When you have tooth decay and a cavity, what has happened is that bacteria have infected your tooth and eaten it away with acid. In the early stages, this does not cause pain but can be found during your regular check-ups by your dentist. When the bacteria eat away the tooth closer to the nerve under your enamel, you might get sensitivity to eating and drinking cold, sweet and hot things. During the early stages we may try to re-harden your enamel by remineralizing it with fluoride and calcium. But once the bacteria have infected the tooth past your enamel, they need to be removed.
To remove bacteria that has infected deep into your tooth, we must amputate part of your tooth that has been infected and has rotted away (decay). We do this under anaesthetic, so you don’t feel pain. Once the bacteria have been removed, your tooth is left with a hole in it that is bacteria free. However, if we left your tooth at this stage with no protection, the nerves would be exposed and you would have sensitivity, food will get stuck in it and your tooth has no defence against new bacteria coming to infect it. Thus, we need to fill your tooth with a restoration, commonly known as a filling.
Fillings can be thought of like a prosthetic leg if you had your leg amputated. It will enable you to chew on your tooth again without sensitivity and food getting stuck in it. It acts like a man-made enamel to protect your tooth against bacteria. If you can treat cavities and decay when they are small, fillings can restore your tooth’s form and function for many years and avoids the need for root canal treatment or crowns.
Restoring form and function of your tooth after damage by bacteria is the main reason you may need a filling. Other reasons may include: cracked or broken teeth or old fillings needing replacement as they have worn down with use – sort of like your car that needs regular servicing. So, to keep your fillings small and lasting longer, make sure you get your regular check-ups to prevent bigger problems and extend the life of your existing fillings.