When a cavity has extended into the nerve of a baby tooth and the nerve is still healthy, it is best to save the tooth. When a nerve is exposed in an adult tooth, normally a root canal would be performed. However, since a baby tooth will only be in a child’s mouth for a few years, there is no need to do an expensive treatment like a root canal. A procedure called a vital pulpotomy is recommended. In a pulpotomy, the top portion of the nerve is removed leaving only the remnants inside the roots behind. The remaining nerve stump is treated with a medication to stop the bleeding. The most commonly used medicament is formocresol, although ferric sulfate, calcium hydroxide, or mineral trioxide aggregate have also been tried with varying success. Formocresol will not only stop any bleeding, but also mummifies the tissue effectively sterilizing it and keeping the underlying nerve alive and vital. The area is then covered with a base such as zinc oxide and eugenol, calcium hydroxide, or glass ionomer.
In children, cavities tend to grow much quicker than they do in adults. This may be due to their immature immune systems not being able to keep the cavity producing germs at bay, the tendency toward a higher sugar content in their diet, and their lack of manual dexterity to properly clean their teeth. With the relatively rapid expansion of decay coupled with the small size of the baby teeth, it is not uncommon to see a cavity reach all of the way to the nerve. Once that happens, a decision has to be made on whether to restore the tooth or to extract it. If the tooth still has a healthy nerve, then it is usually best to save the tooth if it is restorable. Front teeth aren’t as important in maintaining space, so they can be removed without regret other than the cosmetic aspect. If the tooth does have to be extracted and it is a back baby tooth and it will still be more than a year before the permanent tooth is expected to erupt, then a space maintainer must be cemented in place to keep the permanent teeth from shifting.