The emax 40mm block has opened up many options for us to complete single appointment anterior, posterior, and Maryland bridges.  Those of us who have done any of these procedures appreciate the ability to offer these services to our patients.  With that in mind Ivoclar has specific guidelines when using these blocks to help insure clinical success. 

First, it is recommended that ALL bridges, anterior or posterior, have connectors at least 16 sq mm.  This varies slightly from the JADA study released in March 2012.  That study reported a 100% five survival rate when a connector size of  12 sq.mm is achieved in the anterior and 16 sq.mm is achieved in the posterior.  That number drops to 88% after ten years when the connector sizes are followed as above. 

Second, Ivoclar suggests NOT placing these bridges any further posterior than a premolar abutment.  In other words, no molars, as abutments or pontics.

Finally, it is recommended for single pontics only, never more.

Again, these are the guidelines direct from Ivoclar.  Many of us have pushed these limits.  Only time will tell.