Abstract: Rotational medical or dental instrument (1), in particular a drill, a cutting tool, a file or the like. The instrument (1) has a shaft (5) for mounting the instrument (1) in a drive part and has an instrument part (2) which is connected to the shaft (5). Marks (6) are provided on the shaft (5) in a number corresponding to a maximum number of uses of the instrument (1). The marks (6) are provided in such a way that they can be removed. After each use of the instrument, one of the marks is removed so that the remaining number of marks (6) indicates how often the instrument (1) can still be used. After removing the last mark (6), the instrument (1) is spent, so that it can be discarded.

Abstract: A dental root canal instrument with a head part and an instrument part connected thereto. To lengthen the useful lifetime of the instrument, the instrument part has a coating of a wear-resistant material over at least a part of its length. The coating preferably has a certain color which is characteristic of the respective type of dental root canal instrument.

Abstract: A dental instrument with an instrument part (I) and a handle part (1, 1', 1") as well as a number of countable elements (2, 2', 4) which can be individually attached to or removed from the handle part (1, 1', 1"). With each use of the instrument, the dentist is able to remove or attach one element from/to the handle part (1, 1', 1"). The number of countable elements (2, 2', 4) on the handle (1, 1', 1") provides the dentist with an indication of the number of completed uses made with the instrument, so that it can be disposed of before it is subject to stress failure during use.