An onlay, with today’s advanced dental materials and knowledge, lets us prepare and shave much less structure than a traditional crown. Why? Because a traditional old school crown would need mechanical retention to hold on to your tooth and therefore the tooth will need much more reduction. Also, a traditional crown would easily come of compared to an onlay that is bonded (chemically retented to the tooth, therefore, under a knowledge clinician’s supervision, technically becomes a part of the tooth)
The Advantages of Onlays over Crowns
A crown can reduce up to 60-70 % of your tooth structure and reduce your enamel entirely, which is the outer and strongest shell of the tooth. Fun Fact: It is also known as the hardest structure in the body, even harder than a bone!
Meanwhile, an Onlay will need reduction or shaving of only necessary compromised parts of your teeth if done by a skilled and knowledgeable clinician who is trained in adhesive dental principles.
Also, a traditional crown would come off easier as compared to an onlay that is bonded (chemically attached to the tooth, therefore, under a knowledgeable clinician’s supervision, technically becomes a part of the tooth)!
This is what a tooth looked like after removal of a relatively well-fitted old school crown with mechanical retention and metal base. 60-70% of the tooth structure was removed already to achieve retention for the crown.
This is what a porcelain onlay looked like after removal of the porcelain. The strong enamel shell is protected and the tooth was only prepared (shaved down) where it was weak or decayed. Tooth is healthier and isolated with dentin sealing materials.
An onlay is the restoration of the tooth structures that cover one or more of the chewing functional surfaces of the tooth. What does this mean? Think of your tooth as a house. When a house looses a wall that is not a column that holds the house together, you can patch it up. When a house looses it’s load bearing column, it will likely collapse sooner or later. A tooth goes similarly. When it looses a part of it that we call a cusp, which is the tip of the back teeth that bear the load when you chew that medium rare steak, it looses it’s integrity and might crack or split. The onlay restores these load bearing parts of the teeth.
If the patient has good oral hygiene and the biting, chewing habits are optimized with the dentist, onlays have the proven ability to last over 15 years. Is that a guarantee? Unfortunately, not. But what we know is that it is unnecessary and against the law of medical ethics to shave down a tooth to a crown unless it is a necessity, due to certain but rare situations in modern dentistry.
Veneers can correct chips, gaps, discoloration, minor alignment issues, and other concerns you may have related to your smile.