There are times when fillings cannot reinforce a tooth enough, but a crown is not needed. A Dental Onlay or Inlay is the best solution.
Inlays and onlays are known as indirect fillings because unlike a standard filling, both are made in a laboratory and cemented or bonded to the surface of the tooth during a second visit. Unlike standard fillings, inlays and onlays do not weaken the tooth structure, but actually strengthen it. After the procedure, the tooth can bear up to 50 - 75% more chewing force.
Because both are fabricated in a dental laboratory, it usually takes two or more appointments to restore a tooth with a porcelain inlay or onlay.