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CAD/CAM and the digital workflowCAD/CAM and the digital workflow
Improved Materials
Lost wax casting
Hard ceramics
CAD/CAM system
Manufacturing methods Movement from lost wax casting to
dental CAD/CAM
Application of science to dentistry
CAD/CAM made it possible to work with a new generation of hard ceramics in dentistry. These materials cannot be cast so therefore must be machined. In order to machine something a cutting path is required. The cutting path is generated from digital scanned data.
SCAN THE OBJECT
CREATE DIGITAL DATA POINTS
GENERATE CUTTING PATH
MACHINE REPLICA OBJECT
Application of science to dentistry
CAD/CAMWhat is dental CAD/CAM?
Dental CAD/CAM is the process by which the model of a prepared tooth is scanned. This data is then used to generate the coping design (CAD) which in turn is used to generate a cutting path for manufacturing the coping (CAM).
Computer Aided Design (CAD) and Computer Aided Manufacture (CAM) in restorative dentistry can be used to:
Reduce production time for copings and frameworks; increasing overall productivity
Introduce consistent and measurable accuracy Provide evidence of product quality
CAD/CAM technology
Scanner- digital impression of the prepared teeth
Software – CAD- digital cast on the screen
- virtual design of the model Milling unit – CAM
- computer aided milling unit (cnc)- grinding process
Green processing Milling of presintered ceramic blocks advantage: easy to process, grinding instruments do not
have to be replaced that often disadvantage: porous presintered zirconia shape shrinks
during final sintering- enlarged substructures= software calculated
Hard processing Milling of dense sintered ceramic blocks Takes more time, grinding instruments wear off
HIP= Hot Isostatic Press : special sintering technique High temperature and pressure applied to densify the
material, gaining 20% more in strength
Frameworks zirconium oxide
In clinic - the dentist purchases an intra-oral scanner, the cutting machine and the consumable materials. All the work is done by the dentist at the clinic. Mainly suitable for full crowns, inlays and onlays.
In lab - the laboratory purchases a scanner, cutting machine and consumables. The dentist sends the patient's impressions and prescription to the lab. The lab scans models of the prepared teeth, designs the restoration and machines the restoration.
CAD/CAM methods
Centralised machining - in this situation the lab purchases or leases a scanner only. Again, the dentist sends the patient's impressions and prescription to the lab. The lab scans models of the prepared teeth and designs the coping and then sends this data off to an external machining centre. The machined coping is returned to the lab for veneerig.
Centralised scanners and machining - the laboratory sends the model away to the external centre to be scanned. The coping is also designed and machined at the external centre. The model and coping are sent back to the lab for veneering.
CAD/CAM methods
Non-contact sensor:
optical: laser point, laser stripe, white light, fotogrammetry
Contact sensor:
mechanical
Procera-Centralised machining
Stockholm/ Sweeden
Making a sectioned cast in the lab
Scanning the die and the cast CAD-data sent to central
machining center (checking) Milling starts in 19 minutes Copings (hand) packed and
mailed delivered within 5 days First patient 1985 (1994)
Katana-Centralised machining
Semmelweis Laboratory
• Scan-Measuring unit
• Engine-Milling and
grinding unit
• Therm-Sintering unit
• Elements-Materials
Everest-in lab
Software User interface
Light beam projection
15 projection
sequences
The rotary plate
moves on its vertical
and horizontal axis
during this process
CAD- Software
The preparation limit is automatically detected
Design
Decision guidance
Form of margins
Juncture region
Metal margin
Framework thickness
3-D virtual view of the occlusion on the screen The distances between occlusion and framework
construcion are shown with different colours. Easy, quick and safe design of frameworks in
connection with the virtual wax knife.
Virtual wax knife- Can be used to process the virtual framrwork in three dimensions on
the screen- Precise addition or removal of virtual material enables quick and
precise waxing
Design
Design
Cantilever bridge Bridge for veneering
CAM Engine 5-axis technology Ensures secure milling of
undercuts• The wide degree of
freedom during the milling process enables complex geometry
• Engine speed5.000 – 80.000 min-1
Engine
Simultaneously controlled 5-axis technology
Thin crown margins and best marginal fit
The wide degree of freedom during the milling process enables complex geometry
Engine speed
5.000 – 80.000 min-1
Cerec-in clinic
Intraoral scanning-no impression Digaital images of tooth and opposing arch
CAD and CAM
Milling the crown
20 minutes chairside
Thank You for Thank You for Your Attention!Your Attention!