Intraoral scan
An intraoral scan is a digital impression of the patient's mouth. This means that dentures , inlays , occlusal splints or devices for orthodontic treatment can be made without conventional impressions using impression materials.
execution
A small camera is used to scan the rows of teeth inside the mouth and record them in digital data. The surfaces in the patient's mouth are optically recorded without contact, so-called point clouds (universal ASCII format) are generated and displayed on the monitor as a three-dimensional model. The various intraoral scanners differ in their recording technology. Common methods are coaxial probing ( confocal principle ) and triangulation . The 3D surface is described in STL format (Surface Tesselation Language) - a file format in which the surface is represented by a triangular network. The accuracy of the surface rendering depends on the resolution of the triangular mesh.
The different functionality of the scanners means that the scan result is significantly influenced by the correct scan path according to the current status. The scan path means that the intraoral camera is guided over the surfaces in a specific movement pattern. Intraoral exposure reaches its limit when blood and sulcus fluid prevent the photo-optical impression. Only areas that can be optically captured by the camera can be reproduced.
Dental production
The data are transmitted to the dental laboratory and form the database for the CAD / CAM design of the dental prosthesis. In the laboratory, dentures can be milled fully automatically from various materials, for example zirconium (correct: zirconium (IV) oxide) or a chromium-cobalt-molybdenum alloy (CKM), whether only as a framework that is then veneered or completely . It can also be used to produce aligners for orthodontic treatment.
In almost every dental laboratory nowadays, traditionally produced plaster models , i.e. models that are produced after an analog impression, are digitally scanned and only then processed. It is therefore advantageous to skip this flawed intermediate step of making analog impressions and models and to record the data in the mouth. Application-sensitive work steps such as the impression taking, setting time, disinfection , shipping and model production are no longer necessary. Undercuts, pillar divergences or the distance to the antagonist can be reworked and scanned immediately. If the scan quality is unsatisfactory, the data acquisition can be repeated without any problems. There is no need to prepare a new impression tray, as with the conventional method, and no new impression material has to be mixed. Digital model data sets do not take up any space for archiving. The digital acquisition also has advantages for the patient, since a conventional impression often causes a gag reflex. The purchase of an intraoral scanner is, however, associated with not inconsiderable costs. The purchase price ranges between € 15,000 and € 45,000.
Professional law aspects
In a position paper of the German Dental Association (BZÄK) it says:
"The German Dental Association has determined that the digital impression of the patient's oral cavity by intraoral scan is the practice of dentistry in accordance with Section 1, Paragraph 3 of the Dentistry Act. ... Correct execution requires dental expertise, as a "layman" cannot judge whether all relevant areas have been adequately covered. The intraoral scan may therefore only be performed by a dentist or under the supervision and on the instructions of a dentist. "
The intraoral scan is therefore one of the services that can be delegated, but only to persons capable of delegation, as described in the delegation framework for dental assistants of the BZÄK .
Jurisprudence
The Düsseldorf Regional Court decided that delegation to other people, such as dental technicians or even pharmacists, is permitted. There it says:
“Intraoral scans in the form that is the subject of the proceedings through the production of video recordings are not a service reserved for dentists according to the Dentistry Act (ZHG); these do not even achieve the quality of the services that can be delegated according to Paragraph 1, Paragraph 5 of the ZHG, such as, in particular, the production of x-rays or situation impressions. There is no risk to health that is comparable to the radiation exposure in X-ray exposures, nor does work in the patient's oral cavity that are comparable to the production of situation impressions. Rather, they are comparable to technical measurements in advance. "
The decisive factor is that, in the case of a scan made by dental assistants , pharmacists or dental technicians, the dentist himself decides at a later point in time about the usability and use of the image material. The Higher Regional Court of Düsseldorf fully confirmed this view in the subsequent instance with its judgment of May 19, 2020.
literature
- M. Zimmermann, M. Kern, intraoral scanner - a current overview , ceramics group. Retrieved July 6, 2020.
- Ingo Baresel, Intraoral scan: Conventional was yesterday , Dental-Magazin, August 30, 2016. Accessed July 6, 2020.
Individual evidence
- ↑ Intraoral Scanners in Practice , Henry Schein Magazine, February 26, 2019. Accessed July 6, 2020.
- ↑ Digital impression of the oral cavity by intraoral scan, German Dental Association , January 29, 2020. Retrieved July 6, 2020.
- ↑ Delegation framework of the German Dental Association for Dental Assistants , Federal Dental Association , September 16, 2009. Accessed July 6, 2020.
- ^ LG Düsseldorf, judgment of October 2, 2019, Az .: 12 O 184/19
- ↑ Intraoral scans - who is allowed, who is not? , DZW. Retrieved July 6, 2020.