I think it really depends on the design of the connection of the implant. When you look at an Astra zr abutment, the connection is paper thin. We've been involved with studies of Astra implants, and during these I've seen a number of them fracture at the connection level. When you compare them with Straumanns Bone Level implant, the connector is much more robust. I believe we have done some Straumann screw retained zr abutments with the bone level implants and haven't had any failures. I believe the thicker you can make the implant, especially where a ti screw will be torqued onto it, helps out a lot. With all that being said, my preference is to do a hybrid. The best selling point to the doc being that they are torqueing ti screw to a ti interface. If they have doubts about the zr cementing to the incert ask them if they have ever done a solid abutment and cemented a zr crown to it? The only hurdle in the way of hybrids abutments really taking hold, is the implant companies that are telling docs that this will void any warranty. I remember when we first got our Etkon scanner, went to Arlington for training the Straumann reps were all "why would anyone want to GLUE zr to ti" now look, they are offering the same thing. This is I feel a better solution, a stronger solution for the long run.
