Dental inlays and onlays are ideal when the damage/decay to a tooth is neither severe enough for a dental crown nor bad enough that a filling is not possible. While inlays help prevent further damage/decay to a tooth’s upper surface (enamel) inside the tooth cusps, onlays are needed if the tooth decay extends out to one or more of the cusps.
Although inlays and onlays can be made of gold or composite resin, using porcelain is more advantageous due to its strength and ability to match the tooth’s natural color.
Inlays and onlays are a good alternative to traditional fillings because they are both more aesthetic and strengthen weakened teeth. Whereas fillings can reduce a natural tooth’s strength by up to 50%, inlays and onlays actually raise the tooth’s strength by up to 75% as they are bonded directly onto the tooth using special high-strength resins. Consequently, they can last decades.