Milling

Millability is not the same for all zirconia

Zirconia blanks examined

  • Argen/ Sagemax Nexx ZR
  • Crystal Diamond HT
  • BruxZir milling blank
  • Wieland Zenotec ZR
  • ZirkonZahn ICE TR
  • Dental Direkt
  • Metoxit

Milling tests: handling the CAM system / analyzing the g-code

Example: DelCan milling track

Milling tests:

 – to improve the efficiency & optimize output of your milling

...before, with incorrect milling template

...after KEROX fine-tuned milling template (150 micron)

Adjusting RPM, feed rate, mill depth, # of flutes/edges: dramatic improvement on the cervical edge of the restoration.

Besides milling strategies, burrs are equally important

Milling strategies and burrs

General strategy
(Optimal for Roland DWX-50 and Zyclon CAM. This is only a recommendation, check with you milling machine manufacture for recommended milling strategies)
Tool Milling process S, rpm Liquid cooling F/XY (mm/min) F/Z (mm/min) Cutting depth ap, mm Overstep ap, mm Number of cutting edges
T1 Roughing A0 27 000 Ø 2 000 800 1.5 Max 1 2
T1 Roughing A180 27 000 Ø 2 000 800 1.5 Max 1 2
T2 Pre-finishing A0 30 000 Ø 1 500 800 1.0 Max 0.2 2
T2 Pre-finishing A180 30 000 Ø 1 500 800 1.0 Max 0.2 2
T3 Finishing A0 30 000 Ø 1 000 800 0.3 Max 0.1 2
T3 Finishing A180 30 000 Ø 1 000 800 0.3 Max 0.1 2

But the correct milling templates are only half of the battle – use the right tool geometry

Staining

Paint tests in Kerox reference lab:

Kerox ZircoStar® blanks match perfectly with corresponding VITA shades and all other reputable manufacturers:

  • Kerox & E4K
  • ZirkonZahn / Prettau
  • Origin
  • Upcera

Layering / Veneer tests in Kerox reference lab:

  • Degudent Cercon Ceram Kiss
  • Ivoclar E-MAX
  • Heraus

*All other major brand show perfect results

Sintering

Example: Cut sinter times and energy use

In case of over firing: stability decreases