Digital Technologies Part 2 Flashcards
most chairside milling machines are:
4 axis mill
most laboratory milling machines are:
5 axis mill
describe the 4 axis mill
- burs move in 3 axes X,Y and Z
- material/block rotates in 1 additional axis (3+1 milling machine)
- the addition of the 4th axis (A axis) allows the block to automatically rotate 180 degrees so that it can mill intricate details
describe the 5 axis mill
- the milling block is rotated in additional axes
- can mill complex designs such as implant superstructures, RPD frameworks, complete dentures
- the milling block is rotated in additional axes
- can mill more complex designs such as implant superstructures, RPD frameworks, dentures
what is the difference in speed between the 4 axis mill and the 5 axis mill
- 4 axis mill faster in single restorations
- 5 axis mill faster in multiple restorations
what is the difference in block size between the 4 axis mill and the 5 axis mill
- 4 axis mill: max 80 x 16mm
- 5 axis mill: 98.5 x 30 mm
what is the difference in undercuts between the 4 axis mill and the 5 axis mill
4 axis mill: disabled
- 5 axis mill: limited
what is the difference in indications between the 4 axis mill and the 5 axis mill
- 4 axis mill: crown and short FPD
- 5 axis mill: long FPD and dentures
accuracy and resolution is _____ related to the number of axes
not
what materials are used in a wet mill
-lidisilicate
- feldspathic porcelain
- Co-Cr metal
what materials are used in dry mill
- resins
- Zr
what materials are used in dry and wet mills
- Zr
- some metals such as titanium
- resins
the liquid in a wet mill is:
a combination of distilled H2O and another liquid (manufacturer specific)
describe the maintenance on dry and wet milling
- still required with a dry mill
- dry and wet mills can vary in the level of maintenance required and level of noise during operations
describe the functional movement of the bur
- bur movement is related to the tooth preparation
- successful tooth preparation is required for successfully milling
- bur dimensions influence the milling outcome
the margin of the restoration should be at least ____ of the width of the bur tip
1/2
cusp/fossa has to be at least as wide as:
the diameter of the bur
tooth preparation cannot exceed the height of:
the bur
margin thickness depends on:
bur size and crown material
what is the pre acquisition checklist
- administration tab complete
- correct material selected
-patient evaluation - scanning armamentarium
-optragate or isovac placed
-proper isolation
what is done in patient evaluation for cadcam
- maximum opening
- tongue size
- cheek elasticity
- buccal fat pad
- third molars
what is the scanning armamentarium
- isovac or optragate
- 4x4 guaze
- cotton rolls
- mirror
- forceps
what is the depth of field for scanners
0-16mm
what are the golden rules of scanning
- always start on an area that the scanner knows and then slowly blending in the new area
- if it ever freezes or loses its place stop and remove the scanner and reposition to a known location
what are the prepped quadrant scanning steps
- occlusal
- buccal
- lingual
- distal interproximal
- mesial interproximal
- corrective scans
what is done in the scan evaluation
- examining for missing areas in the scan
- we need to capture the complete prep and adjacent interproximals
- fix each missing area individually with a short scan
- repeat for each missing area
- be careful not to make the scan file too large
what is the opposing quadrant scanning steps
- occlusal
- buccal
- lingual
- corrective scans
if you cannot get it to begin a scan or recognize teeth you can use ____ to help the scanner pick it up
optispray
what are the design steps
- define margin
- design morphology
- ensure the restoration fits the arch
how do you define the margin
use the double click to enter editing mode and then draw in the areas you want to replace then double left click to reconnect it to the margin
how do you change the moprhology
add, smooth, subtract
what color do you want for contacts
- we want to have light blue for the interproximal contacts and occlusal
for zirconia what should the contacts be
add a little green at the occlusal portion of the interproximal contact
what are the milling steps
- milling the crown here in 250
- firing or sintering
- glazing
what are the milling steps
- fill our the cerec block form and get the block from mary jane
- enter the barcode here and hit start
what are the cerec MC XL zirconia burs
- finisher 10
- shaper 25 RZ
what are the cerec MC XL lithium disilicat eburs
- step bur 20
- cylinder pointe bur 20S
what are the steps after milling for zirconia
- find which of the speedfire units the job got sent to, select it, then “pre drying and sintering”
- place the crown intaglio side up and start it (add 15 mintues to cool) dont touch when the temperature on the screen is over 250
- take the crown to chris to glaze
what are the steps after milling for emax
- take the crown up to chris to fire and glaze
- do not use the speedfires here in 250
