Dr. Ramit Lamba
Full mouth rehabilitation with zirconium Crowns-Digital part of Dental Laboratory.
ALL CLINICAL CASES
There is always a fear of giving long span zirconium bridge. Monolithic Zirconia crowns are certainly the option in long span bridges, but the aesthetics are compromised in comparison with the manual multilayering porcelain crowns. Keeping certain points in mind you can make it a success.
Case Study
A 58 years old male pt. came with partially edentulous state and was not willing for implants/ removable Prosthesis.
CAD PART: Designing was done in such a way to provide high strength with optimal Aesthetics. Full contour design was done with labial and buccal cutback for layering.
Total thickness of connector in anterior region has been established 10+ mm and in posterior 14+ mm.
Other Calibrations
Minimum thickness of coping: 0.8 mm
Cement gap:0.03mm (Has been increased)
Extra horizontal and vertical gap:0.1 mm (Has been increased)
Margin: 0.2 mm
Emergence angle: 75
Same insertion axis was set for all teeth.
CAM PART : 98×18 mm zirconia blank has been used for milling. Sintering support is designed in CAM Software. Sintering support helps in uniform shrinkage of bridge during sintering and thus minimizing the risk of ill-fitting or rocking.
PRE SINTERING: Bridge is separated from zirconia blank by cutting sprues from outer ring. Sprues attached to sintering support are reduced to 50 percent thickness. Bridge with sintering support is coloured by dipping and brushing technique.
SINTERING: Heat rate is modified to make gradual heat rise and slow cooling. Heat rate of 4 degree Celsius / minute up to 700 degree. Hold time 1 hour at 700 degree Celsius..
Heat rate 5 degree Celsius/ minute up to 1300 degree Celsius. Hold time 1 hour at 1300 degrees.
Heat rate of 3 degree Celsius/ minute up to 1450 degree. Hold time 2 hours at 1450 degrees.
Natural cooling is established with chamber 100 percent closed till temperature is dropped down to 900 degrees. Chamber Lift is 80 percent up (close to heating chamber) at 700 degrees and chamber lift is 40 percent at 400 degrees.
POST SINTERING: Bridge is detached from sintering support by removing all the sprues.
Check the fitting on model
Upper and lower teeth in occlusion
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ALL CLINICAL CASES
