Traditional fillings can reduce the strength of a natural tooth by up to fifty percent. As an alternative, inlays and onlays, which are bonded directly onto the tooth using special high-strength resins, can increase the strength of a tooth by up to 75 percent. So, while fillings make for a quick and convenient fix, they aren’t nearly as durable or strong as inlays or onlays. As a result, they can last from 10 to 30 years. In some cases, where the damage to the tooth is not extensive enough to merit an entire crown, onlays can provide an excellent alternative.