Zirconia Crown Separating And Finishing
The correct choice of grinding instruments is imperative for finishing the restorations. This is true for both sintered and non-sintered objects. The use of unsuitable milling and grinding instruments may lead to local overheating of the material or to damage.
Attention: Wear protective gloves before separating the milled restorations. This is particularly recommended for restorations intended to be infiltrated with IPS e.max ZirCAD Colouring Liquids in a further processing step. Contaminated hands may leave a grease film or contaminations on the restorations, which may lead to an undesired shade result.
The following aspects should be taken into consideration when separating the restorations: – Non-sintered zirconium oxide restorations are susceptible to damage and fractures. This fact has to be kept in mind during the entire working procedure. – Any post-processing should be carried out in the non-sintered state. – In the non-sintered state, any contact with unsuitable liquids and liquids not approved for zirconium oxide (e.g. unpurified water and/or lubricant coolant) and/or contact media (e.g. occlusion spray) must be prevented. – Use only light pressure for finishing. – Do not, under any circumstances, post-separate bridge constructions with a separating disc. This may lead to predetermined breaking points in the area of the connectors and reduce the strength of the all-ceramic restoration. – Rubber polishers should not be used as these condense the surface and cause contamination. – Make sure that the minimum wall thicknesses of the restorations are maintained during finishing.
– Clean the restoration thoroughly after finishing. To remove zirconium oxide dust, carefully clean it with a soft brush and then blast with oil-free compressed air.
– Adhering zirconium oxide dust may be sintered to the restoration and lead to fitting inaccuracies.
– The non-sintered restoration must not be cleaned in an ultrasonic bath or with the steam jet.
– The non-sintered restoration must not be blasted.