Assessment of Diamond Rotary Instruments Advertised for Cutting 3Y-TZP Restorations. A Scanning Electron Microscope Analysis

Aim: To examine the cutting efficiency and amount of material removed from crown-cutting diamond burs from a different manufacturer on zirconia using an electric handpiece. Material and Methods: The performance of super coarse diamond bur round-end from five different manufacturers that were commercially advertised as zirconium crown cutters were assessed. The five manufacturers and their respective diamond bur models tested were super coarse Group 1: Dimond bur, Group 2: Zirconia Diamond Bur, Round End Cylinder, Meisinger, Group 3: 4ZR Zirconia Cutter Diamond Crown Removal Bur, Group 4: Brasseler Dental Diamond Bur, Group 5: Expanded SS White® Lineup of Zirconia Cutting Diamonds. The qualitative assessment of diamond burs (before zirconia cutting) and (after zirconia cutting) was assessed using a scanning electron microscope. The mean cutting distance and material removed for each group were calculated and analyzed using one-way ANOVA. Results: The highest cutting efficiency was found in group 2 and the lowest efficiency was observed in group 5. Post-SEM images of rotary zirconia cutting instruments in groups (Post G1-G5) demonstrate pullout, wear, chipping, and loss of the diamond grains in general. Conclusion: Zirconia Diamond Bur (G2) was found to be suitable. Whereas, (G5) Expanded SS White® Lineup of Zirconia Cutting Great White®Z Diamonds is less effective.