Lec 1/26 Cad/Cam 1 Flashcards
Types of CAD/CAM deposition:
Fused deposition (fuse small particles in a large pile to make object), seletcive laser sintering method (build up selectively on only the object), stereolithography (object raises out of pool of monomers)
5 axis modeling can rotate how many degrees around hor?
30’ in either direction
Triad of fabrication for CAD/CAM
scanner, resto desing software, resto fabrication/ production
Man and year he 1st started CAD/CAM development:
Dr. Duret, ‘71
1st stage of CAD/CAM development:
optical impression of abutment tooth, then design optimal crown, mill crown using numerically controlled milling machine
Developer of CEREC:
Dr. Moermann
Adv of the CEREC system:
chairside, directly measure prep intraorally, designa nd carve inlay from a cermainblock, compact machine, same day restos
Function of scanner:
transforms geometry of receptor unit (tooth/implant) into digital data that can be processed by a computer
Types of scanners:
optical, mechanical
Which scanner types can be non-chairside:
both optical and mechanical
Which scanner types can be chairside:
optical only
What type of scanner is the Procera?
mechanical
Mechanical scanner technique:
contact probe w ruby ball, maps entire cast prep surface line by line
Adv of mechanical scanner:
precise but less accurate than newer optical scanning system
Disadv’s to mechanical scaner:
time, expense, less accurate than newer optical scanning systems
Smallest intraolral scanner:
3M True definition scanner LAVA
Largest intraoral scanner:
Trios
Optical technologies, contact or non-contact?
non-contact
5 Non-contact optical technologies:
confocal microscopy, triangulation, optical coherence tomography, active wavefront sampling, accordion Fringe Interferometry (we skip)
Benefit of combining imaging techniques:
min noise
Technique for obtaining high resolution optical images w depth selectivity:
confocal imaging
Imaging technique good for 3D imaging:
confocal
What is confocal imaging:
light represents one pixel in resulting image, laser scans object, image obtained pixel-by-pixel and line-by-line, brightness = relative intensity of detected light
Mirror used in confocal imaging:
dichroic
types of confocal imaging:
parallel and spot
confocal imaging system used by iTero system:
parallel, red laser light beam
Adv of iTero system:
no need to coat pts teeth, no coating powders (TiO2)
Disadv of iTero system:
color wheel to the acquisition unit itself resulting in a camera w a larger scanner head
Can the lab make a crown using a physical model?
yes
Can you make a conventional resto using chairside milling?
no
STL lsf:
stereolithography
Disadv of STL:
describes only the surface of a 3D object wo color or texture
Adv of iTero/ STL:
open platform, can be sent to any milling unit
STL can make:
crown, partial FDP, inlay, onlay, veneer, implant planning and surgical guide, invisalign
Benefits of Trios:
fast scan, blue light to provide surface registration, no coating powder (TiO2) before scanning,
TF? Trios can only scan in black and white
F.
Imagery type used by Trios:
confocal
Can you fabricate a physical model
yes
What type of technique is triangulation?
non-contact
The technique uses no radiation and is based on detecting reflected ambient radiation
passive triangulation
This technique uses light radiation, reflection to calculate position of target object:
active triangulation
Disadv of triangulation technique:
blind spot, if surface is invisible to both or either laser and camera
CEREC sf:
Chairside economical restoration of esthetic ceramics
Yr CEREC was inroduced:
1987
Latest model of CERAC:
CERACAC (‘09)
Ceram Bluecam is what type of scanner?
active triangulation
Cerac BlueCam:
active triangulation, needs uniform reflective surface and different materials reflect differently, this req need for powder on teeth, to make reflectivity the same, single images stitched together, single tooth or full quadrant
Can Cerac BlueCam do single tooth or full quadrant?
either
Cerac Bluecam can make these:
crown, inlay, only, veneer, interim partial FDP, prepcheck
Why do we always specify “single crown?”
check ask?
Adv of CEREC Omnicam:
continuous color image, no powder, single tooth, quadrant, or full arch
What can you design with CEREC Omnicam?
crown, inlay, onlay, veneer, partial FDP, precheck, implant resto
Disadv of CEREC:
closed platform, STL file can’t be sent to any milling unit but CEREC
OCT sf:
Optical Coherent Tomography
OCT:
light to capture um resolution, 3D from w/in optical scattering media (tissue), based on low-coherence interferometry, typically near IR light, xs of subsurface microstructure, splits broadband souce field into a reference files and a sample field.
What does the sample field do?
focuses through scanning optics and objective lens to some point below the surface of the tissue
What does the modified sample field do?
scattered back from tissue interface with Er, on te surface of the photo detection
AWS sf:
Active Wavefront Sampling
AWS:
single camera, AWS module, off axis apeture moves on a circular path aroudn optical axis, roduces rotation of object, object depth derived from radius of the sircular pattern points
COS sf:
Chairside oral scanner
Which is the “True Definition Scanner?”
Lava Chariside COS
Only scanner that uses video capture:
Lava Chairside Oral Scanner
Lava Chairside Oral Scanner, powder or no?
powder needed
WHat kind of light does Lava Chairside Oral Scanner require?
blue light
Lava Chairside Oral Scanner, open or closed platform?
open
Open platform means:
can be sent ot any milling unit for fabrication
Lava Chairside Oral Scanner can make:
crown, partial FPD, inlay, onlay veneer, implant restorations, ortho appliances
Lava Chairside Oral Scanner, how can they be made?
design or physical model
Considerations in making the resto to fit the prep in the CAD unit:
margin, connector, core thickness, cement gap
Function of CAM unit:
transform digital data to a product
subtractive technique involves:
soldi block milling
Additive technique involved:
3d printing
Type of milling machines for subtractive techniques:
3,4, or 5 axis
4 axis:
+ rotatable tension bridge
5 axis:
+ rotating milling spindle
Env for subtractive techniques:
dry or wet
when is dry milling done?
for pre-singtered zirconia to avoid absorption
when is wet milling done?
for metals, composite, silica based ceramics
Sintering method used for additive technique:
selective laser, fused deposition model, stereolithography
Work flow 1:
scan, design, manufacture chairside or Labside
Work flow 2:
Scan, physical model, fabricated conventional restoration fabricate labside CAM
Workflow 3:
conventional impression and working cast, scan and design,, fabricate labside CAM
I would review the slides again.
ok
