A root canal filling material for a tooth extraction or tooth non-extraction process can be used clinically because of its easy availability and can efficiently enhance dental tissue regeneration; a method for regenerating dental tissue using the filling material is also provided. A root canal filling material 200 including mesenchymal stem cells 220 excluding dental pulp stem cells, which are inserted into the apical side of a root canal subjected to pulp extirpation or to root canal enlargement and cleaning of an infected root canal and including an extracellular matrix 210 is provided, and a method for regenerating dental tissue, through a tooth extracting or tooth non-extracting process, including a step of injecting the root canal filling material into the apical side of a root canal of a non-extracted tooth subjected to pulp extirpation or to root canal enlargement and cleaning of an infected root canal is provided.