Evaluating Peri-Implant Bone Microstructure

To evaluate microstructure of peri-implant bone more precisely, samples were randomly selected for scanning using X-ray microscopy (ZEISS Xradia Versa 520, USA) with the following parameters: an X-ray source voltage of 80 kV, power of 7 W, and pixel size of 10 μm. Then the three-dimensional images of implants and peri-implant bone were reconstructed by XMReconstructor (Carl Zeiss, USA). To evaluate the inner zone of peri-implant bone response, the region of interest (ROI) of peri-implant bone in each tomography was selected from middle 30 layers of implant body and was defined as a rectangle extending 500 μm from the implant surface, with the entire length of the implant screw [40 (link)]. Next, the bone morphometry indices were measured from three-dimensional images at ROIs in the compressive and tensile sides, including BV/TV, Tb.N, Tb.Sp, Tb.Th and SMI, which were calculated using CTAn software (Skyscan, Belgium) [41 (link)].