DIN EN ISO 12836:2013-01

The opportunity of computer-aided manufacture of dental prosthesis has revolutionized dentistry in the last century. As new development this includes the digital dental impression, either directly by the dentist in the mouth of the patient or indirectly by the dental technician, for example, of a dental mould. The attainable accuracy is decisive in comparison with the previous analogue dental impression by means of impression materials. Regarding conventional dental impression several potential sources of error exist in a process chain which might under certain circumstances have a negative effect on the quality of the end product. This includes the possible warping of the dental impression by a limited shelf life, partial or extensive detachment of the impression material from the spoon, a too low dimensional stability of the impression material, disinfection of the precision impression in the disinfection bath, the transport to the dental laboratory at various climatic conditions. In comparison intraoral digital dental impression provides direct access to the so-called digital workflow. This standard specifies test methods for the assessment of the accuracy of digitizing devices for computer-aided design/computer-aided manufacturing (CAD/CAM) systems for indirect dental restorations. Accuracy, repeatability and reproducibility of devices for digitalization of intra- and extra-oral surfaces for hard and soft tissues and components of dental implant systems and all models thereof shall be determined in order to verify their effectiveness. This test method is not applicable to digitization by radiographic methods (X-ray) and by magnetic resonance imaging methods. This standard describes the methods for testing the accuracy of dental digitizing devices for verification of their quality, reliability and repeatability. This standard is based on the premise that only the matched point cloud and the resulting Standard Tesselation Language surface (STL surface) thereof be regarded as the product of scanning the physical object. For testing the digitalization performance, three specimens (two dental and one technical) are used: 1) specimen in order to simulate inlay-shaped cavities; 2) multi-unit specimen, consisting of two full coverage dies with a centre-to-centre distance of 30 mm, being designed to simulate digitizing a 4-unit-bridge; 3) a sphere, the measurement of which is limited to the hemisphere lying above the horizontal plane. The International Standard has been prepared by ISO/TC 106/WG 9 "Dental CAD/CAM systems" (secretariat: DIN), in collaboration with CEN/TC 55 "Dentistry" (secretariat: DIN). The responsible committee at DIN is Working Committee NA 014-00-06 AA "CAD/CAM-Systeme" ("CAD/CAM systems") of NADENT.