The invention discloses a partially elastic shaped body in the form of a negative image of a dental arch containing a matrix based on a gel containing an active substance or a system with a mineralizing effect as well as an application system for the treatment of teeth. The application system comprises an application dental splint that is well-suited for use on the upper and/or lower jaw, whereby the dental splint can accommodate at least one first three-dimensional shaped body that is adapted to the splint and contains a matrix, preferably the dental splint can be deformed by heat. The matrix of the at least one first and optionally further shaped body contains at least one active substance or a system with a mineralizing effect containing phosphates, calcium, and fluorides. The method for producing the application system and a kit comprising the application system are also a subject matter of the invention. According to the invention, the application system and kit are used for depositing apatite, in particular needle-shaped fluorapatite crystals. According to the invention, it is feasible to deposit more than or equal to 1 μm apatite, in particular fluorapatite, on tooth surfaces over one sleeping period or during the day in order to seal or brighten porous tooth surfaces.
