When you notice a cavity on a tooth for the first time, you might feel that there's no hurry in having it repaired—after all, the damage has already been done. But the quicker you act, the less intensive any treatment must be. And if you know how to spot the very early warning signs of a cavity, you may not even need a filling to restore your tooth.
There's no definitive schedule, and it can take several months to several years for a cavity to form, which is a fairly broad timespan. Don't let this information lull you into a false sense of security. Just because it might take years for a cavity to properly form, it doesn't mean you can wait years to have a suspected cavity inspected by your dentist. Teeth restoration is more straightforward when performed as early as possible.
The speed of cavity development varies considerably. Your diet and level of oral hygiene are key factors, but regardless of the speed, the formation of a cavity follows the same process. Oral bacteria in your mouth interact with various compounds in your diet (primarily sugars and starches), and this interaction creates acid. The acid then begins to corrode the outermost layer of your teeth, which is made of dental enamel.
As your dental enamel begins to corrode, a small indentation (which is sometimes discolored) may be visible. This is when corrosion is still limited to the enamel and is known as a micro-cavity. These should be treated urgently. The corrosion process has demineralized your enamel, and can often be halted with manual remineralization. An intensive fluoride treatment performed by your dentist may be enough to stop further cavity development, meaning you won't need a filling.
If the corrosion actually breaches your enamel, it has reached the dentin beneath. Dentin forms the majority of a tooth's structure. Once dentin is exposed, you're more likely to feel a cavity, since the tooth can become noticeably more sensitive. You'll need a filling, which consists of removing the decayed portion of the tooth before the resulting hole is filled with a tooth-colored dental resin.
Your Dental Pulp
Should treatment be delayed, your cavity can deepen even further. If it breaches the pulp chamber in the middle of the tooth, the tooth's pulp (its nerve) can become inflamed and infected. This often requires a root canal (when the infected pulp is removed), before the tooth is restored with a filling and a dental crown—a far more significant restoration. This can be uncomfortable and requires extensive treatment that could have been avoided with a filling earlier on.
In short—just because a filling can take years to develop, it doesn't mean you should wait for years before seeking treatment.
For more information on teeth restoration, contact a dentist near you.