![]() ![]() None of the changes within the accuracy of the reference scanner can be divided into changes of the test object or scan errors. The limiting point with these new methods is the accuracy of the scanner, used to capture the test object. Also, volumetric changes can be measured 10. This enables the possibility of monitoring a specific area or displaying deformations in all three coordinate axes. With this superimposition, an evaluation of the surface changes at every scan point is possible. Linear measurements are possible, as well as superimpositions of models from different scan times. Here, the entire surface or volume is measured and displayed as a 3D object on the computer screen. Newer measuring methods include the optical or radiographic capturing of the entire surface of the test object 8,9. These methods are limited to only few measuring points and limited information of three-dimensional (3D) changes of the testing area. In many of these fields, current validation procedures are linear distance measurements with calipers or microscopes 6,7. However, other fields of dental treatment also benefit from a true and precise metrical outcome, to verify treatment success and evaluate new treatment strategies, e.g. soft and hard tissue augmentation, erosion and abrasion monitoring, periodontal treatments, and orthodontic treatments 4,5. This is why a highly accurate reproduction is needed, especially in the field of dental impressions and dental laboratory workflow. Fixed partial dentures and total prosthesis are especially critical for exact fitting at supporting structures like prepared teeth or implants 3. Replacing dental hard tissue needs an exact fitting prosthesis to ensure proper function and prevent further destroying the remaining tooth structure 1,2. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes.Īccuracy is a major interest in many fields in dental medicine. The reference scanner can be used to measure differences for a lot of dental research fields. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. Current dental impression methods showed much higher deviations (trueness: 20.4 ± 2.2 µm, precision: 12.5 ± 2.5 µm) than the internal scanning accuracy of the reference scanner. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 ± 1.1 µm for trueness and 1.6 ± 0.6 µm for precision in case of full arch scans. Also, different model materials were verified. A specific scanning protocol was tested to scan original tooth surface from dental impressions. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. ![]() The main interest is to verify impression methods as they serve as a base for dental restorations. Reference scanners are used in dental medicine to verify a lot of procedures.
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