When damage to one or more cusps compromises a tooth's structure, a dental onlay rebuilds it to its optimal shape, appearance, and function. If the tooth's structure is weak and could crack if filled with traditional filling material, your dentist may recommend an onlay. This treatment helps to restore optimal shape and function while saving as much of the natural tooth as possible. With the help of digital technology, a custom onlay can be fabricated while you wait. First, a numbing agent is applied to the area, and your tooth is prepared to make room for the onlay. Then, using an intraoral scanner, the prepared tooth is imaged to aid your dentist in designing the restoration. When your permanent onlay is ready, your dentist makes final adjustments, bonds it into place, and smooths any rough spots. Once completed, your tooth is restored to optimal strength, function, and appearance.