Bob Conte Dentsply’s Celtra Duo is a new class of material known as “zirconia-reinforced lithium silicate ceramic” or ZLS. The crystalline matrix is considerably finer than lithium disilicate. The 10% content of zirconium oxide is virtually dissolved at the molecular level resulting in some unique properties. Because of the fine matrix, Celtra Duo can be milled in its final crystallized state and at its original strength of 420 MPa. Once milled the material can be polished and delivered at 210 MPa, which is higher than traditional glass ceramics. If desired the material can be glaze-fired for approximately 12 minutes bringing the material up to 370 MPa, suitable for most posterior applications.
The physical properties of the material lead to a block that mills very fine, with no marginal chipping. The fine ZLS microstructure allow for nice translucency and in-depth opalescence and fluorescence. Characterization can be added with Dentsply’s stain and glaze kit. The 10% dissolved zirconium provides for a rather radiopaque restoration on x-ray. Overall, a very nice block soon to hit the US market.
