Sameer Puri One of the main reservations that some clinicians have had with regards to switching over to CEREC is that they feel that the preparations for all ceramic restorations are unnecessarily aggressive. No doubt that you need an adequate thickness for traditional ceramic restorations to work well. Naysayers argue that you can leave gold thin as 1mm, thereby conserving valuable tooth structure. CEREC restorations by comparison have required 1.5 to 2.0 mm of occlusal reduction for the materials to have a chance at longevity.
Things however have started to change recently. Ivoclar has been testing emax at 1.0mm occlusal thickness. This has worked well in their results and although they have come officially out and said that they recommend a 1.0 mm occlusal thickness, there is sufficient anecdotal evidence that a 1.0mm thick emax works just fine.
Conversations with our members has shown that many are pushing the limits of emax and leaving it 1.0mm thick and having no negative effects.
Perusing through the Vita Enamic brochure, I found this schematic a bit interesting. Vita, with their new hybrid ceramic is actually recommending a 1.0mm thick reduction. The nature of the material allows it to be left thin and we will supposedly have success with this. I think this is going to have reverberating effects in the world of CAD CAM. 1.0mm thick occlusal reduction is a monumental step forward and for Vita to go out on a limb with this material and recommend 1.0 is significant.
Time will tell if our restorations will last as well at 1.0mm as they have done at 1.5. However, I feel this is a step in the right direction.
Screen Shot from Vita Enamic Brochure
