You look in the mirror and notice something strange. The main body of your tooth looks fine — white or off-white — but right at the gum line, your teeth are yellow or brown. It does not brush away. What is going on?
Why Is the Gum Line a Different Colour?
The enamel at the neck of your tooth is thinner than elsewhere. This part of your tooth sits right next to your gums and is more vulnerable.
As enamel thins with age or brushing pressure, the darker dentine underneath shows through. This is the most common reason for yellow or brown discolouration at the gum line.
It is not usually just staining from coffee or tea. The pattern matters — a distinct band at the gum line has specific causes worth understanding.
What Causes Yellow or Brown Staining at the Gum Line?
Tooth wear is a major factor. Over-brushing, acidic erosion, or simply the passage of time thins the enamel at the cervical margin. Once dentine is exposed, the tooth appears darker right where the gum meets the tooth.
Calculus build-up is another culprit. Tartar often forms just below the gum line and ranges in colour from yellow to brown. Unlike surface stains, calculus requires professional removal — brushing cannot shift it.
Some people have naturally thinner enamel in this area due to their genetics or during tooth development.
Is It Decay or Just Staining?
It can be hard to tell at home. A brown spot at the gum line could be a cavity, particularly if the tooth feels soft or rough when you probe it with your tongue.
It could also be a filling that has started to fail, leaving a dark margin at the edge.
Only a dentist can reliably tell the difference. If you notice a new dark area, or one that seems to be getting worse, book an appointment.
What Can Be Done About It?
If the cause is calculus, a professional clean will remove it. Your dentist or hygienist uses ultrasonic instruments to clear tartar from below the gum line.
If the cause is enamel erosion and dentine exposure, options include bonding to cover the exposed area, a filling to restore the contour, or veneers for a more cosmetic result.
To prevent it getting worse, your dentist can advise on brushing technique — yes, you can brush too hard — and whether an acidic diet is contributing to the erosion.
Book a Check-Up
A dark line at your gum line is worth getting checked. Your dentist can identify the cause and recommend the right treatment before it progresses.
Call 01323 723757 or book at www.meadsdental.com
Meads Village Dental Practice