CAD/ CAM IN DENTISTRY
The abbreviation CAD or CAM in dentistry stands for Computer Aided Design or Computer Aided Manufacturing (European Society of Cosmetic Dentistry, 2016). The utility of CAD/ CAM has been quite extensive in the modern world of dentistry, mainly in the field of dentistry laboratory. In an article by some eminent research workers, the concept of CAM/ CAD was termed as “A novel procedure for virtual dental implant planning” (L et al., 2008). They also called the same as a meeting of the 3D X- rays with CAD/ CAM. In another article, it was said that the development of CAD/ CAM system in dentistry has been brought about in order to solve three important challenges. These challenges were:
Ensuring proper strength of the restoration
Creation of restorations which are very similar in appearance to those of the naturals.
Making the whole process of teeth restoration faster, easier and comparatively more accurate (Davidowitz & Kotick, 2011).
In general, a system of the CAD/ CAM includes three different modules. They are as follows:
Scanner
Design Software Package
Milling Machine
The scanner performs the function of scanning the solid model and subsequently converting it into the form of a digital data. The scanning systems that are being used currently can bring out full arch dental impression with a very high level of precision. There is no difference in the powder- free scanning system results when compared to those of the surface pre- treatment ones (A & A, 2012). The design software package does the function of designing and modifying the digital model. The third module that is the milling machine performs the function of milling the model design with the help of a suitable material (Lee & Yau, 2006).
The materials used for the processing by CAD/ CAM devices depend completely on the system of production. Some of the milling devices are designed especially for producing Zirconium oxide frames. Other devices may cover all the different types of materials ranging from glass ceramics (including high performance ceramics) to the resins. Below is the list of certain materials which can be processed in a CAD/ CAM system:
Metal
Resin
Silica based ceramic
Infiltration ceramic
Oxide high performance ceramic (Example: Aluminium oxide, Yttrium stabilised Zirconium oxide)
History of CAD/ CAM
The application of CAD/ CAM in the field of dentistry emerged in Europe in the decade 1970- 1980. The system has gained extremely high momentum in the last 25 years (Davidowitz & Kotick, 2011). The first ever system which was introduced for aesthetic purposes in the field of dentistry was CEREC1 or Sirona. Another CEREC 3D System was brought about in the year 2003. It used the technique of computer technology and intraoral imaging for the fabrication of dental restorations within the clinical setting in order to reduce the time of treatment. High quality optical lens are used for capturing the images of the tooth which requires to be worked upon. The computer then creates a virtual model of that particular tooth or all the teeth of the patient. The virtual model is then designed by the dentist with the assistance of the CAD/ CAM software. The milling machine ultimately mills out the exact design out of a ceramic block. This is then placed into the mouth of the patient. The whole process is completely within a time period of 60 minutes only, within the clinical setup. The substance which is used for the purpose of restoration is very similar to that of the natural teeth in terms of their strength, functioning and beauty. The most common indications for which such a procedure is adopted are onlays, inlays, crowns or veneers restoration.
CAD/ CAM systems are now being used widely in various dental laboratories. Primarily, this system is used for the single unit or multiple unit bridge and crown restoration. The steps depicted below are followed in the process of fabricating crown and bridge restorations:
Preparation of a stone model from the impression of the teeth
Scanning of the stone model followed by conversion into digital data.
Designing software used for laying out the design of the model.
The restoration is finally milled out with the help of the milling machine.
Advantages of the System
The CAD/ CAM system is far more superior to the traditional or conventional methods. The products are stronger and more durable than the ones used in the traditional methods. This fact has been proved by repeated examinations. When compared with directly fabricated fixed partial dentures, the CAD/ CAM fabricated fixed partial dentures showed better durability and more strength even when both were manufactured using the same basic materials (Alt, Hannig, Wöstmann & Balkenhol, 2011). Unlike the traditional restoration materials, these materials are not subjected to extremely high temperatures during the process of milling. Furthermore, the use of the computerized technology makes the process more accurate and the restorations fit better than their traditional counterparts. The system reduces the chair- side time of the dentist which is otherwise required for the restoration process. It is also called to be cost effective in certain cases and for certain patients (Drago, 2006). It helps in better planning during dental surgeries related to implants. The dentists, with the help of the CAD/ CAM system can plan out the best implant of appropriate thickness before the surgery commences (Patel, 2010). Milled restorations are better than handmade restorations; this has been studied and proved through recurrent researches (Christensen, 2008). Resin manufactured posterior occlusal veneers show higher degree of fatigue resistance than others (Magne, Schlichting, Maia & Baratieri, 2010). Ceramic restoratives show higher degree of biocompatibility and are better from the aesthetic point of view too (Li, Chow & Matinlinna, 2014).
Disadvantages of the System
Being a computer and software based system, there do exist some limitations in terms of functionalities. It cannot replace the skills and knowledge of the dentist. The dentist and the laboratory technicians must have good knowledge about the method of handling the machines, taking proper impressions and proper scanning (Dental Tribune America, 2012). The whole concept does have the potential to bring about great improvements in the field of dentistry, but at the same time, the huge cost of setting up the machineries may not be affordable or feasible for small scale dental laboratories (Beuer, Schweiger & Edelhoff, 2008).
Turbodent System
A major development in the field of CAD/ CAM is the introduction of the turbodent system or the TDS. This is an integrated and advanced version of the CAD/ CAM. The TDS consists of the following modules:
Scanner
Designer
Cutter
Clinically, the TDS is used for various types of implant restorations, onlays, veneers, inlays, crowns and bridges. The development of an implant surgical planning and an adequate template system gives proper guidance during an implant surgery. It also aids in integrating the restorative planning from provisional to permanent restoration during the surgical planning (Lee & Yau, 2006).
Future Perspectives
CAD/ CAM system has already brought about revolutionary changes in the world of medicine. It has brought about storms of change in the dental clinics and dental laboratories (Skramstad, 2015). It has taken the crown and bridge restoration to a completely different level (Miyazaki & Hotta, 2011). The introduction of CAM/ CAD system in the field of dentistry will certainly bring about more improvements in the Quality of Life or the QOL and general health of the aging sector of the world (MIYAZAKI, HOTTA, KUNII, KURIYAMA & TAMAKI, 2009). The use of CAD/ CAM system can also be employed equally for the diagnostic purpose. Some of the diseases like maxillary sinusitis, arteriosclerosis and osteoporosis can be diagnosed with the help of CAD/ CAM. It can help in detecting the dental or maxillofacial lesions too. The radiographic images obtained while scanning are used as diagnostic tools (Katsumata & Fujita, 2014). Working on the manufacturing quality of the prostheses is extremely important; it will help in further improvement in this field (Renne, McGill, Forshee, DeFee & Mennito, 2012). The system even after having immense growth potential is not been accepted at a large scale yet. The medical professionals are reluctant to accept the new technology (Battersby, 2014). Further enhancement of knowledge may bring about better use of this technology.
References
A, E., & A, M. (2012). Influence of scanning strategies on the accuracy of digital intraoral scanning systems. International Journal Of Computerized Dentistry, 16(1), 11-21. Retrieved from http://europepmc.org/abstract/med/23641661
Alt, V., Hannig, M., Wöstmann, B., & Balkenhol, M. (2011). Fracture strength of temporary fixed partial dentures: CAD/CAM versus directly fabricated restorations. Dental Materials, 27(4), 339-347. http://dx.doi.org/10.1016/j.dental.2010.11.012
Battersby, J. (2014). CAD/CAM – The end for dental labs or a new beginning?. Dentistry IQ. Retrieved 23 January 2016, from http://www.dentistryiq.com/articles/2014/05/cad-cam-the-end-for-dental-labs-or-a-new-beginning.html
Beuer, F., Schweiger, J., & Edelhoff, D. (2008). Digital dentistry: an overview of recent developments for CAD/CAM generated restorations. BDJ, 204(9), 505-511. http://dx.doi.org/10.1038/sj.bdj.2008.350
Christensen, G. (2008). In-Office CAD/CAM Milling of Restorations. The Journal Of The American Dental Association, 139(1), 83-85. http://dx.doi.org/10.14219/jada.archive.2008.0025
Davidowitz, G., & Kotick, P. (2011). The Use of CAD/CAM in Dentistry. Dental Clinics Of North America, 55(3), 559-570. http://dx.doi.org/10.1016/j.cden.2011.02.011
Davidowitz, G., & Kotick, P. (2011). The Use of CAD/CAM in Dentistry. Dental Clinics Of North America, 55(3), 559-570. http://dx.doi.org/10.1016/j.cden.2011.02.011
Dental Tribune America,. (2012). The sunny side of CAD/CAM | Dental Tribune International. Retrieved 23 January 2016, from http://www.dental-tribune.com/articles/specialities/dental_lab/8020_the_sunny_side_of_cadcam.html
Drago, C. (2006). Two new clinical/laboratory protocols for CAD/CAM implant restorations. The Journal Of The American Dental Association, 137(6), 794-800. http://dx.doi.org/10.14219/jada.archive.2006.0292
European Society of Cosmetic Dentistry,. (2016). CAD/CAM Dentistry | ESCD – Europen Society of Cosmetic Dentistry. Retrieved 23 January 2016, from http://www.escdonline.eu/cosmetic-dentistry/cadcam-dentistry/
Katsumata, A., & Fujita, H. (2014). Progress of computer-aided detection/diagnosis (CAD) in dentistry.Japanese Dental Science Review, 50(3), 63-68.
L, R., J, N., T, D., D, R., J, C., & VE, K. et al. (2008). 3D X-ray meets CAD/CAM dentistry: a novel procedure for virtual dental implant planning. International Journal Of Computerized Dentistry,12(1), 29-40. Retrieved from http://europepmc.org/abstract/med/19213358
Lee, & Yau,. (2006). CAD/CAM Use in the Dental Laboratory | Dentistry Today. Dentistrytoday.com. Retrieved 23 January 2016, from http://www.dentistrytoday.com/laboratory/1341--sp-489580286
Li, R., Chow, T., & Matinlinna, J. (2014). Ceramic dental biomaterials and CAD/CAM technology: State of the art. Journal Of Prosthodontic Research, 58(4), 208-216. http://dx.doi.org/10.1016/j.jpor.2014.07.003
Magne, P., Schlichting, L., Maia, H., & Baratieri, L. (2010). In vitro fatigue resistance of CAD/CAM composite resin and ceramic posterior occlusal veneers. The Journal Of Prosthetic Dentistry,104(3), 149-157. http://dx.doi.org/10.1016/s0022-3913(10)60111-4
Miyazaki, T., & Hotta, Y. (2011). CAD/CAM systems available for the fabrication of crown and bridge restorations. Australian Dental Journal, 56, 97-106. http://dx.doi.org/10.1111/j.1834-7819.2010.01300.x
MIYAZAKI, T., HOTTA, Y., KUNII, J., KURIYAMA, S., & TAMAKI, Y. (2009). A review of dental CAD/CAM: current status and future perspectives from 20 years of experience. Dent. Mater. J.,28(1), 44-56. http://dx.doi.org/10.4012/dmj.28.44
Patel, N. (2010). Integrating Three-Dimensional Digital Technologies for Comprehensive Implant Dentistry. The Journal Of The American Dental Association, 141, 20S-24S. http://dx.doi.org/10.14219/jada.archive.2010.0357
Renne, W., McGill, S., Forshee, K., DeFee, M., & Mennito, A. (2012). Predicting marginal fit of CAD/CAM crowns based on the presence or absence of common preparation errors. The Journal Of Prosthetic Dentistry, 108(5), 310-315. http://dx.doi.org/10.1016/s0022-3913(12)60183-8
Skramstad, M. (2015). The Clinical Application of CAD/CAM Technology and Materials. Dental Learning. Retrieved 23 January 2016, from http://www.dentallearning.net/clinical-application-cadcam-technology-and-materials/take-course
