CAD/CAM

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Results
CAD/CAM components
CAD/CAM systems are compound of three basic functional components (7):
1. Data capture or scanning to obtain the oral information. To conduct this process there are different trading
systems:
– Intraoral capture. This method uses 3D optical systems for capturing single components anatomy. Some
examples are: Interférométrie Moire, laser scan, colorcoding (such as CEREC (8) and Evolution 4D (Evolution 4D)) (9).
– Anatomical dental duplicate capture (plaster cast),
usually using a laser scan method. Comercial products
such as RapidForm® (RapidForm), Slim® (Slim), polyWorks® (polyWorks) and Geometric Studio® (Geometric Studio) are used for the 3D meshes post-process.
2. CAD for the geometric design of the restoration.
These CAD systems have some simple functions to
change the restauration geometry.
3. CAM to manufacture the restoration. CAM systems
use computer-assisted information to shape a physical
object, using subtract methods (that removes material
from a starting block to obtain the desired shape) or using additive methods, used in the rapid prototyping, increasingly used in CAD/CAM oral technology.
Prosthetic abutments
Ideally, the abutment head should resemble a prepared
tooth with good form, morphology and emergence profile.
Proper implant positioning and appropiate preparation of
hard and soft tissue are critical to creating optimal emergence profile, function, esthetics, and periodontal health.
The types available can be separated into three categories:
Stock (prefabricated). They are milled in different materials (titanium, zirconium) using CAD/CAM technology. These are available either straight or preangled.
UCLA (laboratory wax and cast). They are manufactured from a gold platform and a castable sleeve that
allows to individualize the shape and height.
Computer-milled solid abutment (10). A solid block of
titanium is milled using a computerized milling machine to the operator´s specifications.
CAD/CAM abutments in Implant Dentistry
Advantages of CAD/CAM abutments
Custom abutments created with CAD/CAM technology have the potential to provide the advantages of both
stock and laboratory processed custom abutments without the disadvantages(2). First, like laboratory-made
abutments, CAD/CAM abutments are specific for each
patient (11), however the results are much more consistent. The technician´s learning curve is less steep than
that for handmade components. The technician controls
the abutment design using CAD software that incorporates parameters to assist him or her. The virtually designed abutment is electronically transferred to a CAM
milling apparatus that creates the abutment from a block
of the selected abutment material. Most of the inherent
dimensional inaccuracies of waxing, investing and casting are eliminated. Unlike stock or cast custom abutments, the abutment surfaces of CAD/CAM abutments
are not subjected to the above-mentioned manipulation
processes after machining, so CAD/CAM abutments
have the potential to provide the most accurate fit of any
abutment type.
When compared with a stock and cast abutment, the
cost of a CAD/CAM implant abutment presently lies
somewhere between the two. This expense is likely to
decrease over time as CAD/CAM systems for abutment
fabrication become commonplace. Conversely, costs of
manpower and labor-intensive laboratory processes are
likely to escalate, thereby increasing the cost of prepared
stock abutments or handmade cast custom abutments.