Crown me

My last visit to the dentist revealed a filled tooth that showed some cracking.  The filling was rather large so the recommendation was to get a crown instead of filling the tooth again.  Having one crown already I wasn't too happy about needing a second one.  This crown was made by a different process than my previous one.  the dentist referred to this as a CEREC crown after the technology used to make it.  Of course it has a Wikipedia page.    I found the process very interesting and document some of it below.

The tooth was shaved and prepared in basically the same way as for my other crown.  After that was done several images were taken of the area around where the crown would be placed.  The photo below is a computer rendering of my lower right jaw.  The blue outline was drawn by the dentist to define the location of the crown.

Once this was done the computer chewed on the images and produced a first pass at the crown.  The dentist then manually adjusted the shape of the tooth by grabbing and dragging.  Some areas were smoothed over and others were built up.  In the image below you can see the final image of the crown as it sits in my jaw.  The blue areas indicate contact between the crown and the adjacent teeth.

Here you can see the crown by itself without the other teeth.

Once the final design was done the image was then positioned inside the block from which it was to be milled. 

Reminds me a bit of the artists who believe that there is a statue inside a block of marble and it is their job to chip away until they find it.  Once the file was sent over to the milling machine it took about ten minutes to finish the job.  The process pretty much resumed from here in fitting the crown and seating it properly.  The only extra thing here was the 20 minutes or so wait while the crown was baked to harden the material.  Being the nerd I am I wonder if I should have asked for the function that defined the surface of my new crown. 

In total the process took about two-and-a-half hours.  Probably a little bit longer than the other method of crowning a tooth but this only took one visit.  I enjoyed the design and milling processes and seeing the equipment, but still am not too thrilled about needing a crown.  Guess I need to more careful taking care of my teeth.