Apexification of immature permanent teeth with calcium hydroxide paste 
Nie Er-min, Lu Jie, Jiang Rui, Zhang Chun-yuan, Zeng Jin-di, Tan Ji-zhou
Chinese Journal of Tissue Engineering Research . 2015, (34): 5438 -5442 .  DOI: 10.3969/j.issn.2095-4344.2015.34.006