Figure 3. Tartrate-resistant acid phosphate (TRAP) staining of osteoclasts (OCLs) treated with or without CSCs or ALD. (a) Representative images of each group. (-) CTL, BMMs without RANKL/LPS treatment; (+) CTL, OCLs (BMMs treated with RANKL/LPS); BIOD, OCLs treated with Biodentine conditioned media; PMTA, OCLs treated with ProRoot MTA conditioned media; ALD, OCLs treated with alendronate. (b) Quantification of TRAP-positive osteoclasts. Number of TRAP-positive cells was significantly higher in (+) CTL (P<0.05), while no significant differences were observed between BIOD, PMTA, and ALD (P>0.05). Different asterisks (* and **) means that they were significantly different each other. BMMs=bone marrow macrophages; CSCs=calcium silicate-based cements; LPS=lipopolysaccharide; OCLs=osteoclasts; RANKL=receptor activator of NF-κB; TRAP=tartrate-resistant acid phosphate.