DIN EN ISO 10271:2011-10

In the standard, test methods for the corrosion of metallic materials for fixed and removable dental prosthetics are specified. ISO 10271 was developed as a result of worldwide demand for standard test methods to determine acceptability of metallic materials for oral restorations in relation to corrosion. The testing of the corrosion behaviour of metallic materials in dentistry is complicated by the diversity of the materials themselves, their applications and the environment to which they are exposed. Variations occur between devices and the device itself changes during the exposure time. The type of corrosion behaviour or effect can vary within the exposure time. Accordingly, it is not possible to specify a single test capable of covering all situations, nor is it a practical proposition to define a test for each situation. The standard, therefore, gives detailed procedures for test methods that have been found to be of merit as evidenced by considerable use. This second edition differs from the first edition by the addition of two new test methods. To supplement the existing static immersion test, a static immersion test with periodic analysis has been added. A major reason for the addition of this test is that the rate of corrosion of most dental metallic materials varies over time. Thus, the aim of the static immersion test with periodic analysis is to provide information on this variation in the corrosion of a dental metallic material. A clause to interpret the long-term corrosion behaviour of the tested alloys (that is, steady, decreasing, increasing) was not included as part of the static immersion test with periodic analysis. Instead, data are provided in a graphic illustration without the intention of interpreting the shape of the resulting curve. It is intended that ISO/TC 106/SC 2/WG 12 monitors the use of the static immersion test with periodic analysis through appropriate working groups of ISO/TC 106 and undertakes necessary modifications to the document in a future revision. To supplement the sulfide tarnish test (cyclic immersion), a sulfide tarnish test (static immersion) has also been added to this second edition of draft standard DIN EN ISO 10271. This test has been used successfully for many years to evaluate the corrosion of silver alloys. In addition, an informative annex (Annex A) is provided that sets out a procedure for each element of the test system such that a consistent approach can be taken for the development of further test methods. Equally, it is recognized that any element can represent only the current recommendation. It is, however, unlikely that modifications in the future will change the framework. It is not the purpose of this International Standard to propose corrosion test methods for specific applications or to set limits as precise as those in the standard relating to the type of product and its application. The International Standard has been prepared by ISO/TC 106/SC 2/WG 12 "Corrosion test methods" (secretariat: ANSI), together with CEN/TC 55 "Dentistry" (secretariat: DIN). Working Committee NA 014-00-17 AA "Metalle" ("Metallic materials") of Working Group NA 014-00-17-02 AK "Korrosion" ("Corrosion") of NADENT is responsible at DIN.