Generally we want to rid the mouth and the tooth of any decay. However, sometimes when doing a filling or a restoration we may elect to leave a very small amount of the cavity, or decay, on that tooth.
Everyone seems terrified of the dreaded cavity! It just sounds scary and gross. Many people don’t realize how non-invasive a filling can be when treating a small cavity or even multiple small cavities.
I never understood why so many members of our population hated going to the dentist when I was younger. As I started assisting for my own family dentist, I saw the phobia manifesting in patients.