How long does an emax crown last?

For restorative dentists choosing between monolithic emax and layered feldspathic alternatives, the longevity conversation starts at the lab, not the chair. Monolithic lithium disilicate pressed or milled to full contour maintains fracture resistance between 300 and 400 MPa, which is roughly two to three times the strength of feldspathic porcelain. That number holds only when the axial wall reduction meets manufacturer spec (1.5 mm minimum) and the internal fit is within 50 to 80 microns. A loose fit accelerates cement failure and chips the margin long before the material fatigues.

Layered emax, where the core is pressed lithium disilicate and the facial surface is hand-layered with fluorapatite ceramic, introduces a second failure mode: delamination. The 10-year survival data for layered emax drops 5 to 8 percentage points below monolithic in high-load posterior zones. For anterior cases where esthetics require the layered build, the lower occlusal stress makes delamination far less common. Matching the build strategy to the position is the clinical decision that most directly affects how long the crown survives.

Dani Dental fabricates emax in both monolithic and layered configurations. Monolithic units ship milled from Ivoclar IPS e.max CAD blocks, characterized and glazed in-house. Layered anterior cases move to the ceramics bench, where the technician handling the case is the same person on the phone if the shade reads differently at seating. Turnaround on single-unit emax runs 5 to 7 business days from a confirmed digital impression.