A micro-computed tomographic (uCT) analysis of bone healing subsequent to graft (tri calcium phosphate/TCP) placement in the maxillary sinus prior to dental endosteal implant placement was the focus of the current study. Ten trephined rod shaped human bone cores were obtained three months after the placement of particulate graft material. Using the uCT, samples were evaluated at 6 and 20 μm resolutions. The images exhibited regions of different grey scale (GL) magnitudes for bone and graft allowing a differentiation and quantification of the two sample regions. The GL threshold magnitudes at 20 μm resolution were determined to be less than 235 for organic and fluid, 235-450 for bone, 400-600 for bone and graft, and 600 and above for the graft material. The graft material was integrated with the bone showing the osteoconductivity of the TCP material, the mean bone volume was 25.50 (11.28) ranging from 5.66 to 37.9 and the mean graft volume was 0.42 (0.37) ranging from 0.01 to 1.17. The mean graft to bone volume ratio was 0.015 (0.01) with a range from 0.002 to 0.024. The structural data and observations from two- and three-dimensional images provided a valuable assessment of the graft distribution, its relation to modeling bone and also the anatomy of the healing bone. Thus this study demonstrated the capability to uniquely evaluate the status of healing bone associated with this TCP grafting biomaterial with opportunities for subsequent correlations with histomorphometrical studies and clinical outcomes of these type implant treatments. © 2008 Wiley Periodicals, Inc.