CAD/CAM (Computer Aided Designing/ Computer Aided Manufacturing) Technology in Dentistry has evolved drastically. Technology has always had a greater role in evolution and dentistry isn’t an exception. CAD/CAM Technology has enabled better work conditions in dental clinics, hospitals and in dental labs. In this post, we will discuss in detail about CAD-CAM Technology in dentistry, How it works, its architectures, applications, advantages and disadvantages.
What is CAD/CAM Technology in Dentistry
CAD/CAM is the short form of Computer Aided Designing and Computer Aided Manufacturing. In dentistry, it is a system that is used to improve the design and fabrication of dental restorations. CAD is used in the design and construction of veneers, implant abutments, crowns, inlays, onlays, fixed partial dentures, full-mouth reconstruction, and orthodontics while CAM is used in the manufacturing of the designed unit.
Fig. 1 – Introduction to CAD/CAM Technology in Dentistry
CAD/CAM was used for the first time in dentistry after a decade of its invention. This technology was initially used in the aircraft and automotive industries during the 1960s. The most important names in dental CAD/CAM development are Dr. François Duret of France, Dr. Werner Mormon of Switzerland, Dr.Dianne Rekow of the United States, and Matts Andersson of Sweden. Dr. Duret was the first dentist to develop a dental CAD/CAM device. He was making crowns based on an optical impression.
The optical impression of the abutment tooth was taken and then it was produced using a numerically controlled Milling machine. This was done in the year 1971. He delivered the first dental CAD/CAM restoration in 1983. He demonstrated his system at the French Dental Association’s International Congress in November 1985 and from then on, this system has grown leaps and bounds.
Fig. 2 – Design of Tooth using CAD/CAM Software
Architecture of CAD/CAM System in Dentistry
CAD/CAM system is usually made of three main components:
- Computerized Surface Digitization Using Scanners.
Computerized Surface Digitization Using Scanners
A scanner in dentistry is essentially a data collection device. It measures three-dimensional jaw and tooth structures. And then it transforms them into digital data sets.
There are two types of scanners:
- Optical Scanners
- Mechanical Scanners
They collect three-dimensional data using a process called “triangulation.”
In this method, the master cast is read mechanically. This is done by a ruby ball and then the three-dimensional data is obtained.
Various surface digitization techniques like Laser Scanning, Ultrasound, Magnetic Resonance Imaging, Computed Tomography, Contact Profilometry is employed
The data obtained from scanning is then transferred to CAD. A data set is produced via the software. This data set is different for each type of CAD/CAM application. A model of the product is fabricated by the CAD based on these inputs. The obtained data is also storable. It can be stored in different formats. The most common format is STL files. The CAD software then provides various dental restoration designs to the CAM unit.
CAM is production technology. It transforms the data set into a product through milling. The processing devices can be classified based on:
- Type of Milling
- According to the number of arms (Milling Axis)
- Production Concepts
Type of Milling
Based on the Type of Milling it is divided into two:
- Dry Milling
- Wet Milling
Is usually applied to Zirconium Oxide planks and requires a low degree of pre-sintering.
A spray of cool liquid Is present. It protects the Milling Diamond or Carbide Cutter to avoid damage due to heat. This is needed for metals and glass-ceramic.
Number of Arms (Milling Axis)
This can be further divided as follows:
- 3- Axis
- 4- Axis
- 5 -Axis
This milling device has movement in three spatial directions.
The tension bridge rotations acts as the fourth axis of movement.
The fifth axis is Added and it rotates the milling spindle.
This can be further divided based on the location of the components of the CAD/CAM systems. It can be divided as follows
- Chairside Production
- Lab Production
- Centralized Fabrication
The components of Dental CAD/CAM is in the dentist clinic.
The Production is carried out in the lab where the CAD/CAM production steps are carried out.
“Satellite Scanners” are present in the dental laboratory. These can connect with a production centre through the internet.
Fig. 3 – CAD/CAM system
How does CAD/CAM Technology in Dentistry Work
Producing ceramic restorations by CAD-CAM technology is precise than the conventional process. There are several phases or sequential steps that need to be followed to produce a restoration using CADCAM. Below figure sums up the steps involved for single visit and two visit preparation after the scanning.
- Intra Oral Scan– The dentist diagnoses and recommends several options that are best suited for the patient.
- Preparation of teeth– Preparing the teeth is the next step. The Process begins by the dentist altering the teeth in such a way that it can receive a prosthetic restoration.
- Taking Physical Impressions – The next step requires the dentist to take impressions on which further construction and casting of prosthetic restoration will be carried out.
- Dental Lab – Plaster Model is made from the impression, this forms the basis for the next steps at Dental Laboratory or at the Clinic itself.
- 3D Scan– 3D oral camera captures teeth and then the image is transferred to a computer and processed using the CAD-CAM software. These cameras have high accuracy and efficient.
- Modeling – CAD/CAM software models the teeth based on the inputs given.
- 3D Teeth Printing – Before teeth printing, ceramic blocks are installed in the milling. The ceramic block is fixed on the wheel. Then the Bridge is produced by milling process Milling machine develops the desired shape based on the instructions of a computer. The ceramic block is processed by turning on its axis. Also, a diamond disk. It moves up and down around the ceramic block and this is how the processing takes place. The movement of the diamond disc is commenced Through an electric rail.
- Cementation-Prosthetic restorations are cemented to the tooth with the help of special aesthetic cement.
Fig. 4 – Procedure of CAD/CAM Technology in Dentistry
Applications of CAD-CAM Technology in Dentistry
CAD-CAM can be used to produce the following in dentistry:
- Fixed partial dentures
- Implant abutment
- Full-mouth reconstruction
Advantages of CAD-CAM Technology in Dentistry
The advantages of CAD-CAM Technology in Dentistry include:
- CAD/CAM restorations are high in quality.
- It gives a natural appearance because the ceramic blocks can emulate enamel.
- The measurements and fabrication are exact.
- Has the potential for saving time and reduce costs if milling is in the clinic.
- Digital scans are faster and easier.
- It can provide better adaptation on the teeth, marginal dental sealing and ensures better long-term performance.
Disadvantages of CAD-CAM Technology in Dentistry
The disadvantages include:
- The initial cost is high.
- Technical proficiency required.
Any progress in the field of information and communication technologies enters all fields including dentistry. The efficiency of CAD-CAM is proof of the usefulness of applying IT in dentistry. The expansion of information and communication technologies is sure to have a stronger impact on the diagnosis, treatment, and monitoring of therapeutic effects. It will help to provide a high level of aesthetics.