CEREC
Encyclopedia
CEREC is a dental restoration
product that allows a dental practitioner to produce an indirect ceramic
dental
restoration using a variety of computer
assisted technologies, including 3D photography and CAD/CAM. With CEREC, teeth can be restored in a single sitting with the patient, rather than the multiple sittings required with earlier techniques. Additionally, with the latest software and hardware updates, crown
s, veneer
s, onlay
s and inlays can be prepared, using different types of ceramic material.
Single Appointment Dental Care:
Most dental restorative methods require more than one visit to the dentist. This means that on the first visit, you get an injection of anesthesia, your tooth prepared, an impression taken, and a temporary restoration put on your tooth. You make a second appointment for a couple of weeks later, get another injection, have the temporary removed and have a permanent restoration put on. With CEREC, the procedure is done in a single appointment, start to finish. With CEREC, the dentist can use strong, tooth colored ceramic materials to restore your teeth to their natural beauty and function.
Finest Dental Materials:
These materials match the composition of natural tooth structure. This means when hot food or cold drinks are consumed the restoration and tooth expand and contract at almost equal rates. Also, the materials are chemically bonded to your tooth, so the dentist can save as much healthy tooth structure as possible while providing you with a dental restoration that strengthens your tooth.
The cavity preparation is first photograph
ed and stored as a three dimensional
digital model and proprietary software
is then used to approximate the restoration shape using biogeneric comparisons to surrounding teeth. The practitioner then refines that model using 3D CAD software. When the design phase is complete, the information is sent wirelessly to the milling unit which mills the actual restoration from a solid block of material using diamond
burs. The restoration is bonded to the tooth using a resin cement which bonds to both the restoration as well as the tooth itself.
Database:
This design mode uses a library of tooth shapes that is stored on the computer to suggest the shape of the proposed restoration. Most commonly a recording of the bite registration (the imprint of the opposing or antagonist tooth in a wax like or rubbery material) is also added to the data the software can use when deciding the proposal. This data together with a 3D optical impression of the prepared tooth establishes the approximate zone with which the new restoration can exist. The proposed restoration can then be morphed to fit into this zone in an anatomically and functionally correct position. The dentist can then make correction to this proposal as he sees fit and then send it to the milling unit for completion.
and dentin. It also wears away at approximately the same rate as enamel. There is also a composite material available which has some advantages in restoring smaller inlay type restorations.
2. Because the restoration is an approximation an exact match of the patients tooth and bite is not ensured. This can result in both a poor cosmetic match along with a misaligned bite, due to poor preparation work, image taking, and inability to define the insertion access.
Dental restoration
A dental restoration or dental filling is a dental restorative material used to restore the function, integrity and morphology of missing tooth structure. The structural loss typically results from caries or external trauma. It is also lost intentionally during tooth preparation to improve the...
product that allows a dental practitioner to produce an indirect ceramic
Ceramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...
dental
Dentistry
Dentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered...
restoration using a variety of computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
assisted technologies, including 3D photography and CAD/CAM. With CEREC, teeth can be restored in a single sitting with the patient, rather than the multiple sittings required with earlier techniques. Additionally, with the latest software and hardware updates, crown
Crown (dentistry)
A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant. Crowns are often needed when a large cavity threatens the ongoing health of a tooth. They are typically bonded to the tooth using a dental cement. Crowns can be made from many materials, which...
s, veneer
Veneer (dentistry)
In dentistry, a veneer is a thin layer of restorative material placed over a tooth surface, either to improve the aesthetics of a tooth, or to protect a damaged tooth surface. There are two main types of material used to fabricate a veneer, composite and dental porcelain...
s, onlay
Onlay
In dentistry, an inlay is an indirect restoration consisting of a solid substance fitted to a cavity in a tooth and cemented into place. An onlay is the same as an inlay, except that it extends to replace a cusp...
s and inlays can be prepared, using different types of ceramic material.
Single Appointment Dental Care:
Most dental restorative methods require more than one visit to the dentist. This means that on the first visit, you get an injection of anesthesia, your tooth prepared, an impression taken, and a temporary restoration put on your tooth. You make a second appointment for a couple of weeks later, get another injection, have the temporary removed and have a permanent restoration put on. With CEREC, the procedure is done in a single appointment, start to finish. With CEREC, the dentist can use strong, tooth colored ceramic materials to restore your teeth to their natural beauty and function.
Finest Dental Materials:
These materials match the composition of natural tooth structure. This means when hot food or cold drinks are consumed the restoration and tooth expand and contract at almost equal rates. Also, the materials are chemically bonded to your tooth, so the dentist can save as much healthy tooth structure as possible while providing you with a dental restoration that strengthens your tooth.
Technology
Photograph
A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...
ed and stored as a three dimensional
Dimension
In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...
digital model and proprietary software
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
is then used to approximate the restoration shape using biogeneric comparisons to surrounding teeth. The practitioner then refines that model using 3D CAD software. When the design phase is complete, the information is sent wirelessly to the milling unit which mills the actual restoration from a solid block of material using diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
burs. The restoration is bonded to the tooth using a resin cement which bonds to both the restoration as well as the tooth itself.
History
The system is manufactured by "Sirona Dental" in Bensheim, Germany .- 1980 - Development of the CEREC method at the University of Zurich W. Mörmann, M. Brandestini).
- 1985 - Treatment of the first patient with CEREC (University of Zurich, material: VITABLOCS Mark I).
- 1986 - Siemens acquires the license to market and further develop the CEREC equipment.
- 1987 - CEREC 1 is introduced (chief indication: single and dual-surface inlays; material: VITABLOCS Mark II).
- 1990 - International CEREC Symposium at the University of Zurich.
- 1991 - Hydraulic machining drive replaced by an electronically controlled motor.
- 1994 - CEREC 2 is introduced (range of indications: inlays, onlays, veneers).
- 1996 - CAD/CAM Symposium to mark a decade of CEREC (University of Zurich).
- 1997 - Sirona was formed as the result of the sale of the Dental Division of Siemens AG.
- 1997 - CROWN 1.0 program for producing full-ceramic posterior crowns.
- 1998 - Second material manufacturer partnership is formed (lvoclar, ProCAD).
- 1998 - CROWN 1.11 program for producing posterior and anterior restorations.
- 2000 - CEREC 3 is introduced (compact Windows-based CAD/CAM system).
- 2000 - Third material manufacturer partnership is formed (3M Paradigm MZ100).
- 2002 - More than 2,500 CEREC users in the United States and over 5,000,000 CEREC restorations placed worldwide.
- 2003 - 3D software version is released, allowing users to see 3D views of teeth and models.
- 2005 - IPS e.max CAD by Ivoclar Vivadent launches for CEREC, 360MPa flexural strength all ceramic restorations
- 2006 - CEREC Celebrates 20 Years.
- 2006 - Sirona releases BIOGENERIC version of software. This software allows for the machine to accurately reconstruct the missing tooth shape and surface.
- 2007 - More than 23,000 CEREC users world wide.
- 2008 - Sirona release the MCXL milling unit, this milling unit can produce a crown in 4 mins.
- 2009 - Sirona release CEREC Acquisition Center (AC) powered by Bluecam
- 2010 - CEREC Celebrates 25 Years.
Technique
The treating dentist prepares the tooth being restored either as a crown, inlay, onlay or veneer. The tooth is then powder sprayed with a thin layer of blue anti-reflective contrast medium, imaged by a 3D imaging camera and uploaded to the CEREC computer. Using the proprietary CEREC software in various modes, a restoration can be designed to restore the tooth to its appropriate form and function. This data on this restoration is stored in a file and is sent via wireless serial transmission or direct wiring to a milling machine. The restoration can then be milled out of a solid ceramic or composite block. Milling time varies from as little as four minutes to as long as twenty depending on the complexity of the restoration and the version of the milling unit.Design Methods
The design software for the CEREC system has undergone significant changes in the years since the technique was first introduced by Professor Mormann. Currently, a dentist can choose from four major design approaches.Database:
This design mode uses a library of tooth shapes that is stored on the computer to suggest the shape of the proposed restoration. Most commonly a recording of the bite registration (the imprint of the opposing or antagonist tooth in a wax like or rubbery material) is also added to the data the software can use when deciding the proposal. This data together with a 3D optical impression of the prepared tooth establishes the approximate zone with which the new restoration can exist. The proposed restoration can then be morphed to fit into this zone in an anatomically and functionally correct position. The dentist can then make correction to this proposal as he sees fit and then send it to the milling unit for completion.
Materials
The ceramic material has some properties that make it very suitable for use in dental restorations. It expands and contracts in response to temperature changes at a rate approximately half-way between those of enamelTooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
and dentin. It also wears away at approximately the same rate as enamel. There is also a composite material available which has some advantages in restoring smaller inlay type restorations.
Advantages
- Time savings. Patients usually only have to go one time, as opposed to two trips for a traditional crown; this also reduces the number of local anesthetic injections (shots) needed.
- More conservation of tooth structure. Oftentimes a partial coverage restoration can be completed vs a full conventional crown.
- Stronger porcelain. Milled ceramic is stronger than hand layered and pressed.
- Aesthetics. Homogeneous porcelain blends in better than other porcelains.
- Natural. Ability to copy what was there previously can, but not necessarily, yield restorations that are duplicates of the pre-prepared tooth.
Disadvantages
1. Requires investment of time and money for dentist to obtain and learn.2. Because the restoration is an approximation an exact match of the patients tooth and bite is not ensured. This can result in both a poor cosmetic match along with a misaligned bite, due to poor preparation work, image taking, and inability to define the insertion access.