When more than half of a tooth is damaged, we may advise replacing the damaged structure with an inlay or onlay. Many times these are conservative alternatives to crowns and fillings.
If the damage is minimal, inlays are appropriate. When the damage is more extensive (but not enough to warrant replacement with a crown) onlays may be best.
Inlays and onlays are made from porcelain, gold or composite resins that are bonded directly to the teeth. These materials are much stronger than traditional blended-metal fillings and can help prevent further decay or damage.
First, your dentist will remove the damaged areas (or old fillings). He then takes an impression, which is sent to a dental lab where the restoration is constructed.
After the inlay is completed, your dentist will check for proper fit, then bond the well-fitted onlay or inlay to your tooth with a strong resin.