Yamamoto and Lee – Roseville Family Dentists

What is an onlay? Dentists use onlays to fix badly broken down or weakened teeth in the back of your mouth.  Sometimes, back teeth have cusps which are broken, decayed or cracked to the point where a filling will no longer adequately fix it.  Crowns and onlays can properly fix these teeth because they are made outside the mouth where we can use stronger materials.

The difference between crowns and onlays is that crowns cover the entire visible part of the tooth, all the way to the gumline.  But onlays cover only the broken or weakened parts of the tooth.  The advantage of doing an onlay is that more of your natural tooth is left intact.  We make onlays using either gold or porcelain.

Cerec one-day porcelain onlays are made using CAD-CAM technology.

• An infrared camera takes 3D pictures of the tooth, both before and after it is prepared for the onlay.
• Our dentists then design the onlay on the Cerec computer.  (In many offices with this technology, the assistants design  the onlays.)
  
• The computer then wirelessly directs a milling machine to cut the onlay from a solid block of porcelain.  Since this can all be done in the office, Cerec onlays can be completed in one visit, with no need for a temporary restoration.

Compared to gold onlays, Cerec onlays are much more esthetic- they look like natural teeth! Usually porcelain, being a type of glass, is more brittle and susceptible to breaking than gold.  In order to minimize breaking, we meticulously bond them to the teeth so they can be strengthened and supported by the remaining tooth structure.  Because of this, studies show the success rate of Cerec onlays are comparable to gold.

Can Cerec be used to make full crowns?

Yes it can, but we choose not to in most cases.  With less remaining tooth structure to support the porcelain, Cerec crowns are more susceptible to breaking, even when they are bonded.