How deep a chamfer or shoulder is needed for full thickness zirconium or lithium disilicate crown?
Dentists, like most people, are creatures of habit. For many years we have been told by laboratories to provide 1mm shoulder or chamfers for our ceramic crowns. While this may make it easier for our labs to fabricate restorations, but now that they are predominantly fabricating milled zirconium and lithium disilicate restorations this amount of chamfer depth is more than the minimum needed. For those of my readers who are wondering what a chamfer or shoulder refers to, it is a shelf that provides the finishing line for this type of restoration. Since this area is not the part of the restoration that has to deal with occlusal forces, probably all that is needed is about a .5mm deep chamfer (or shoulder). Since conserving tooth structure can ultimately influence the success or failure of a crown and the tooth supporting, preserving tooth structure is very desirable. The deeper our chamfers are, the closer we get to a tooth pulp when we are preparing a vital t...