Ceramic Crack

Problem / Question

The pressed ceramic has cracks after pressing and divesting (before layering).

Cause (1)

The zirconia framework has cracks.

Solution / Answer (1)

Finish the zirconia framework without cracks and damages.

Cause (2)

The zirconia framework has been used too many times.

Solution / Answer (2)

The zirconia framework should not be used more than two times.

Cause (3)

The zirconia framework is too thin.

Solution / Answer (3)

The thickness of the zirconia framework is at least 0.4mm.

Cause (4)

Sprue-cutting position is too close to the crown.

Solution / Answer (4)

Sprue-cutting position must be at least 2mm from the connection of the crown and sprue.

Cause (5)

Excessive heat is generated during grinding at the morphological correction.

Solution / Answer (5)

Carefully grind the press ceramic without generating excessive heat.

Cause (6)

Fluoric acid was used to melt the press ceramic.

Solution / Answer (6)

Never use fluoric acid as it may melt the zirconia framework and weaken its strength.

Cause (7)

CZR shade base porcelain was used before pressing.

Solution / Answer (7)

Only CZR PRESS Shade Base Stain must be used before pressing.

Cause (8)

Sand-blasting pressure is too high.

Solution / Answer (8)

The pressure must be less than 29psi (0.2MPa).

Cause (9)

Baking temperature of shade base stain is too low.

Solution / Answer (9)

Observe the specified baking schedule.

Cause (10)

Other framework except pure zirconia framework has been used.

Solution / Answer (10)

Only pure zirconia framework should be used. VITA In-Ceram® ZIRCONIA cannot be used.