CAD\CAM IN DINTISTRY

BY:Dr.Duha Ali

CAD/CAM dentistry

CAD

(Computer-Aided Design)

CAM

(Computer-Aided Manufacturing)

is an area of dentistry utilizing CAD/CAM technologies to produce different types of dental restorations, including crowns, crownlays ,veneers, inlays and onlays, fixed bridges, dental implant restorations and orthodontic appliances.

CAD/CAM usage in dentistry began in the mid 1980s. Initially, this computerized technology was cumbersome and basically a novelty, requiring inordinate amounts of time to produce a viable product. This reality limited its practical usefulness to the dental laboratory setting, rather than the dental practice as time constraints precluded chair side (in the dental office) usage. As adjunctive techniques ,software, and available materials improved over time, CAD/CAM usage in the dental practice setting became a reality. Thus "chair side" CAD/CAM technology affords the practitioner the ability to produce tooth-colored prosthetic dental restorations on-site in a matter of hours

History:

The concept of chairside CAD/CAM restoration differs from conventional dentistry in that the prosthesis is typically luted or bonded in place the same day, whereas conventional dental prosthesis of larger size such as crowns have temporaries placed for several weeks while a dental laboratory produces the restoration off-site

The patient returns weeks later, the temporary is removed, and then the laboratory made crown is then cemented or bonded in place. Because the CAD/CAM restoration is bonded the same day, the principles applied in preparing the tooth for a crown or other prosthesis are typically more conservative. Bonding is more effective on tooth enamel. As such, the teeth need to be prepared such that the enamel layer is not removed to expose the tooth dentin. Permanent bonding of the restoration is best achieved by bonding the fitting surfaces of the restoration to the prepared enamel surfaces of the tooth. Consequently, less tooth surface removal is usually the normal.

Process:

Typically CAD/CAM dental restorations are milled from solid blocks of ceramic or composite resin closely matching the basic shade of the restored tooth. Metal alloys may also be milled or otherwise digitally

produced..

After decayed or broken areas of the tooth are corrected by the dentist, an image (scan) is taken of the prepared tooth and the surrounding teeth. This image, called a digital impression, draws .the data into a computer

Then proprietary software is used to create a replacement part for the missing areas of the tooth, essentially creating a virtual restoration. This is called reverse engineering. The software sends this virtual data to a milling machine where the replacement part for the defect (the dental restoration) is carved out of a solid block of ceramic or composite resin. Stains and glazes are fired to the surfaces of the milled ceramic crown or bridge to correct the otherwise monochromatic appearance of the restoration. The resulting restoration can then be adjusted in the patient’s mouth and cemented or bonded in place

CAD/CAM dental software products

CEREC, software for manufacturing crowns, veneers, onlays and inlays can be prepared, using different types of ceramic material.

Delcam dental solutions, for the design and manufacture of copings and bridge frameworks, including full crowns, abutments, dental bars, inlays/onlays and implant bridges

CEREC

DELCAM

the components of the Cerec unit?

1 .The Acquisition Unit:The acquisition unit is made up of a tower with a computer inside it, an lcd computer screen, camera unit for imaging teeth and program software for creating dental restorations.

2 .The Milling Unit

This is a box shaped chamber that is separate from the acquisition unit. It wirelessly receives directions from the acquisition unit and mills(cuts) crowns, onlays, inlays and veneers from porcelain or composite(acrylic) blocks. The milling unit featurs a self contained water supply and 2 diamond coated burs that create the specified shape of computer designed restorations.

2. The Milling Unit

Why Perform CEREC in Dentistry? What are its Benefits?

1 .Saves Time: Most restorations are completed in a single visit. That means NO return trips to the dentist.

2 .No Temporaries: Receiving crowns or porcelain fillings in a single visit means not 2-3 week wait with temporary material on your tooth while a lab makes the permanent restoration. ---That means NO temporaries to fall off or out inconveniencing the patient further by returning to the office to have it replaced.

3 .Less Novacaine: Because single visits for Cerec Dentistry are the standard.

.

4 .Less Tooth Drilling: Because Cerec restorations are placed with extremely strong cement(glue), more tooth structure can generally be preserved during a procedure.

5 .Cerec Restorations are very Accurate: These precisions restorations are performed under high magnification on the computer screen, greatly enhancing accuracy levels.

6 .Cerec Restorations are very strong having published 10 year success rates exceeding 90% survival .

Photo of Cerec Restorations=

BEFORE

AFTER

dental scannersSolutionix, 3D dental

scanners, for the quality measurement of dental models and impressions.

Straumann CARES Digital Solutions, CS2 Scanner

3DScanners

The most Comprehensive Open Platform within Digital Dentistry

Applications:

Model scanning from single unit to full archFull arch scanning with palate for partial frameworksMulti – die scanning & designing capabilitiesScanning occlusions using check-bites or on positive modelsusing our patented “axis-finder” techniqueImpression scanning up to full archReplication of wax-upsScanning implants for custom abutments

CROWN & BRIDGEDesign: single unit to full bridge ,

simple coping, clinical coping, dental band, ¾crown, full crown, veneer Managed by

clinical parametersCustom anatomy kit creation toolAutomatic proposal of anatomyEditing tools with morphing and transformationAdvanced connector tools and shape editingHighly productive, easy to useVirtual Waxing tools – scaling & morphingDifferent output formats optimized with respect tomanufacturing solutionsFull anatomic veneer design for advanced smile line

CROWN & BRIDGE Module Features

CROWN & BRIDGE Module Features

Inlay, Onlay and Veneer Design

Special Considerations for CAD/CAM DentistryCAD/CAM technology is not a replacement for the accuracy and talent provided by a dentist or dental laboratory technician. Dentists must be precise in creating the initial tooth CAD/CAM technology, tend to be a more expensive restorative solution. However, even though the materials for CAD/CAM restorations might cost more, the expense incurred by the dental laboratory and/or the dentist may not be passed onto the patient.

Also, there is no additional fee or cost to have a restoration placed in one visit as opposed to two.

CONSIDERATIONS

preparation; both dentists and laboratory technicians must be accurate when taking the digital impression and drawing the restoration.

Equally important is the accuracy and skill with which they design a restoration, particularly since the fit of a restoration is critical to preventing future tooth damage. For example, an ill-fitted crown, veneer, inlay or onlay can leave space between the teeth, or between the tooth preparation and the restoration. This could lead to an increased risk of infection or disease.

When to Choose CAD/CAM Dentistry

It is important to note that not every tooth can be treated with a CAD/CAM restoration. Your dentist will determine if a CAD/CAM restoration is among the appropriate treatment options for your condition. Additionally, despite improvements in the esthetics of CAD/CAM materials, patients may find that some CAD/CAM restorations look too opaque and lack natural characterizations.

Depending on the type of restoration that's needed (such as inlays/onlays), your dentist may prefer conventional laboratory fabrication techniques that have a longer and more proven track record for accuracy of fit. Therefore, patients must discuss their particular situation and desires with their dentist, who will make the final treatment decision based on a thorough examination.