Skyscan 1272 system

Sample scans were performed on a SkyScan 1272 system (Bruker microCT, Kontich, Belgium) operated at 45 keV source voltage and 201 μA current with the following parameters: image pixel resolution of 25.0 μm, rotations by 0.3° steps over a total of 180°, averaging 4 frames. A stack of about 628 projection raw images (1008 × 1008 pixels) was obtained. The scan duration for each sample was 45 min.

Tibiae were fixed in 10% formalin and scanned using a SkyScan 1272 system (Bruker, Kontich, Belgium), as previously described [28 (link)]. All measurements followed standard guidelines [29 (link)]. Next, 3 µm decalcified wax tissue sections were assessed for osteoclasts and osteoblasts as previously described [30 (link)].

The internal microporous organization and potential structural defects in PLA-CD 5% scaffolds were investigated through Micro-CT acquisitions, utilizing a Bruker Skyscan 1272 system (Großweikersdorf, Austria). The measurements were conducted at a voltage of 40 kV and a current of 250 µA, with a rotation step of 0.2° and a resolution of 4.5 µm.

The high resolution Skyscan 1272 system (Bruker) was used for µCT analysis with the following parameters: 60 kV as source voltage, 83 μA as source current, 0.5 mm aluminum filter, 5 µm pixel size, 0.4° rotation step. Data reconstruction was performed with NRecon (Bruker) and data analysis with CTAn (Bruker). Trabecular bone parameters were defined in a volume of interest (VOI) between 1 and 2.5 mm below the growth plate, whereas cortical bone parameters were quantified in a VOI between 2.5 to 3 mm below the growth plate. Analysis was performed according to the guidelines of the American Society for Bone and Mineral Research (20 (link)). 3D models were constructed with CTvox software (Bruker).

Formation of new bone in defect areas was evaluated by Micro-CT (Bruker Skyscan 1272 system, Kontich, Belgium). The parameter is set to 55 kV and 114 m A with a thickness of 0.048 mm per slice in medium-resolution mode, 1024 reconstruction matrix, and 200 ms integration time. These images and parameters of trabecular bone with a distance of 1 mm proximal from the end of the growth plate in femoral metaphysis were compared between the Sham group and OVX group to confirm the osteoporosis rat model. For evaluation of bone formation in the defect area, a 1.5-mm-diameter area in the center of each bone defect was selected as the volume of interest (VOI). After 3D reconstruction, bone mineral density (BMD), bone mineral content (BMC), bone volume fraction (BV/TV), trabecular number(Tb.N), trabecular thickness (Tb.Th), and trabecular separation(Tb.Sp) were automatically determined for identification of osteoporosis model, while BMD, BV/TV, Tb. N, Tb. Th, Tb. Sp, and the mean connective density (Conn. D) in VOI regions were used to evaluate new bone formation, using a protocol provided by the manufacturer of the Micro-CT scanner as previously described [24 (link), 25 (link)].

Tomographic images from left hemi-mandibles (n = 5/group) were acquired using a SkyScan 1272 system (Bruker microCT; Kontich, Belgium) [70 kVp and 142 μA; 0.5 mm aluminum filter; 9 μm isotropic voxel; 1100 ms exposure time, 2 frames averaging, and 180° rotation (0.5° rotation step)], and three-dimensionally reconstructed (NRecon software; v1.6; Bruker microCT). Alveolar bone loss was evaluated in the first molar region, a region of interest (ROI) was standardized from defined anatomical points (upper limit: furcation roof; lower limit: proximal root apex; distal limit: 2nd molar proximal root; proximal limit: 1st molar proximal root, and vestibular and lingual limits: limits of the alveolar bone). A volume of interest (VOI) was automatically delimited by the bone edges and the tooth volume exclusion. The bone percentage (BV/TV), trabecular number (Tb.N), thickness (Tb.Th), and separation (Tb.Sp) were analyzed [25 (link)].