What is a dental inlay, and how is it different from a filling? If you’re someone with a cavity, expert dentists from Tooth Crusader’s clinic will recommend one of these treatments as a way to restore a healthy appearance back to your teeth. Both of these simple procedures involve drilling out the decaying portion of the tooth and then filling the cavity. However, the difference lies in the type of material that is used to fill the cavity as well as how that material is attached to the teeth. Here’s a quick breakdown of dental inlay vs filling.