Approximal decay develops on the surfaces where neighbouring teeth face one another. It is common, often difficult to notice and may require substantial treatment. Here is why it develops, how to reduce the risk and what makes treatment challenging.
Why does decay develop between teeth?
The spaces between teeth are harder to clean, allowing plaque to accumulate. Bacteria in plaque produce acids from sugars, gradually weakening enamel. Contributing factors include:
- Inadequate cleaning: Without floss or an appropriately sized interdental brush, plaque can remain between teeth.
- Tight contact points: Close contacts can make cleaning more difficult.
- Sugary or acidic food and drinks: Frequent sugar exposure feeds acid-producing bacteria. Acidic products can also contribute to erosion.
- Fillings and restorations: Poorly fitting edges may trap plaque and make cleaning difficult.
How might you notice it?
Decay between teeth can occur at different ages, including in people who brush well but do not clean between their teeth. It often remains hidden until it has progressed.
Possible early complaints include:
- Vague or intermittent sensitivity around the affected teeth.
- Dental floss catching or fraying.
- Food repeatedly getting trapped between teeth.
How can you reduce the risk?
- Regular flossing: Floss can clean tight contacts where an interdental brush will not fit.
- Interdental brushes: Use the correct size where there is enough space; do not force one through a tight contact.
- Fluoride toothpaste and appropriate mouthwash: Fluoride helps strengthen enamel. Mouthwash is an additional measure when advised, not a substitute for brushing and interdental cleaning .
- Regular dental check-ups : Hidden decay may be detected with an examination and appropriately indicated bitewing X-rays.
- Limit frequent sugar and drink water: Reducing sugary snacks and drinks helps lower decay risk.
Why can treatment be difficult?
The narrow space and limited access between teeth require precise work. At our clinic, we take a careful approach to these challenging restorations.
- Precision: The dentist aims to remove diseased tissue while preserving as much healthy tooth as possible.
- Visibility and access: Mirrors, suitable lighting and imaging help the dentist assess and restore difficult-to-reach areas.
- Appearance: The restoration should blend with the tooth, particularly in the visible front region.
Why can a small hole require a larger restoration?
A small surface opening can conceal more extensive damage beneath the enamel:
- Dentine below the enamel is less mineralised, so decay can spread more widely beneath a relatively small surface defect. The external appearance can underestimate the damage.
- Treatment must address the lesion and create a sound seal. In deep cavities, the approach is tailored to protect the pulp where possible.
- Access and unsupported enamel may mean the final restoration is larger than the visible opening suggested.
Summary
Decay between teeth can remain unnoticed and cause substantial damage if left untreated. Effective interdental cleaning and timely dental assessment are central to prevention and treatment. Restoring the tooth requires care to preserve healthy tissue and rebuild a functional contact.
Regular reviews, suitable interdental cleaning and consistent daily care can make a real difference.
For details of the relevant treatment, see our page on professional tartar removal .
For more practical detail on this topic, see a comparison of dental filling materials .