Abstract: A filling material pin (1) is provided made from a flexible material and is used for filling a root canal (6) of a tooth. The flexible material is memory material, which expands upon heating to the tooth or body temperature in the form of a volume change. The exterior of the filling material pin (1) is profiled at least across the length thereof that is effective in the use position such that regions having both larger and smaller cross-sections alternate in the axial direction, which can be achieved in a particularly useful and simple manner by a helical, threaded, or worm shape of the profiling, which simultaneously pushes an added cement or filling material more effectively and deeper into the canal (6) upon rotating the filling material pin (1) inserted into the root canal (6), thus allowing air contained therein to escape.