Fine black dots or a dark line along the gum line in children are usually so-called black stain, a harmless discolouration on the tooth surface. Around one in ten children has it. Certain bacteria in plaque and iron-containing compounds that stain black are probably involved. Brushing at home hardly removes the discolouration, but a professional clean does. Black stain is not a sign of poor care, and according to studies, children with these stains tend to have less decay. Have dark spots checked all the same: a dark spot in a groove or a soft area can also be decay.
Updated: 9 November 2026
Black stain or decay?
| Black stain | Decay | |
|---|---|---|
| Appearance | fine black dots or a line close to the gum, often on several teeth | brown to black spot, often in pits, grooves or between the teeth |
| Surface | smooth and hard | rough, soft or already a hole |
| Symptoms | none | later a twinge with sweet or cold food |
| What helps | a professional clean | treatment at the practice, the earlier, the gentler |
Where the discolouration comes from
This is not yet fully understood. The plaque of these children contains particularly many of certain bacteria and iron-containing compounds that stain black. Iron-containing juices or drops can also stain teeth dark. Why children with black stain tend to have less decay is something researchers do not yet know.
What helps
- At home: thorough brushing prevents new plaque, but it hardly removes the existing stain. Scratching or rubbing with home remedies such as baking soda or lemon is more likely to harm the enamel.
- At the practice: at a children’s dental hygiene appointment we gently remove the discolouration with a warm powder-and-water jet and polish the teeth.
- Afterwards: in many children, the discolouration comes back after a few months. Then we clean again, usually as part of regular dental hygiene.
Children’s dental hygiene with us
For children from six to 16, dental hygiene is shorter, more playful and without pressure. We colour the plaque so the children can see where it sits, and practise how to remove it themselves. The cleaning is the same as for adults, with the GBT system and a warm powder-and-water jet, only shorter.
