FIG. 3.

Effects of injections of live or heat-killed bacteria on osteoclast numbers in mouse calvaria. Organisms were injected once daily for 6 days at the doses indicated. The mice were sacrificed 24 h later, and osteoclast numbers in decalcified calvarial sections were counted. Values are means ± standard errors of means. ∗, Significantly different from mean value for vehicle-treated (RTF) mice (P < 0.05). #, Dose response significantly different from that to P. gingivalis (P < 0.01). +, Dose response significantly different from that to C. rectus (P < 0.001). $, Significantly different from mean value for mice treated with live F. nucleatum bacteria (P < 0.01).