Cerec – Day 2…

June 21, 2010

We started by reviewing the processes for using Cerec Connect for both the dentist and the laboratory.  Again, I feel the use of the system is pretty straight-forward.  There are a few minor idiosyncrasies related to the tracking of the order numbers, but nothing that should discourage any potential users.

Next on the agenda was a review of the lab scanning processes for both the Blue and Red Cams.  Again, nothing earth-shattering.  I did find it interesting that our instructor stated, unequivocally, that one should never force the stitching of the various images.  In other words, if the software won’t perform the stitching automatically, there is something wrong with your scan.  Its evidently a bad idea to override the software and drag the offending image into place.  Whether this is common knowledge for more experienced Cerec users, I don’t know.  All I can say, is no one ever previously made an issue out of it to me.

After lunch, we had our first look at the new v3.8 software with Biometrics.  It was interesting, but not quite the revolutionary advancement I had been expecting.  If I am correct, Biometrics replaces Dental Database and uses the surrounding dentition to create the software’s initial proposal.  One can also select a particular tooth from the scanned imagery as a basis for proposal.  We were shown three cases – a bicuspid, a lateral, and two centrals.  The neighboring anatomy around the bicuspid was sufficiently bland that it was difficult to get a real feel for how well the software worked with respect to posterior morphology.  The lateral proposal was pretty good, requiring only some minor tweaking to get a nice result.  The two centrals demonstrated a new wrinkle, and a flaw that surprisingly was not addressed in this update.

As the case was scanned without a pre-op or diagnostic wax-up, the designer was reliant on the BioMetric software.  He started with #8.  This sequence demonstrated a weakness in the software.  Because the data the software used to analyze the surrounding dentition included the prep form of #9 rather than the full contour image, the software read the mesial surface of the preparation of #9 as the mesial surface of a full contour central resulting in an overextended mesial surface for #8.  Not a huge deal, as the designer could easily use the Scale tool to correct the proposal.

The flaw that I would like to see corrected is the absence of a scaled grid overlaying the scanned images.  It would have been very easy to position the images of the two preparations with respect to the grid to identify the midline.  Instead, the instructor used the Distance tool to measure the distance between the mesial surfaces of the laterals.  He struggled a little to place the endpoints of the Distance measuring tool correctly – the grid(something available on 3Shape) would have been simple and fast.

The new wrinkle enabled by the BioMetric software is that one now has two tools available to match the proposal for #9 to that of # 8.  It is still possible to use Correlation and mirror-image the likeness of #8.  Or, one can simply have the BioMetric software analyze the surrounding dentition – including the proposal for #8 – and determine the appropriate contour.  I like this second approach.  I know about bilateral symmetry, but in my observations, its rare, -if it exists at all – in natural teeth.  By allowing the software to determine the contour using input from the surrounding teeth, I think you will get subtle differences that will help create a more natural smile.

Finally, the instructors gave a very good explanation of all the parameters available to the designer, and how to go about setting them to achieve the best results for your clients.  It was stressed that one can’t really simply copy parameters from someone else, as there are always differences in processes, i.e., stone expansion, degree of powdering, individual doctor’s preferences, etc…

This week is going to be busy due to vacations.  I’m hopeful of using the knowledge gained to fine-tune my Cerec results in the near future, and will share the results at a later date.

© 2010, Jeff Saylors. All rights reserved.