A Cerec crown failure. Brand or Technique problem?

Cerec is a brand of Cad-Cam machines which mill out porcelain crowns while the patient is waiting in the office.  The concept is marvelous because who would not want to walk home with a brand new crown in just one visit?  Let’s talk about this…

The sequence of treatment of a cad-cam fabricated crown would be:

1.  The dentist prepares the tooth for the crown.

2.  The tooth structure is scanned into the computer using a special camera.

3.  The computer activates the Cerec machine to mill out the crown.

4.  The dentist cements or bonds the crown onto the tooth.

This Xray shows a molar with a Cerec crown that crumbled during dinner one night… What went wrong?

Upon repairing the tooth I discovered some obvious problems:

1.  There was extensive decay in the tooth structure underneath the crown.  This could have severely compromise the strength of the bond and could have caused the crown to come loose over time.

2.  The existing root canal on the tooth was under-filled.

3.  The gum tissue around the remaining tooth structure was extremely inflamed.  This is a sign that the junction between the tooth and the crown was not properly sealed.

When choosing dental work, it is important to not base your decision on a “brand”.  Instead, it is crucial to find a dentist who delivers dentistry with strong emphasis on technique.

A crown on a tooth will only last if the following are handled properly:

1.  Proper technique in treating the tooth with a root canal when needed.

2.  Proper technique in building up the tooth structure underneath after the root canal.

3.  Proper technique in scanning the tooth structure.

Technique, technique, technique !

Good dentistry is all about good old-fashioned health care.  Treat brands with a grain of salt.  With a little bit of research you will discover your key to a long lasting dentition.


Alex Nguyen, DDS is a Saratoga Dentist who practices General Dentistry, Cosmetic, and Implant Dentistry. For over 20 years the practice has been serving the residents of Santa Clara County and San Francisco Bay Area.

About alexnguyen

My career passion is to help enhance, restore, and preserve people's smiles View all posts by alexnguyen

One response to “A Cerec crown failure. Brand or Technique problem?

  • Doug Decker DDS

    Hi Alex, Doug Decker DDS here–grew up in Los Gatos and practicing in San Diego for 30+ years. I see people all the time with CEREC crowns that are not “failing” but have open contacts, open margins, or excess cement. The pt. is not even aware there is a problem! The reality is they are very difficult to do and once you have a payment on a $100,000 hammer(the CEREC machine), everything looks like a nail(CEREC onlay/inlay/crown). Thanks. Doug

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