Dental decay happens when the enamel and dentine of a tooth become softened by acid attack, producing a cavity (hole). Dental decay is caused by plaque acids that gradually dissolve away the enamel and dentine of the tooth to produce a cavity. Dental decay is the same as tooth decay and is also known as ‘dental caries’. Decay damages your teeth and may lead to the tooth needing to be filled or even extracted.
Decay happens when sugars in food and drinks react with the bacteria in plaque, forming acids. Every time you eat or drink anything containing sugars, the bacteria reacts with it to form acid. These acids attack the teeth and start to dissolve the enamel. The attacks can last for an hour after eating or drinking, before the natural salts in your saliva cause the enamel to ‘remineralise’ and harden again. It’s not just sugars that are harmful: other types of carbohydrate foods and drinks react with plaque and form acid. (These are the ‘fermentable’ carbohydrates such as the ‘hidden sugars’ that can be added to processed food, natural sugars like those found in fruit, and cooked starches.) Snacking on sugary or acidic foods and drinks can increase the risk of decay, as the teeth come under constant attack and do not have time to recover. It is therefore important not to keep snacking on sugary foods or sipping sugary drinks throughout the day.
In the early stages of dental decay there are no symptoms, but your dentist may be able to spot an early cavity when they examine or x-ray your teeth. This is why you should visit your dentist regularly, as small cavities are much easier to treat than advanced decay.
Once the cavity has reached the dentine your tooth may become sensitive, particularly with sweet foods and drinks, and acidic or hot foods. As the decay gets near the dental pulp you may suffer from toothache. If the toothache is brought on by hot or sweet foods this may last for only a few seconds. As the decay gets closer to the dental pulp the pain may last longer and you may need to take painkillers – paracetamol or ibuprofen – to control the pain. You must visit your dentist immediately as the tooth is dying and you may develop a dental abscess if it is not treated.
Toothache is a sign that you should visit a dentist immediately, as it is a warning that something is wrong. If you don’t do anything, this will usually make matters worse, and you may lose a tooth that could otherwise have been saved. If the decay is not too serious, the dentist will remove all the decay and restore the tooth with a filling. Sometimes the nerve in the middle of the tooth can be damaged. If so the dentist will need to carry out root canal treatment by removing the nerve and then restoring the tooth with a filling or a crown. If the tooth is so badly decayed that it cannot be restored, the only option may be to extract the tooth.