In the first of our CEREC series we will discuss one of the greatest benefits of the CEREC technology - "Crown in a Day".
What is a crown?
A crown is a permanent dental restoration that covers the entire tooth. A crown may be required for many different reasons: decay, fracture, wear, esthetics, establishing a proper bite, etc. The tooth is prepared into the proper shape so that a full coverage crown can be cemented on top of it and provide the tooth with appropriate support. Crowns give the tooth strength and are typically made out of ceramics or metals. Once cemented, a crown acts just the same as a normal tooth does.
Figure 1. Crown
Traditionally a crown requires a minimum of two appointments: one appointment to prepare the tooth for the crown and take the impression to send to the lab and then another appointment to try in and cement the crown permanently. This work flow has the possibility to extend into more time if the impression is not able to be taken on the day of crown preparation, or if the crown does not meet the necessary standards upon delivery and requires that it be sent back to the lab for adjustments. This method also involves a patient having to wear a temporary during the time they are waiting for their crown which can come with its own struggles- temporaries can sometimes fracture or fall off, and the temporary materials do not allow for as nice of esthetics as the final restoration.
CEREC technology allows all of this work to be done in just one appointment. During a typical CEREC crown appointment the dentist spends the first part of the appointment preparing the tooth for a crown. Once the tooth is prepared, the mouth is scanned and it creates a model within the software. The dentist will use this model to design a custom crown and once it is approved it is sent to the milling unit in the office. In the mill there is a block of crown material that is cut and shaped into the crown with great accuracy in about 10-15 minutes.
Figure 2. Scan of the prepared tooth
Figure 3. Designing the Crown
Figure 4. Milling Unit
Once the crown is done milling, it is tried into the patient’s mouth to confirm appropriate fit. Any adjustments and polishing is done at this time. The dentist also has the opportunity to stain and glaze the crown as needed to characterize it to match the rest of the dentition seamlessly. If the dentist finds any discrepancies upon try in such as inadequate fit or esthetics then they can make the necessary changes and re-mill a new crown in the same appointment if time allows.
Once both the dentist and the patient are pleased with the final restoration it is cemented in place and treatment is complete!