A, Inhibition of ALP activity of calvarial osteoblasts when treated with different conditioned media (CM). B, Parallel cell proliferation assay of osteoblasts treated with different CM. Control, standard media; GFCM, Gingival fibroblast CM; COCM, Calvarial osteoblast CM. C, Inhibition of ROS cell ALP activity with dilution of GFCM. GFCM diluted with standard media. D, Normalized ROS cell ALP activity treated with heat‐treated (1‐10 minutes) GFCM. Control: standard media. Heat treatment—GFCM placed in boiling water for 1, 5 or 10 minutes. E, Normalized ROS cell ALP activity of treated with molecular weight fractionated GFCM. > indicates concentrates, < filtrates. ALP activity adjusted for cell number in all experiments. Minimum of three replicates per experiment. Data shown as mean ± SD. Representative data from three independent experiments are shown. Significant differences shown as *(P < 0.05). Significance tested using one‐way ANOVA with Bonferroni post‐tests