An aesthetical filling will not suffice when more than half of a tooth is missing due to tooth decay. In this case, it's recommended to make an inlay or onlay. The inlay fills in the cave of the tooth, the onlay covers the whole occlusal surface. Your dentist prepares the tooth for inlay or onlay and makes an impression of it, then the dental technician prepares the solid inlay or onlay which is cemented into the cavity. As a result, the shape, anatomical function and aesthetic appearance of the tooth can be fully restored. It is a long-term investment, its life expectancy can be up to 8-12 years.