Not all cavities are the same, and this isn't necessarily anything to do with the size of the pesky cavity in question. Any cavity requires treatment (and the sooner you get treatment, the better off you'll be), but its location on your tooth can play a role in just how serious the cavity can be. A cavity that develops at the base of a tooth can be especially problematic.
Enamel and Cementum
Your dental enamel protects the visible portions of your teeth. Of course, your teeth extend further below the gum line, and that's where your cementum takes over, serving a similar purpose to enamel. This cementum protects the roots of your teeth, and when it's compromised to the point that a cavity develops, this is what is known as a root cavity.
Sensitivity and Discomfort
Dentists are often the ones to spot a root cavity during one of your regular checkups (which is yet another reason why it's important to regularly visit your dentist). Unlike a cavity that develops in the crown (the visible section) of a tooth, a root cavity might not be obvious to a non-professional. However, you might feel it, even if you can't see it. You will notice an increased level of sensitivity as your roots are exposed, and this can be uncomfortable.
Your Pulp Chamber and Infection
It's important to treat a root cavity as soon as possible. If the cavity continues to deepen, it may breach your tooth's pulp chamber, which is where the tooth's nerve is found. This process can result in an infection of the nerve, which often requires a root canal. Additionally, if the cavity is permitted to extend further beneath the gum line, it can be necessary to actually cut into your gum tissue to access the cavity in order to repair it. Early treatment spares you from these more intensive forms of repair.
Treatment for Root Cavities
Filling a root cavity generally requires the same approach as filling a cavity on the upper sections of a dental crown. Your dentist will remove the deteriorated portions of the tooth before filling the cavity with an appropriate material that is colour-matched to the surrounding tooth surface. It's quite simple, although is arguably a more urgent problem than a cavity elsewhere on a tooth, and this is because of the cavity's proximity to your tooth's root.
A root cavity isn't a serious issue in its early stages, although it can become serious if it's not treated quickly.
To learn more, contact a dentist.