I'm an adult but I still have a baby tooth. Can I keep using it?

A baby tooth in a spot where the permanent tooth is congenitally missing can keep serving you into adulthood as long as it is well cared for. Baby teeth have shorter roots than permanent teeth and loosen more easily, so the principle is to monitor them at regular check-ups and use them as long as possible. However, if one becomes significantly loose or comes out, that space has to be restored with an implant or another option, and checking the root condition on an X-ray in advance lets you plan when treatment will be needed.