Comparison between the fracture strength and failure mode of lithium disilicate, zirconia and titanium implant abutments
Eighty implants (FairTwo, FairImplant, Germany) having a length of 11.5 mm and a diameter of 4.5 mm were used to be restored with single lithium disilicate crowns (IPS emax CAD, Ivoclar Vivadent, Liechtenstein). Five types of abutments were used; Ti titanium (CopraTi-4, Whitepeaks, Germany), Zr zirconia (Wieland Zenostar, Wieland Dental, Germany) with no titanium insert, ZrT zirconia with titanium insert, LaT lithium disilicate (IPS emax CAD, Ivoclar Vivadent, Liechtenstein) abutments and LcT lithium disilicate hybrid-abutment-crowns. All specimens of the titanium abutments (group Ti) as well as all abutments with titanium inserts (groups ZrT, LaT and LcT) showed similar modes of failure. They presented bending at the screw and internal connection of the titanium abutment or titanium insert without ceramic displacement or fracture.