Inlays and On-lays
Inlays and on-lays can be made of gold or porcelain, or a simple composite resin. These pieces are bonded to the damaged area. Inlays, which are similar to a dental fillings, are used inside the tips of the tooth, an On-lay is a more intense reconstruction that is similar to the inlay, but extends out and over one or more of the cusps of the tooth/teeth.
Normally, gold has been the material of choice for inlays and on-lays. Lately, however, porcelain has become very popular due to its durability and natural tooth/teeth color matching potential.
Inlays and on-lays require two appointments to complete the procedure. In your first visit, the filling being replaced or the damaged or decaying area of the tooth is cleaned out, and the tooth is prepared for the inlay or on-lay. To provide a perfect fit and bite, an impression of the tooth is taken, and sent to a lab for fabrication. The doctor will then apply a temporary sealant on the tooth and schedule the next appointment.
Next (the second appointment), the sealant is removed. The dentist will then make sure that the inlay or on-lay fits correctly. If the fit is satisfactory, the inlay or on-lay will be bonded to the tooth with a strong resin and polished to a smooth finish.