lecture 8- intro to digital dentistry, scanning Flashcards
The use of computer programs to create
two- or three-dimensional (2D or 3D)
graphical representations of physical objects
CAD: computer aided Design
The use of computer software to control machine tools and related machinery in the
manufacturing of work pieces
CAM: computer Aided Manufacturing/milling
➢Point Cloud Meshing?
collection of data points called point cloud is used to depict a real world object
combine multiple scans to create complete model
CAD/CAM is often saved and stored as
.stl file (standard triangulation language)
CAD/CAM is a file format which is an openly documented format for
describing the surface of an object as a __________,
that is, as a representation of a 3-dimensional surface in
triangular facets
triangular mesh
What do we need to apply this concept to practice?
- intra oral scanner
- designing software
- production Unit
-additive: 3D printing
-subtractive: milling
Some available systems for CAD/CAM?
- CEREC Primescan, Omnicam or
Bluecam (Sirona) - Tiors, 3 Shape (3D Biocad)
- iTero digital scanner
- E4D Dentist
- Medit
- Lava COS
Requirements of intra oralscanner
- Easy to use
- Accuracy
- Software capability and speed
- Cost
It is the use of additive manufacturing to create dental
prostheses such as aligners and dentures
3D printing
Designed to cut crowns, bridges, copings, frameworks,
implant abutments and more from materials such as
ceramics, zirconia, alloys, resins or wax
milling machine
Characteristics of CEREC system
- Inlays/ Onlays, Crowns, & bridges
- Visible Blue Light (LEDs)
- Powder is required for some
scanners - Digital on-screen articulation
advantages of
1. CEREC omnicam
2. CEREC bluecam
- CEREC omnicam:
-powder free
-precise 3D image in natural color
-8-12 min - CEREC bluecam
-high precision
-rapid scan in powder coated surfaces
-easy to use
What can we do with CAD/CAM?
- Single tooth restorations on natural teeth:
* Crowns
* Implant restorations
* Inlays
* Onlays
* Veneers - Multi-unit restorations on natural teeth
* 3-unit bridges - Implant restorations
* Implant planning & surgical guide
* Custom abutments
* Cement retained and screw retained crowns
* Titanium milled bars for full arch restorations
* Frameworks for implant bridges
* Full arch monolithic FDP - Removable prostheses
* RPD Frameworks
* Complete Dentures
Why use CAD/CAM?
- Faster turn around for fixed restorations
- Can delegate scanning to Auxillary team members
- Patients believe high tech is better
- Possible to have less human error in production process
The multilevel quality
improvement afforded
through digital
technology is recognized
in
workflow and
efficiency, record
keeping, and data safety
CAD/CAM Classification based on:
1
2
3
- data Acquisition
- Accessibility to STL Files
- Production of final restoration
Data Acquisition:
- Direct
- Indirect
Accessibility to STL Files:
- Open system
- Closed system
Production of final restoration:
- Chair-side Production
- Laboratory Production
- Centralized Production
Centers
The data is directly obtained from the patient’s mouth via intra
oralscanner
data acquisition (direct)
The data isindirectly obtained in the lab either from an
impression or a stone cast via bench scanner
indirect (data acquisition)
Are not dependent on the manufacturer, can be used with
any software to fabricate the final restoration
open files
The data is controlled and manipulated bythe owner
(manufacturer)
closed files
Production of final restoration:
- Chair-side Production: No provisionalization is needed
- Laboratory Production: dental laboratory scanner and designing software ->CAD/CAM
- Centralized Production: production center -> CAM
Workflow Between Lab and
Practice
digital workflow
Digital technologies improve the
workflow from diagnosis,
planning, and treatment
-Intraoral scanning is faster and
substantially more comfortable
-Intraoral scanners can increase
productivity, and efficiency
digital workflow
digital workflow steps
- first appt scan
- file sent to lab
- design restoration
- fabricate restoration
- finish
- receive from lab
- second appointment seat crown
Conventional Vs digital workflow initial cost
analogue(conventional)
initial cost: VPS, registration materials ~$50
digital initial cost:
scanner $20k-$30k
milling unit $110k-$120K
Conventional Vs digital workflow additional cost:
analogue: trays, dispensers, and stone, lab cost, shipping
digital: electronic lab prescriptions, blocks, burs, and maintenance, lost time and production if machine goes down
Conventional Vs digital workflow time
analogue/conventional:
- Tray selection or Custom tray
- Setting time
- Remake
- Opposing arch
- Inter-occlusal records
- Disinfection
- Shipping time
- Disinfection
- Pourthe impressions
or scan impressions - Setting time of stone
- Mountthe casts
- Ditch the dies
- Scan dies
- Wax-up and/or
fabrication - Shipping
- Restoration Delivery
Conventional Vs digital workflow time digital:
- Learning curve
- Scan (prep, opposing & buccal)
- Evaluate the scan
- Rescan
- Lab prescription
- Received (Electronically)
- Design
- Scan cast/mill/print model
- Restoration milled
- Shipping
- Restoration delivery
Conventional Vs digital workflow
Tissue Displacement:
- MUST for both
- dry field is a MUST for both workflows
- 0.5mm of uncut tooth structure apical to the finish line is required
are still recommended for full-arch
restorations
conventional impressions
was observed regarding the marginal gap
of single-unit ceramic restorations obtained from digital or
conventional impression techniques
no significant difference
Some advantages of the Optical/Digital technique:
- more comfortable to the patient
- equal marginal fit (both clinically accepted)
- improves dentist/lab communication
- cuts down the turn around time
for full-arch impressions
- use conventional impression
- digital impression are not as accurate across an arch
Posterior single tooth restorations fabricated from
intraoral scans by using CAD/CAM technology
have acceptable results for
shade, contour,
marginal adaptation and occlusion
survival rates
- 88.7 % up to 17 years of clinical service (Otto et al.
2008) - 88.8% in 5.5 years vs 93.3% for gold (Ferdelin, 2010)
- 97% in 5 years 90% in 10 years (Fasbinder, 2006)
- 98.4% in 9 years (Posselt 2003)
when prepping crowns reduce an additional ____of ____ and ___ tooth surfaces compared to standard prep for increased strength
0.25-0.5mm
of facial and occlusal
