| The purposes of this study were to implement a quantitative backscatter scanning electron microscopy based method to assess the effects of exogenous transforming growth factor-beta (TGF-beta) on mineralization of regenerated bone. Material from an experiment in which the proximal humeri of 10 male canines had been implanted bilaterally for four weeks with porous-coated implants in an 1ACUC approved protocol was used (Sumner, et al. 1995). One implant was treated with TGF-beta1, at a dose of 120 micrograms (n = 5) or a dose of 335 micrograms (n = 5), while the contralateral controls had no TGF-beta. Analysis of the SEM-based gray scale histograms indicated that TGF-beta1 treatment led to decreased mean and median calibrated graylevel values in the high dose group (p < 0.05), suggesting that this growth factor inhibited mineralization of the newly formed bone. |
