3D Digital Dental Scanning Of Teeth May Soon Replace Plaster Models

Cadent iTero

Using current technology, dental technicians typically make dentures, removable partial dentures, and dental crowns using a bite impression. The silicone template for this plaster model is made by the dentist, in a procedure which is unpleasant for the patient. In the future, a 3-D  dental scanning provide the teeth contours – without a plaster dental model.

When a toothache makes a visit to the dentist unavoidable this often marks the start of a time-consuming treatment marathon for the patient. If the tooth cannot be saved and a dental prosthesis is necessary, the dentist first has to make a silicone dental impression for the dental laboratory. The patient is sent home with a provisional repair and dental technicians set to work on modeling a plaster impression.

The intricate and laborious route from bite impression and plaster mold in the laboratory is now becoming a thing of the past.  The three-dimensional coordinates of the tooth surface can now be determined on the basis of measurements taken in the patient’s mouth and digital dental impressions fabricated.

Dr. Peter Kühmstedt, an expert team at the Fraunhofer institute developed an 3D digital scanner which scans the oral cavity and captures three-dimensional data of the teeth using camera optics. A complete picture of the individual tooth is created from several data records. After an all-round measurement, it is even possible to represent the complete jaw arch as a virtual computer image. The measurement conditions in the confined oral cavity are, however, unfavorable.

To obtain precise results, the scientists use fringe projections in which a projector shines strips of light on the tooth area to be measured. From the phase-shifted images the evaluation software determines the geometric contour data of the tooth. Two camera optics provide the sensor chip with image information from different measurement perspectives. After the pixel-precise comparison of various camera images, the evaluation program recognizes any image faults and removes them from the complete image.

It is problematic if the patient moves while the images are being taken in the oral cavity. The scientists have therefore made sure that the process takes place quickly. “The image sequence for each measurement position is captured in less than 200 milliseconds,” explains Kühmstedt.

Cadent iTero is one of the first systems with powered by proprietary 3D scanner software, enabling the dentist to take a powder-free digital scan of the patient’s teeth and bite, make any necessary adjustments in real-time, and then transmit the file via a wireless Internet connection to a Cadent-partnering laboratory for further processing. From there, the digital file is transmitted to Cadent where a precision milled model is created and shipped to the laboratory within 48 hours. The laboratory also can import the iTero STL file into its lab-based CAD/CAM milling system for direct production of copings and full coverage CAD/CAM restorations. With significant benefits such as increased patient satisfaction, improved clinical outcomes, and enhanced office efficiencies, iTero is making an impression…125,000 of them and counting.

Straumann, a global leader in regenerative, restorative, and replacement dentistry will begin marketing Cadent’s iTero’s digital impression system as of February 1st, 2011.

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