Inlays and onlays are typically not terms that your average person is familiar with. A non-dentist can only guess their meaning, but a dentist or a dental student will be thoroughly aware of their benefit. Inlays in dental terminology is a kind of filling which is fitted into the tooth cavity and bound there. An onlay is similar to an inlay except the fact that it is used outside the tooth to cover the cusp area of the tooth. The cusp is the pointed part of the tooth on top.
When it comes to the material, porcelain is the best choice. Porcelain inlays and onlays work better in case of larger metal fittings and cavities. They are also more attractive as porcelain can be matched to your tooth color.
A porcelain-made Inlay or onlay is a customized insert that is shaped to fit inside the tooth. It is firmly fitted in place and prevents further decay of the tooth.
Traditional filling is done directly within the cavity and then hardened which often leads to shrinkage of the material. It can create minimal gaps during the process which may lead to destabilization later on. On the other hand, the Porcelain Inlay/Onlay is first hardened and then inserted into the cavity to eliminate further tooth decay and make the tooth more stable. Porcelain Inlays/Onlays are called indirect restorations as an expert is required to make them, so a second office visit is necessary for carrying out the process, while the dentist performs the traditional filling in the first visit.