surfaces that touch each other.

Neither test settles it. Decay between two touching teeth is invisible from the front, which is why a dentist looks with a light and sometimes an X-ray.

They literally dont have the dexterity to get them clean till 8 that's why they dentist reccomends that. So yes I am brushing my toddlers teeth lol.

— r/toddlers

The brushing that prevents all of this is a two-person job

Children lack the hand control to clean their own teeth properly until around the age of eight, which is why dentists keep telling parents to do it for them long after it feels necessary. Letting a child brush first and then going over it yourself is the standard arrangement.

The upper front teeth and the gum line are the places to concentrate on, since that is where early decay appears. Lift the lip and look once a week.

Taking turns works better than negotiating. A child who gets to brush an adult's teeth first will usually sit still for their own.

My husband saw a tip online that said let the toddler brush YOUR teeth and take turns. This was an instant game changer for us.

— r/toddlers

Common questions

How do I know if my toddler's teeth are decaying or stained?

Decay usually begins as a dull chalky white band at the gum line and turns brown later. Stain is smooth, follows the gum line evenly across several teeth, and does not catch a fingernail. Only a dentist can see between touching teeth.

Why does my toddler have black lines on their teeth?

Most likely black stain produced by a harmless group of bacteria. Children who have it tend to get fewer cavities, not more. A dentist polishes it off quickly, though it often returns.

Do iron drops stain baby teeth?

Yes, often black or dark grey, and it appears fast. Giving the drops toward the back of the cheek with a syringe, or through a straw, keeps most of it off the teeth, and brushing afterwards removes the rest.

What are the white marks on my toddler's front teeth?

A dull white band at the gum line is early decay, and it is the stage at which it can still be arrested. It should be seen soon rather than watched, because the next stage is a hole.

At what age can a child brush their own teeth?

They can hold a brush much earlier, but they lack the dexterity to clean properly until around eight. Let them brush first and then go over it yourself, concentrating on the gum line of the upper front teeth.

Lift the lip and look along the gum line of the upper front teeth in good light. A dull white band there is the one finding worth acting on quickly, and it is the one almost nobody photographs.

If what you can see is smooth, even, and spread across several teeth, it is almost certainly stain. Book the routine appointment rather than an urgent one and ask them to look while you are there.