Inlays represent an indirect restorative modality that is rooted in the same conservative philosophy as adhesive dentistry. They are primarily made of composite material or ceramic. Unlike a direct filling (performed directly at the chairside), an impression of the dental cavity is taken, and the missing portion of the tooth undergoing treatment is created in the laboratory. This results in superior physical and mechanical characteristics compared to a simple filling, while preserving a significant amount of dental tissue (and money) compared to a full crown. They are reserved for cases where large portions of the tooth have been lost due to decay or fracture (cracked tooth syndrome).

One of the key features that makes inlays a truly conservative therapeutic approach is the ability to maintain the vitality of the tooth, without resorting to root canal therapy, which is often necessary when placing a full crown on the tooth.