Sandblasting fully anatomic lithium disilicate crowns with Renfert’s Basic quattro IS. A field report by Oliver Brix, Bad Homburg in Germany.
When you think about sand-blasting images of leftover investment material, dull or roughened surfaces and moulds spring to mind. But sand-blasting is much more than this. Because the more precise a sandblaster operates the more flexibly it can be used, like Renfert’s Basic quattro IS for example. In this field report Oliver Brix shows us how even occlusal surfaces of IPS e.max CAD crowns in a blue condition can be formed.
Sandblasting has become an integral part of the daily lab routine. There could be no removal of muffle traces in the casting and pressing techniques without sandblasting. Precise conditioning or removal of impurities also belong to the job of a modern sandblasting unit. However the precise preparation of occlusal surfaces of ceramic crowns through sandblasting is relatively unknown (Fig. 1).
Fissures and occlusal surfaces can be easily accentuated using a suitable sandblasting unit like the Basic quattro IS with a fine abrasive (Cobra, AL2O3, 25 μm), as well as a fine 0,4 to 0,6 mm nozzle (Fig. 2 to 4). We have been applying this process successfully in our lab for many years. (Fig. 5 + 6)
In order to apply this process successfully it is important to have a sandblasting unit without any lead and follow-up times that can begin and end the process immediately and precisely. This way it is guarenteed that only the surfaces that are to be treated come in contact with the sandblast. The Renfert sandblaster guarantees this with its “Immediate Stop” functionality (IS), that’s where the name Basic quattro IS comes from.
However, the modification of monolithic IPS e.max CAD crowns (before crystalization) using sandblasting is a new differentiated approach. With a little practice it offers a modern and efficient working process for posterior teeth. The sandblasting technique described here opens up completely new possibilities to optimize the CAD/CAM based fabrication and functional dental prosthesis. The fundamental idea is to add missing details to CAD/CAM fabricated posterior teeth using sandblasting instead of a rotating instrument (Fig. 8 to 14). The details of this technique are described in the image galleries.
The technique introduced here distinguishes itself through great rationality and precision. The combination of digital workflow and manual perfection offers a real alternative to the classic manufacturing process. Of course we must mention that a waxed up and pressed monolithic crown continues to be the standard, but……”who knows”……
This blog article was published in the dental publication dental dialogue -Das internationale Journal für die Zahntechnik issue 08/2015
More on the Basic quattro IS and the rest of Renferts Basic sandblasting family www.renfert.com/basic