As we all know, we have a lot of new materials to pick from – and yet sometimes “old friends” are the best thing for us to remember.
Two of those old friends I am referring to are PFMs and full gold crowns. While the use of PFMs and full gold crowns has decreased, there are still situations where PFMs are the restoration of choice. First let’s talk about PFMs. While blocking out dark preparations is certainly possible with high opacity eMax ingots, the input I have received from my lab is that there is still a chance of show-through with extremely dark preparations like those pictured.
When are PFMs the Best Choice?
Cases like this, while extreme and likely rare in most practices, are examples of cases in which PFMs can be your best choice. This is due to the fact that the metal coping will completely block out all the underlying discolored tooth structure and take it out of play. Of course, one of the big challenges when using PFMs, particularly in the esthetic zone, is that they require a technician who is used to working with them and can predictably deliver a highly esthetic result
The reason I say this is a challenge is with the increased popularity of all ceramics, the number of technicians able to predictably deliver highly esthetic PFM restorations that can match the esthetics of an all-ceramic crown has greatly decreased. Another huge challenge is that while typically both a PFM and all-ceramic crowns require the same amount of reduction for an ideal result – at least if you ask the technicians I work with – the results with PFMs are more severely impacted by minor short comings of room for porcelain than all-ceramics.
The other “old friend” I would like to discuss is a full gold crown. While they are also decreasing in popularity, perhaps even more so than PFMs, they are a great choice in heavy bruxers when esthetic demands allow. Sure, we have things like full contour zirconia and eMax that do very well, but the fact of the matter is they still can and do fracture on occasion while gold does not. Sure, gold wears and your patients can even wear a hole though it over time but the simple fact is you can spot and deal with that easier than if your patient’s crowns fractures in half suddenly.
John R. Carson, DDS, PC, Spear Visiting Faculty and Contributing Author www.johncarsondds.com