You have small wedge-shaped notches at the gum line of your teeth. They're not cavities — they're abfractions. Here's what causes them and whether they need treatment.

Abfractions are those curious, V-shaped or wedge-shaped indentations that appear where the tooth meets the gum. They're slightly below the gum line, often on the cheek side of the teeth. They're not decay, and they're not caused by brushing too hard, despite what many people believe.

Abfractions are caused by flexural stress on the tooth. Think of a tooth as a beam. When you bite down, the tooth bends slightly — even if it's microscopic, it happens. Over time, this repeated bending causes the enamel and dentine to weaken and fracture away at the neck of the tooth, right where the load is greatest.

The biomechanical load comes from your bite. If certain teeth carry too much force — because of clenching, grinding, or an uneven bite — they're under more stress. That's where abfractions tend to form.

Your gum tissue also recedes slightly as you age, which can expose these lesions and make them more visible.

No. A cavity is caused by acid-producing bacteria that dissolve your tooth structure. An abfraction is a mechanical fracture — the tooth structure actually breaks away due to stress. They look similar in some ways, but the cause and the treatment approach are different.

That said, abfractions can sometimes trap food and bacteria, which may lead to decay in the lesion itself. So even though the abfraction isn't a cavity, it can create conditions where cavities form more easily.

It depends on the severity and whether they're causing symptoms. Small, shallow abfractions that aren't sensitive often just need monitoring. Your dentist will check them at your regular appointments to make sure they're not getting worse.

If the abfraction is deep, sensitive, or progressing, treatment can help. Bonding with a tooth-coloured resin can fill the notch and protect the exposed tooth structure. This also reduces sensitivity and improves appearance. In some cases, a crown is recommended to fully cover and protect the tooth.

Addressing the underlying cause — such as adjusting your bite or using a bite guard — is important too. Without that, new abfractions can form on other teeth.

If you clench or grind your teeth, mention it to your dentist. A custom bite guard can reduce the stress on your teeth and slow down further abfraction formation. Good oral hygiene also helps — keeping the area clean reduces the risk of decay developing in the lesion.