Fig. 1: Great White Z diamond coated burs utilised for zirconia crown removal or endodontic access and metal cutter carbide bur for use on all-metal crowns or the metal base of porcelain-fused-to-metal restorations.
Fig. 2: The diamond-coated bur is held against the buccal surface of the crown with light pressure and moved in a direction that is parallel to the long axis of the diamond-coated bur to create a slot through the ceramic.
Fig. 3: The diamond-coated bur continues to be used in a direction that is parallel to its long axis,
sawing through the ceramic until either dentine (ceramic crown) or metal (porcelain-fused-to-metal crown) is encountered.
Fig. 4: A slot is next cut across the occlusal surface in a similar manner that is continuous with the slot cut on the buccal surface, again moving the diamond-coated bur parallel to its long axis.
Fig. 5: Crown removal of an anterior crown requires the buccal slot to continue over the incisal edge to the lingual surface.
Fig. 6: A flat-bladed instrument tip is inserted in the buccal groove and
rotated left to right to create torque to split the crown at the slots.
Fig. 7: A round diamond-coated bur is used with light pressure to outline the access form desired.
Fig. 8: Once the crown material has been penetrated to the dentine in the outline form, access through the crown is completed.
Fig. 9: After access through the zirconia or ceramic crown with the round diamond-coated bur, a carbide bur is utilised to complete endodontic access to unroof the pulp chamber.
Fig. 10: Unroofing the pulp chamber may be accomplished with the diamond-coated bur or a carbide bur (practitioner preference), and the endodontic access is completed.
Fig. 11: The diamond-coated bur is used to create the slot in the ceramic to the metal substructure with a porcelain-fused-to-metal crown.
Fig. 12: The carbide bur is utilised to continue the slot through the metal to the underlying dentine.
Fig. 13: The slot has been completed through the porcelain-fused-to-metal material and is ready for insertion of the crown remover instrument.
Fig. 14: Following the outline formed with the round diamond-coated bur to the underlying metal substructure of the crown, the carbide bur is utilised to complete endodontic access to unroof the pulp chamber.