REVIEW ARTICLE

A REVIEW ON CAD CAM IN DENTISTRY

Umer bin Irfan1 BDS
Kashif Aslam2 BDS, MSc
3
Rizwan Nadim BDS, MSc

ABSTRACT: Evidence suggest that CAD CAM was in use in the ancient times. In dentistry, CAD CAM was
introduced in 1970s. Since then, its use in dentistry has been increasing day by day. Many companies are developing
new CAD CAM systems. With CAD CAM, dentists can get high quality inlays, onlays, implant abutments, cast
partial dentures, crowns, bridges etc. Maxillo-facial prosthesis and orthodontic clear aligners are also being produced
by CAD CAM. Apart from quality and quick production of restorations, cost and difficult usage of CAD CAM are
the reasons which are causing hurdles in mass production of these restorations. This review is about a brief history
types and current clinical applications of this modality.
HOW TO CITE: Irfan UB, Aslam K, Nadim R. A review on cad cam in dentistry. J Pak Dent Assoc 2015; 24(3):112-
116.
Received: October 10 2015, Accepted: October 26 2015

INTRODUCTION HISTORY OF CAD CAM

O
ver the past 30 years, CAD CAM (computer The history of dentistry is as old as human civilization
aided design computer aided machine) has in the ancient times. Hippocrates and Aristotle, have
gained popularity and confidence of the written many things about dental diseases and their
profession and patients alike. It has provided ease, treatments.1 In the eastern world, ancient Chinese literature
comfort, and quality of restoration to both the dentists is available regarding silver pastes (primitive amalgam).
and dental lab technician. Moreover, restorations which As the civilization was getting developed, newer and
are being produced through cad cam these days, are newer findings kept on becoming the part of dentistry.
more durable, more marginally adaptive, more Commercial production of porcelain teeth by Samuel
esthetically pleasing and more faster in fabrication as Stockton, introduction of amalgam by Crawcours and
compared to the conventional restorations. But despite origination of cohesive gold foil method by Robert Arthur
of these advantages, cost is the major issue which has all have brought revolution in the field of dentistry.1 So
limited its use. Because of the financial constraints, in revolutionization has become the habit of dentistry.
the under developed countries, dentists are still reluctant The history of cad cam itself is old. In ancient Egypt,
in using cad cam However, one should not overlook the Greece, and Rome, evidences suggest that cad cam was
benefits which CAD CAM provides. Accuracy and being practiced there even. Even Leonardo di Vinci has
quality of CAD CAM in producing inlays, on lays, shown in his works, the use of modern graphics
implant abutments, fixed partial dentures, crowns and convention. 2 But Euclid of Alexandria, the great
bridges is acceptable and improving every day. This mathematician, can truly be regarded as the person behind
review article highlights the history and current the modern CAD soft ware because today's CAD software
indications of CAD CAM. It also provides information is based on Euclid's axioms and postulates, which laid
that how it works and what can be itsadvantages and the foundation of Euclidian geometry.3,4 Iven Sutherland
disadvantages. in early 1960s, developed the CAD software (sketchpad)
but before that Dr. Patrick J. Hanratty, had already designed
1. Dept. of Prosthodontics, Dow Dental College, DUHS, Karachi.
2. Assistant Professor Dept. Of Prosthodontics Dow Dental College, DUHS, Karachi, first numerically controlled CAM that was named as
Kings College, London. Pronto. So Dr Patrick is called as Father of CAD CAM.3,4
3. Assistant Professor Dept. Of Community Dentistry Dow Dental College, DUHS,
Karachi. The introduction of CAD CAM in dentistry begins
Corresponding author: “Dr Kashif Aslam” < taimoor.links@gmail.com > with the work of Dr Duret. He took optical impression

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 Irfan UB / Aslam K / Nadim R A review on cad cam in dentistry

of an abutment tooth after cutting and then with the help Types of CAD CAM Production
of that impression he fabricated a crown by using CAD CAM restorations can be produced by three different
numerically control machine. He did that miracle in the ways.
field of dentistry in the year 1971.5 Later on Dr Duret a) Chair side production
along with his team mates, worked on Sopha system and b) Laboratory production
introduced it but due to few reasons that system was not c) Centralized production
generally accepted by the people. 6 Mormann was
the person who introduced first commercially designed 1. Chair side production:
CAD CAM system in the year 1985 and given the name It involves taking an impression chair side and then
of CEREC to that system. 7 He fabricated an inlay producing the restoration at the same time. It doesn't
from a ceramic block after taking digital impression from require involvement of the laboratory and the patient/s
intra oral camera. That was bit easy as compared to take can have their restoration at the same appointment10.
impression of a prepared abutment tooth. Now this Obviously it saves times but it is expensive and puts extra
system is being used all over the world successfully cost on the patient.
for the fabrication of crowns, inlays, onlays etc.
Dr Andersson developed Procera system in the mid-1980s 2. Laboratory production
and worked on titanium as a substitute of nickel chromium It is somewhat similar to the conventional method. The
alloys.8 Previously, gold alloys were being used, but due dentist takes the impression & sends it to the lab, where
to increase in prices of gold, people had to think of other works carried out by the lab technician.
substitutes. Dr Andersson came up with titanium because
allergies were reported with nickel chromium. 3. Centralized production
In centralized production of the restoration, an impression
Fig 1: Summarizes the major advancements in CAD CAM. is taken and a master cast is digitized in the lab, then it
sends to outsource laboratory through internet. In that
In 1971, Dr Duret designed 1st outsource lab, the final restoration is fabricated which
CAD CAM
sends back to the dentist. The idea is right in the sense
In 1985, Dr Mormann designed that it requires digitizer and software only to perform the
CEREC system
initial steps and a high quality restoration.10
In 1980s, Dr Andersson
introduction Procera
METHODS OF DATA ACQUISITION IN CAD CAM
In 1994, Siemens made
CEREC 2 system
There are several methods by which data can be
In 2000, Sirona introduced collected for CAD.
CEREC 3 & InLab
1) Intra oral scanning
2) Contact and non - contact digitization
3) Ct scan or MRI
CEREC 2 was introduced in 1994 by Siemens. This
system was based on two dimensional principles and Fig 2
capable of producing inlay, onlay, veneers, partial & full
crowns and copings. Currently 3rd generation of CEREC DIGITAL IMPRESSION CONVENTIONAL IMPRESSION

is in use, which is capable of producing inlay, onlay,

veneers, partial & full crowns, copings as well as virtual 1. Less patient discomfort 1. More patient discomfort
automatic occlusal adjustment. This system was introduced 2. Takes less time 2. Takes more time
by Sirona in 2005. This system is basically the advanced 3. No need for model VS 3. Model pouring is needed
form of CEREC 3 which was earlier introduced in 2000 poring 4. Shelves are required to
by Sirona but that system worked on two dimensional 4. No extra space is keep the models esp.in
required to keep the orthodontics
principles and was not able to provide virtual automatic
models
occlusal adjustments.9

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 Irfan UB / Aslam K / Nadim R A review on cad cam in dentistry

1. Intra oral scanning 1. Prosthodontics:

There are several intra oral scanners available in market Whether it is removable or fixed prosthodontics,
namely CEREC® - by Sirona Dental System GMBH fabricating them through CAD CAM is becoming the
(DE), Lava™ C.O.S. - by 3M ESPE (US), iTero - by choice of almost every leading dentist.
C A D E N T LT D ( I L ) a n d E 4 D - b y D 4 D a) Removable Complete Dentures:
TECHNOLOGIES, LLC (US) etc. What these systems A group of Japanese investigators named Maeda et
do, they take 3-D virtual picture of the prepared tooth/teeth al, published a report in 1994, in which they proposed
and the adjacent structures, directly into the patient's that removable complete dentures can be fabricated using
mouth Later on these images transfer to the CAD for CAD Cam technology.15 Since then many researches have
designing of the prosthesis.11 A comparison of intra oral been proposed regarding fabrication of removable
scanning which is also called as digital impression and complete dentures through CAD CAM but no clinical
conventional impression is given below. reports or trials have been published yet. Only 2 of the
But despite of the advantages of digital impression manufacturers claim that they manufacture RCD through
technique, there are certain things which need to be CAD CAM.16
considered while taking digital impressions. The dentist,
who is taking intra oral pictures, must take care of moisture b) Removable Partial Dentures
control. Soft tissue retraction and hemostasis should be Partial denture framework can be produced through
considered too.12 CAD CAM by using additive prototyping technique.17,18

2. Contact & Non - Contact Digitizing c) Crowns / Bridges

This method involves taking an conventional Zirconia is the widely used material for the fabrication
impression and then after producing a model, transferring of crown and bridge through CAD CAM. However, metal
of that data into CAD through probe digitization ( & porcelain crown & bridge can also be fabricated through
contact) or laser light ( non - Contact ). In contact CAD CAM. A study suggests that zirconia exhibits
digitizing or scanning, a contact probe reads the anatomy acceptable clinical results.19
of the model by following the contour of the physical
structure. In non-contact scanning, apart from laser light, d) Inlay, Onlay & Veneers
optics and charged -coupled devices are also used. These restorations are also being produced through
Obviously, this technique doesn't require any physical CAD CAM.20 A study says that inlays & onlays, produced
contact with the model, but precision in recording the through CAD CAM, have a higher survival rate. 21
details is required. It is assumed that, in comparison to
contact scanning, this technique is relatively quick in 2. Orthodontics
gathering the data.13 In orthodontics, clear aligners have gained so much
popularity due to esthetics. Now patients don't have to
3. Ct scan /MRI: show metallic brackets and wires. The credit goes to CAD
Computed Tomography (CT & Magnetic Resonance CAM again.22 Also lingual bracket system is in demand
Imaging (MRI) are newer techniques for data acquisition due to its invisibility. The wires and bracket system for
for CAD Cam.By this method, individual images can be the lingual bracket system is fabricated through CAD
taken and then can be transferred to CAD. CT scan utilizes CAM.23 Orthodontic mini implants can also be positioned
radiation for its data acquisition but MRI doesn't. For soft using CAD CAM technology.24
tissue modelling, MRI data is suitable and for hard tissue
(bone) modelling, CT data can be used.14 3. Implant Dentistry:
Implant abutments and surgical guides for the
USES OF CAD CAM IN DENTISTRY placement of implants are being produced through CAD
CAM these days.25
CAD CAM is being used in almost every field of
dentistry these days. Following are its some of the uses 4. Maxillo-Facial Prosthetics:
in different specialties of dentistry: A study shows the difference in between the outcome of

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 Irfan UB / Aslam K / Nadim R A review on cad cam in dentistry

the artificial ear prosthesis carved by hand & fabricated 2. Zeid, Ibrahim,Cad/Cam Theory and Practice,1991,
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ADVANTAGES AND DISADVANTAGES OF Dent Jour. 2011;56:97-106.
CAD CAM 7. Mormann WH, Brandestini M, Lutz F, Barbakow
F.Chairside Computer Aided Direct Ceramic Inlays.
If we compare the advantages of CAD CAM Quintessence Int 1989;20:329-339.
restorations over the conventional one, we will definitely 8. T Miyazaki, Y Hotta, J Kunii, S Kuriyama, Y
place CAD CAM restorations on top. They provide us Tamaki.A review of dental CAD CAM: Current status
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Scanning of intra oral tissues takes less time than Mat Jour 2009;28:44-56.
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available, the patients can get their restorations in one system.J Am Dent Assoc 2006;137:7S-13S.
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570.
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