Inlays and onlays are restorations that fall between fillings and crowns in size and purpose. At Austin Longevity , we use inlays and onlays to repair teeth that have damage too large for a traditional filling but not severe enough to require a full crown. Made from porcelain, gold, or composite materials and fabricated outside the mouth, they offer a more durable and conservative restoration option than large fillings while preserving more natural tooth structure than crowns. The difference between inlays and onlays is the area they cover. An inlay fits within the cusps (the raised points) of a back tooth, similar to a filling but made in a lab for a more precise fit. An onlay covers one or more cusps in addition to the area between them, extending up over the chewing surface to protect a more significantly damaged tooth. Onlays are sometimes called partial crowns because they protect a substantial portion of the tooth without covering the entire visible surface like a full crown. Modern inlays and onlays are typically made from porcelain or zirconia, which look natural and bond strongly to the tooth. The procedure usually takes two visits: the first for tooth preparation and impression, the second for placement of the lab-made restoration. Some practices offer same-day inlays and onlays using CEREC or similar in-office milling technology. With proper care, inlays and onlays typically last 15 to 30 years, often outlasting traditional fillings significantly while preserving more natural tooth than crowns require.