Osteoprotegerin expression in the peri-implant sulcus fluid after mechanical stimulations at different angles  
Fang Ming, Wang Zhi-ying, Yu Jin, Li Min, Jin Ding
Chinese Journal of Tissue Engineering Research . 2015, (8): 1255 -1260 .  DOI: 10.3969/j.issn.2095-4344.2015.08.020