Dental Cavities: How They Form, Their Stages and How to Treat Them Early

What a cavity actually is

A cavity is the gradual breakdown of a tooth caused by acids that the bacteria in your mouth produce. It isn't a hole that appears out of nowhere: it's a slow process that begins long before you notice anything unusual or feel any pain.

The encouraging part is that in its earliest stage a cavity can be halted, and even reversed, without a filling. That's exactly why understanding how decay works is the best tool you have to look after your teeth.

How it forms: plaque, sugar and acid

It all starts with dental plaque, the sticky film that builds up on your teeth throughout the day. Inside that plaque live bacteria that feed on the sugars and starches we eat.

The sequence is easy to picture:

• You eat or drink something containing sugar.
• The bacteria turn it into acids.
• Those acids attack the enamel and steal its minerals (calcium and phosphate). We call this demineralisation.
• Helped by saliva and fluoride, the tooth tries to put those minerals back (remineralisation).

As long as the balance holds, no cavity forms. Trouble begins when the tooth loses minerals faster than it can replace them, which is common when we snack on sugar often or let our hygiene slip.

The stages: from white spot to deep decay

Decay advances layer by layer, and the treatment is different at each point:

• White spot. The first warning sign: a chalky, opaque patch on the enamel. There's no hole yet, and with fluoride and good hygiene it can be stopped.
• Enamel cavity. The surface starts to break down and a small cavity forms. It's usually painless, which is why it slips by unnoticed.
• Dentine cavity. Beneath the enamel lies the softer dentine. Here decay moves faster and you may feel sensitivity to cold or sweets, or discomfort when chewing.
• Nerve (pulp) involvement. If it reaches the inside of the tooth, sharp pain appears and infection can set in. This is the most complex stage to treat.

The whole point is catching it early, while it still doesn't hurt.

How to prevent cavities day to day

Prevention isn't complicated, but it does need to be consistent. Here are the essentials:

• Brush twice a day for two minutes with a fluoride toothpaste. Fluoride helps make enamel more resistant to acid.
• Floss or use interdental brushes once a day: your brush can't reach the gaps between teeth, and that's where many cavities begin.
• Watch how often you eat sugar, not just how much. Frequent sweets or soft drinks keep the acid attack going all day. It's better to keep sugar to mealtimes.
• Drink water, and wait a while before brushing after something very acidic.
• Regular check-ups. A visit lets your dentist spot early decay you can't feel, and a professional clean removes hardened plaque.

How each stage is treated

Treatment depends on how far the cavity has progressed:

• White spot: professionally applied fluoride, better hygiene and sometimes sealants. The aim is to remineralise without touching the tooth.
• Enamel and dentine: the classic filling. The damaged area is cleaned out and rebuilt with a tooth-coloured composite.
• Close to the nerve: a root canal may be needed to remove the affected pulp and seal the canal. With local anaesthetic you won't feel pain during the procedure.
• Badly damaged tooth: it may be reinforced with a crown or, if it can't be saved, extraction and replacement are considered.

Every mouth is different, so this article is informational and doesn't replace a personalised clinical assessment.

Take the first step at Debod

At our clinic in the Argüelles neighbourhood we believe in honest dentistry: catching problems early usually means simpler, more conservative treatment. If it's been a while since your last check-up, or you've noticed any discomfort, we'd be glad to see you for a first diagnostic visit included. You'll find us at C. de Ferraz, 24, Madrid (Ventura Rodríguez metro, L3). Call us on +34 914 47 62 25 or message us on WhatsApp at +34 689 10 47 14.