Abstract: The invention relates to a film clamping element, in particular for carrying out dental treatment in the mouth area of a patient, comprising a vestibular ring (14) and a lip ring (12), between which and optionally beyond which a film (16) extends. The film is held in a stretched manner by the rings, and the film (16) and the rings are elastically deformable, in particular the film and the rings can be pressed together into a substantially oval shape. The invention is characterized in that the vestibular ring (14) has a recess on at least one circumferential point, the width of said recess being greater than the width of a frenulum and smaller than the radius of the vestibular ring (14).

Abstract: The invention relates to an injection device with an injector (12) and with a cartridge (14) that contains dental material and can be inserted into or attached onto the injector (12), said injector (12) having a piston (28) which, as it enters the cartridge (14), is intended to press the dental material out of the cartridge (14), said cartridge (14) having a collar (16) which is intended to bear on a holding projection (20) of the injector (12). The holding projection (20) is formed on a guide element (36) of the injector (12). The guide element (36) has a sensor (50) for a code (52) which is applied to the cartridge (14), and the injector (12) has a display at an area spaced apart from the holding projection (20), particularly on the top face, or obliquely on the top face, in the rear area of the injector (12).