CAD/CAM CEREC course

CAD/CAM CEREC
Intermediate-level
Course
Dr. Christis Isseyegh
BDS [Hons. Lond.]

Objectives:
• This course aimed for dentists that have been using CEREC for at least 6 months to 1 year.
• Introduction to the Sirona Premium Package, Sirona OmnicamAC and Sirona MCXL Milling
Unit.
• Sirona Cerec Premium 4.4.3 Software.
• CAD/CAM Materials for chairside dentistry.
• Principles of scanning, desining, milling and glazing:
Inlays/Onlays.
Single Conventional Crowns.
Veneers.
Three-unit bridges [FPD].
Screw RetainedCrown on Implant.
Multilayer conventional Crowns, FPDs and screw retained crown.

Introduction to the Sirona Premium Package, Sirona
Omnicam AC and Sirona MCXL Milling Unit.

The Computer
• Overclocked gaming spec processor.
• Storage: 2-levels.
128GB SSD [Solid State Drive] storage where the windows operating system partition is.This is faster
and smaller than the hard-disc.
500GM Hard-disc storage.This is where all the patient’s data and scans are saved once we are finished
with them.This is considerably slower but bigger than the SSD.The more data you accumulate, the
slower it gets [Hence: Do not over-scan].
• Sometimes it crashes when we attempt full mouth reconstructions.This computer is ideal
for SEGMENTAL DENTISTRY so it is more advisable to attempt up to 3-unit crowns/bridges
for full mouth reconstructions.
• This computer is not state of the art any more so you can upgrade it but be sure to check
hardware compatibility with the software.
• Disable software updates to prevent compatibility issues.
• Licence dongle is inside. [*CEREC licence is quite expensive.]
• Always save “CTRL-S” at least after scanning, and after finishing your restoration design to
prevent losing data if the computer crashes.

The milling unit
• Swipe the top of the screen to check engine sounds. Leave the unit door open overnight.
• 50-75ml dentatec needed per water tank. Untighten with the driver but tighten by hand.
• You can mill a prosthesis of up to 9 units on large zirconia blocks and 5-6 on acrylic blocks.
• For large zirconia blocks you need to remove the inner sleeve mount in order to fit them in.
• You can now even grind fused cobalt chrome blocks which are then sintered [Speedfire
furnace] to reach compressive strengths of up to 1500MPa.
• For zirconia and for acrylic blocks [Telio], choose milling instead of grinding since it is faster
and better. Replace the burs [the “shaper” milling bur goes on the right side and the smaller
“finisher” bur goes on the left].
• Milling is preferable to grinding when available.This needs to be activated in the
configuration section once and then it will remain active.
• MCX5 can cut a full mouth bridge on discs but it may even take up to 12 hours, and about 40
minutes for a crown [works with a single bur-axis]. Not ideal for chairside dentistry.

Furnaces
• IvoclarVivadent’s Programat for vacuum sintering of ceramic materials. It is
an excellent furnace but it does not communicate with cerec hence the
sintering time is universal and not mass dependent.
• Sirona’s SPEEDFIRE: New furnace which can sinter up to 3 unit bridges
including cobalt chrome and zirconia. It communicates with CEREC and
sometimes when the mass is small it can sinter zirconia blocks in a few
minutes [They normally take hours].
• Ivoclar’s quickfix putty/liquid is only for emax as it is needed to transfer the
heat into the material. It is not needed for empress. Also do not use it for
suprenity as it will cause fracture.

The Omnicam
• It is not a camera, it’s a scanner that takes 20 photographs per minute.
• It needs to be calibrated every few weeks using the calibration tube.
• It has the advantage of being slim-line and hence it is able to scan even at the
tightest of areas e.g. third molars.This is a big advantage over other brands which
are bulky, heavy and thick.
• It’s main disadvantage is that it cannot distinguish perfectly between hard and soft
tissue and sometimes even saliva.
• Remember to leave it on the heater to avoid fogging of the glass.
• The strength of the heater can be easily adjusted in the configuration settings.
• Scanning with powder takes considerably less time and it’s easier.
• Metallic surfaces need to be sprayed with powder prior to scanning.
• Change music/ adjust volume and calibrate in the omnicam in the configuration
settings section.

Exporting capabilities
• Scans can be exported as .stl files and sent to compatible laboratories.
• Also using Sirona’s Cerec connect you can send your scans to the lab along
with a laboratory prescription and they can manufacture your restoration on
their InLab e.g. full arch zirconia frameworks etc…You can even open a live
chat with your technician using the chat option at the top right corner.
• Cerec scans .stl can be combined with 3D radiographic imaging scans [e.g.
Galileo] and merged using external software [SIDEXIS] to design surgical
stents for guided surgery that can be 3D printed in-house, in a lab or sent
abroad [stereolithography].

Commonly used CAD/CAM Materials for chairside
dentistry.
Several more materials exist and there’s an individual brochure for each available online for
free.

Chairside Materials [part 1]
• CEREC Blocks:
 Feldspathic porcelain with a flexural strength of 154Mpa.Weakest of all materials, and most difficult for the
machine to cut since they are crystallised. Single colour, polychromatic and multilayer blocks exist.
• Leucite-reinforced glass ceramics:
 Ivoclar Empress CAD with a flexural strength of 160Mpa for single tooth restorations. High and low
translucency as well as polychromatic blocks exist.
• Lithium Disalicylate:
 Ivoclar E-MAX. In March 2017 ivoclar announced an average biaxial flexural strength of 500Mpa. These are
only 25% pre-sintered at a much lower flexural strength of but enough to be tried in prior to crystallising!
• Zirconia-Reinforced Lithium Silicate:
 Celtra-duo [Dentsply]:This are something between E-MAX and Suprinity at a compressive strength of
370Mpa. This has amazing aesthetics, does not require glazing [polychromatic blocks] and only needs 11
minutes in the furnace.
 Vita Suprinity: Claim to have a flexural strength of 420Mpa.
• To avoid the need for staining, polychromatic blocks should be used that can be just glazed and
sintered, or even sintered without glaze at all.

• Zirconium Oxide: Grinding and MILLING
Kuraray Katana: 600MPa flexural strength for the UTML [ultra translucent multi-layer]
which is highly aesthetic with translucency gradation within the block.
Less translucent CAD blocks with 1200Mpa flexural strength exist but can lead to a higher
rate of root fractures.
• Cobalt Chrome:
These are blocks of pre-ground metal that has been lightly fused together into blocks to be
cut easily and is then sintered to reach a compressive strength of 1500Mpa.
• Hybrid Materials:
These materials can be cut PERFECTLY and feel great in the mouth. Patient’s love them.
Ideal for inlays, but it’s a good idea to avoid heavy contacts.
Vita ENAMIC is a very trustworthy material at the moment. Cerasmart and 3M’s Lava
ultimate also exist but some increased rate of de-bonding has been reported.

Chairside Materials [Part 3]
• CAD-on multilayer crown [Ivoclar vivadent system]:
CAD-on involves zirconia coping with emax veneer.
The zirconia coping is bonded to the emax veneer by fusion.
The fusion cement is called CRYSTALL/CONNECT by ivoclar and is a powder that is vibrated
into a paste using IVOMIX.
The paste is then placed in the EMAX crown and the zirconia coping is pressed in it.
The restoration is then vibrated [IVOMIX] again ensure full seating and removal of excess
cement.
The bonded restoration is then fired in the programat furnace under the option “CAD-on
Fusion/Crystal”.
The materials fuse perfectly and the connection is invisible.
If the zirconia coping is made more than 0.5mm thick, then it can completely hide a
darkened tooth or a supra-gingival ti-base that would show through an all ceramic
restoration.

• Additional information on zirconia:
Chose milling instead of grinding.
For bridge frameworks the connector are must be 9mm2 and no less. [InLab can also
show us finite element analysis].
In monolithic zirconia crowns, 0.3mm occlusal thickness is enough [can just fit the
probe in between the prep and the opposing tooth in ICP].
In the “design” stage you can reduce the thickness of monolithic zirconia crowns and
allow space for EMAX veneering [CAD-on] or lab-made feldspathic porcelain addition.
Do not polish and overheat zirconia or it will go brown. Adjust it using the “magic
touch” bur.
If the speedfire oven is not available, mill the block in-house and send it to the lab to be
sintered. An average 21% shrinkage occurs post sintering. However this is very
accurately compensated by CEREC.

Principles of scanning, designing, milling, glazing
and bonding
ADMINISTRATION

Administration Section [part 1]
• 95% of the times we use the biogeneric individual option.This comes from a
database of over 4000 digitalised teeth.
• Other options include a copy, where the tooth to be prepared is in a good
condition and is scanned before the preparation to be replicated.
• Biogeneric reference allows us to use a tooth in the contralateral side of the
arch in order to copy all or preferably part-of its shape.
• A multilayer option can also be selected where the abutment tooth [coping]
can be made of zirconia or emax and the veneer layer can be made of emax.
Zirconia coping [Sirona] fused with E-max crown [CAD-on].
When both an emax coping and veneer is used, make sure that the coping is made of
medium opacity emax and is crystallised at the correct furnace program.Then the
crown is made of low or medium translucency and is crystallised at a different program
than the coping.

• Sirona has developed two ways of scanning implants:The scan-body over a ti-base
or over a scan-post.
• A scan post is longer than the ti-base allowing us to see clearly the complete
seating of the scan-body in order to prevent height discrepancies.
• In a ti-base the only way to confirm this is by taking a radiograph.
• Scan-posts emerge over the gingival area and allow for easier scanning of the scan-
body.
• However the metallic base of the scan-post needs to be sprayed with powder prior
to scanning as it is reflective.
• Which-ever of these 2 methods are used, make sure that the correct option is
selected in the administration section otherwise there will be a severe
miscalculation of the implant’s vertical orientation in the bone.
• Make that the correct ti-base is selected for the correct implant system in order to
have a correct anti-rotational [hex] orientation. E.g. ZTSV is for zimmer implants
and is also compatible with Zimmer, BioHorizons and A’B implants.

• For a bridge [FPD]:
Mark the abutment teeth for the crowns first [retainers].Then mark the pontics.
If a monolithic zirconia or acrylic crown is made, then click on the connectors and change
them from tube-shaped to butt-joint.
If the bridge will be multilayer/split [all of it or some of the teeth], then these need to be
selected in the next section.The connectors need to be adjusted accordingly.Veneered
portions need two connectors, one for the framework [tube] and one for the veneer [butt],
whereas monolithic portions require single butt joint connectors.
• Multi-layered screw retained crown:
In angulated anterior implants where the abutment screw emerges buccally, this is
essential.
Our strongest option for the abutment material is zirconia [Sirona inCoris ZI meso].
For the veneering material,Vita ENAMIC hybrid is available as well as EMAX which we can
use with the CAD-on technique.

Ti-base vs Scan-Post
On the scan post [Top right],
notice the line extending below
the lower margin of the
scan-body which
is to ensure correct scan-body
orientation.

Principles of scanning, designing, milling and
glazing
SCANNING

Scanning [part 1]
• Research in Zurich to find the most efficient Method for intra-oral scanning.
• There is an algorithm that is responsible for “stiching” the images together.This
algorithm works better when a particular discipline is used when scanning.
• Scanning is still quicker when powder is used. Powder is still essential for highly
reflective surfaces [e.g. scan-post or ti-base, amalgam, implant crest module,
metallic crowns, fixed orthodontic appliances].
• Always polish your preparation to remove any sharp spots prior to scanning.
• 4-hand dentistry is essential. Let your assistant retract and use suction.
• Use an optra-gate or other lip retractor.
• Use dry guards to absorb saliva. A dry environment is always essential.
• Always look at the video while scanning, never in the mouth!!

Scanning [part 2]
• Select the catalogs which are needed in the scanning section.
• In order to undo a failed scan, place the cursor on the catalogue and right-click.This
will undo you last scan.
• If you scan in the wrong catalogue, open any new random catalogue to use it as a
drop off in order to put your scans in their correct catalogue.
• For implant scanning, scan the gingival-mask first and include the whole sextant.
Copy that sextant in the corresponding jaw catalogue and using the cut tool
remove the implant area. Place the scan-post or ti-base with the scan-body and
then only scan that area!This saves time and avoids over-scanning.
• For the buccal occlusion scan just scan a figure of 8 and include the gingival
outline.
• Scanning should not take more than a maximum of 2 minutes per jaw. If it does,
delete your scan and repeat.

Scanning discipline [part 1]
• 1: Start at 45˚ lingually to the premolars and
scan all the way posteriorly.
• 2:Tilt the omnicam to 90˚ lingually and scan all
the way anteriorly.
• 3: At the premolars come up to the occlusal
table and scan towards the posteriors.
• 4:Tilt the omnicam 45˚ buccally and scan
towards the anteriors.
• 5:Tilt the omnicam 90˚ buccally and scan
towards the posteriors.

Scanning Discipline [part 2]
• Finally move the omnicam directly over the
prepared tooth or implant.
• Tilt the camera 15 degrees mesially and distally
to record the proximal surfaces.
• Rotate the camera buccally and lingually to
finalise the scan of the preparation.
• For implants:
 Apply spray on the metallic surfaces if a scan-post
is being used.
 The cervical tunnel of the scan body must be
completely scanned all around as well as the
pyramidal shape on the top.

glazing
“MODEL” SECTION

Edit Model
• At this stage ensure that the occlusion is correct and also ensure that the
software has been able to place the casts in correct occlusion. [You can mark
this using articulating paper to compare them].
• At this stage you can also remove/extract a tooth from the model in order to
be able to design a an immediate replacement bridge. In order to do this
you need to use the “specify area” tool and then use “reduce” to cut away
the tooth.

Model Axis
• This step allows the software to compute the Sphere of Monson. It’s a very
important step and it has to be done correctly every time, otherwise we are going
to end up with inconsistent proposals.These need to be adjusted in the following
order:
i. Saggital horizontal line:
This line takes into consideration the curve of Spee [Antero-posterior occlusal line] and the
Camper’s line [Ala-tragus line]. Both inclination and vertical height are set using this line.
This is much easier with the lower jaw.The line has to touch the mesio-buccal cusp of the
first molar and the tip of the canine.
When done on the upper jaw, the line must only touch the tip of the canine, hence it is much
more inaccurate as the inclination cannot be visualised.
ii. Tray-orientation:
Align the scan with the midline and make sure that all the model is in the tray and follows its
curve.
iii. Transverse horizontal line:
Just make sure that this is approximately parallel to the horizontal plane in the transverse
direction. Do not use this line to adjust the vertical height.This corresponds to the curve of
Wilson.

Camper’s line and Curve of Spee

Curve ofWilson and Sphere of Monson

Jaw Line
• This line tells the software where to place the tooth in its proposal.
• It is very important and if it’s not well adjusted, we end up with incorrect proposals.
• It’s especially important for implants that are too buccally inclined.The jaw line will
tell the software the position where the tooth should be calculated.
• First put he number in the middle of the tooth.
• The most anterior point is between the incisal edge of the central incisors.
• The second point is set on the distal aspect of the canine [lingualy towards the
cingulum].
• The third point is set distal to the second premolar.
• The last point is set at the distal of the last tooth in the scan.

Draw Margin
• This is another important step that can lead to inconsistent proposals.
• For a crown, we need to move from the inside of the preparation towards
the margin as the algorithm gets confused when we are approaching the
margin from the gingiva.
• For inlays, the automatic settings works very well by making two clicks on
the lingual and then buccal margin of the preparation.
• Disable the model-box from the view section of the tools and turn the scan
upside down in order to confirm or double-check an “un-clear” part of the
margin.

Edit base line
• This is only available for implants.
• It corresponds to the “height of contour” of the natural tooth.
• It has a different shape according to the tooth that we are replacing.
For incisors the shape is triangular with the triangle’s base facing buccally and the apex
facing lingually.
For the canine the shape is between triangular and ovoid.
For the premolars the shape is ovoid.
For the lower molars the shape is rectangular to trapezoid.
For the upper molars the shape is trapezoid to rhomboid.

Insertion axis
• Using this we can direct the path of insertion undercuts and try to eliminate
undercuts.
• An undercut may be present and it will automatically be blocked with virtual wax
[select this option in the parameter’s section]. However we need to ensure that
there are no undercuts reaching the preparation’s margin otherwise we will end-up
with open margin restorations which need to be repeated.
• In order to set this line, we move the scan to a point where we can see all the
margin line, we also try to compensate for our undercuts, and then in the tools we
click “set insertion axis”.
• This can also be done using the arrow tool, however the method described above is
easier.
• If we have more than one restorations and we want them to be parallel, then we
can select them all [clone] using CTRL+A or de-select them using escape “ESC”.
• For implants the axis has colours to help us with the orientation. Parallel is white,
semi-parallel is yellow and then red is incompatible. Make sure it is at least yellow.

Incisal pin [In the articulator tool]
• If we have a wear case, or for any other reason would like to place our
restoration at a higher occlusal vertical dimension, then we can use the
incisal pin in the articulator tab.
• Choose how much to open the pin.
• It is a good idea to carry out facial measurements of resting and occlusal
face height prior to attempting this and also to check if the patient can
tolerate an increase in OVD using splints.

Trimming the model
• This part is not important for crowns or inlays/onlays. It is only important for
implants.
• It is normally done automatically.
• If it’s not satisfactorily done, then use the tool to cut around the implant.
• If several restorations are made at the same time, make sure that the
correct tooth/implant is selected prior to trimming.This is a common error.

Identifying the scan-body head
• Once the scan body head is clicked and confirmed the software will
compute the implant body orientation.
• If a scan-post has been used under the scan-body it will be changed into a ti-
base from this stage onwards.

Copy Line
• This option only appears when we have selected the “biogeneric reference”
in the administration section where we are going to use a tooth in the
contralateral arch as a shape-reference for our restoration.
• This is commonly the case when we are restoring one of the central incisors.
• In this section, it is preferable to select only the upper [incisal] third of the
tooth to be copied.
• Avoid copying the whole tooth because it will force it in certain areas,
leading to insufficient or excess thickness.
• It is better to merge the copy with the proposal instead.

Digital Smile Design
• Used when anterior reconstruction is planned.
• A useful tool to assess incisor angulation, lip-support, crown heights, smile line,
occlusal vertical dimension [OVD], compare lower with upper anterior face height
and to assess gingival show and plan soft tissue modifications.
• Also a great selling point to address the patient’s aesthetic concerns.
• First take a portrait picture of the patient SMILING and include the eyes and the
ears. Import this picture in the computer.
• Measure the horizontal distance in mm between the outer canthus of the eyes.
• Full-arch scan of both arches is then needed.
• In the smile design section, place the points as shown in the diagram.
• A 3D model of the patient’s face is created and can be moved around and assessed.

glazing
“DESIGN” SECTION

Design - PARAMETERS [part 1]
• These are very important!!
• Once you learn your “style”, then go to configuration -> parameters and set your
own standard pre-sets for certain restoration types.
• Radial Spacer:This is good at 120. Less than 80 becomes very difficult to seat and
should only be attempted for veneers.
• Occlusal spacer:This is ok at 120. However if you have limited space in occlusion
and need material thickness you can reduce it to 100, or even 80 sometimes.
• Occlusal Milling Offset:This does not affect the restoration significantly. It is there
only to compensate for bur bending or wear. If you want to get more out of a worn
down bur, then go with a negative OMO. However a zero setting is the best here.
• Proximal contact strength: [Varies on different milling machines]
25μm between a crown and a natural tooth.
2 crowns next to each other should be 0μm in one and 25μm in the other [they add up].
For 3 adjacent implants, because there is no periodontal ligament, the middle implant must
always be 0μm and the ones next to it 25μm.

• Occlusal Contacts:
These need to be at least one colour lighter than the adjacent teeth.
Usually works well on zero or negative values.
• Dynamic Contacts:
Always zero except if we are restoring a canine [Canine guidance in mutually protective
occlusion, for posterior tooth disclusion in lateral excursions].
• Radial MinimalThickness [Normally Locked]:
Reduce it up to 800 [0.8mm].We don’t really need 1.5mm radial thickness.
• Occlusal MinimalThickness [Also Locked]:
Set as adviced per material.
Depends on patient force factors.
• Margin Spacer and Margin Ramp Angle:
Do not touch these two parameters, margins always work well with the factory settings.

• These are specific for implant retained crowns:
Gingival pressure:This is of importance mainly in anterior teeth if we have created an
emergence profile [individualisation]. In such cases use 200 gingival pressure to avoid
pocket formation.
Gingival depth:This defines the depth at which the height where the connection between
the abutment and the veneer is. For monolithic restorations it does not make a difference.
Place it level with the gingiva for monolithic restorations and more sub-gingival in aesthetic
multilayer restorations.
• These are specific for bridge design:
The shape of the base of the pontic can be adjusted.This can range from total ridge lap, to
modified ridge lap, and then to ovate [to create an ovate shape go for total ridge lap design
here and fill it up later in the design section].
Ovate pontics also reduce food packing and are easier to clean.Total ridge lap designs may
have superior aesthetics but are the worst in terms of hygiene.

Design-Morphology and Positioning
• In this section we can choose whether we want to use the option of the biogeneric
individual or if we would like to choose a certain type of tooth morphology from
the tooth database DB.
• There is a huge number of teeth in the tooth DB to chose from.
• The Candulor Bonatric option that offers a narrow occlusal table and smooth cusps
in posterior teeth and is therefore useful in reducing the force exerted on implants,
especially for immediate loading.
• In positioning, first check to see whether harmonic positioning does the job.Then if
needed move the tooth in all directions to position it and then use the scale tool to
resize it.
• Do not worry about the contacts at this stage, these can be dealt with later very
easily.
• For a bridge we can right click to find the tools that allow us to alter the shape of
the pontic’s base.

Design - Edit Restoration [part 1]
• Firstly go to “view” tools and enable cursor details.
• CTRL + M is a shortcut to add and remove the minimal thickness. Make sure that is on.
• CTRL + G is a shortcut that adds a grid to check symmetry.This is especially useful in
anterior teeth orientation.
• Enter the articulator section and accept the pre-set configuration [In order custom-set the
articulator, a face-bow registration is needed]. Once configured, this allows us to see the
contacts at ICP [CO] and lateral and protrusive movements using the occlusal compass tool.
We can even move the jaw left to right.
• Start adjusting the proposed restoration by first fine-tuning the positioning and then scale.
• Adjust your crown thickness to the proposed minimal thickness using the circular tool in the
“shape” section.To adjust the size of the tool, press the right click and drag the cursor up or
down as required.
• Avoid using “Add” and “Remove” for large modifications as it will create bubbles and pits.
Instead, over-contour using the circular tool and then smooth.
• Using the “Reduce” tool, you can select an area and then chose how much to reduce it.This
allows us to create space for veneering a less aesthetic material with ceramics.

• Splitting [Multilayer] restorations:
This only works when the multi-layer crown/bridge has been already selected in the
administrator section.
These are particularly useful in angulated implants [where the abutment screw
emerges buccally], or when we are using a stronger core material and want to veneer it
on top with a more aesthetic ceramic option.
Once the split has been performed, the abutment is designed. Adjust the split line
[place it more coronal palatally and more apical buccally to aid cementation without
compromising aesthetics]. Use the scale tool to scale the whole abutment or just an
area. Retentive grooves can then be added, but are not really needed.The abutment
should be made as small as possible to allow space for the veneer.
Then design the crown on top. Most of the time, space is quite restricted in multilayer
restorations and is the main challenge.
In multilayer [Split] bridges, notice how there is a different connector design in the
framework and a different design in the veneering materials.

• Occlusal Contacts:
Firstly go to the shaping tools -> contacts and click all of them to have them adjusted
to the pre-selected parameters.This works better for posterior teeth.
Then ensure that there are no contacts on the non-functional cusps as this affects the
cross-tooth balance and leads to non-functional cusp fractures. Especially lingual cusps
on lower molars.
You can add a purple “bite registration” material in the articulator section that will
enable you to see the contacts and remove them accurately.
Use the occlusal compass to ensure that there are no dynamic contacts on the
restoration and remove them with a smooth tool.
Use the articulator tools to move the jaw left to right and check lateral and protrusive
movements.
• Proximal Contacts:
These should always be the last thing to check before proceeding to production.

Troubleshooting:
• When “needles and swords” start appearing on the restoration and cannot be
removed, this is probably because a major penetration [heavy contact area] is
present and has caused the software to crash.
• In such a case, our only option is to return to the “model” section without saving
our work.
• If the above does not work, then we should go back to the scanning catalogues,
make a small “cut” to reset the rendering process and proceed from there onwards
in order to force the software to re-calculate the whole case.
• If even this does not work, then we need to restart the computer.

glazing
PRODUCTION [MILLING and GRINDING] .

Production:
• The computer automatically selects the smaller block needed for the restoration
and places the sprue as such to minimize the time needed for production. Any
changes to these and the production time will be increased.
• In a screw retained crown we cannot change anything at this stage since the
orientation of the notch at the base of the ti-base limits such changes.
• Move the restoration within polychromatic blocks to achieve the desired shade.
• Add the corresponding jaw in the view options, turn it upside down and check that
there are no “white spots” between the restoration and the preparation, except at
the margin.These show us where the restoration is physically coming in contact
with the underlying prep. If it does come in contact in areas other than the margin
then polish the prep, or add spacer height in the parameters.
• Extra fine burs are excellent.These are finishing burs that add more time to the
production but have an excellent outcome.
• For acrylic and zirconia blocks it is preferable to choose the milling option.

Production:
Troubleshooting:
• If the milling device does not appear available then:
[Hover the cursor over the milling device tag and read the pop-up message. It usually tells
us what the problem is].
Attempt to poll it in the configuration section.
Ensure that the milling unit is not engaged with a previous restoration window that is
minimised.
Ensure that the correct burs that are needed for the restoration are in place.
Sometimes we need to reset the IP address which is shown on the milling unit’s screen.

glazing
GLAZING AND SINTERING .

After production/milling
• Remove the sprue as needed per material [Use water cooling as needed per
material]. Use gloves at all times to avoid contaminating the restoration.
• Use the steamer to de-grease the restoration after milling.This is very important
both for bonding and for glazing.
• You can leave restorations un-glazed when using polychromatic blocks. In contrary
to common belief, research has shown that unglazed ceramic restorations are less
abrasive to the occluding tooth.
• If glazing is required:
Avoid glazing proximal contacts or they will become too strong.
Use endodontic files to place the mahogany stain in the fissures.
• Sintering using the appropriate furnace program. Remember, object-fix putty is
only needed for E-max and must be avoided for vita-suprinity as it causes fractures.
• After sintering, a steamer should be used again to clean the crown again prior to
etching and bonding.

Same day before and after [Cerec block inlays].

CAD/CAM CEREC course

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