Dental cavity (caries) is as the name implies, a hole in the tooth caused by dental decay. The root cause of dental decay is our old friend plaque. Let plaque get out of control by not brushing / flossing adequately or visiting your dentist for your dental cleaning and you risk tooth decay, one or more cavities may form.

How exactly do cavities form?
As we detailed about plaque, the bacteria produces acids which are prevented from being neutralised by the layer of bacteria themselves. The acid errodes the enamel causing the cavity. The cavity can form so deep it reaches the tooth nerve becoming very painful.

How do I know I have a cavity?
Until the cavity hits the nerve there aren't really any symptoms apart from some sensitivity. Once the cavity hits the nerve it can become very painful. Your dentist can spot cavities before they have reached the nerve during a routine checkup.

What's the treatment?
If you or your dentist detect a cavity your dentist will have to drill out any rot and fill the remaing hole with a filler material, which used to be gold and silver but these days tend to be porcelain or resin. If tooth damage is too extensive for a filling a crown or cap. If the tooth is so far damaged the nerve may have also died thus needing a root canal before the crown or cap is in place.