Eclipse e600 stereomicroscope

One and three months after the operation, 5 rats of each group were sacrificed and the femurs were immersed in 4% neutral paraformaldehyde buffered solution for 2 days. Histological femoral tissue sections were acquired after decalcification, embedding and slicing. HE staining was conducted with Hematoxylin and Eosin Staining (HE) Kit (Beyotime, China) according to the user’s protocols. Histomorphometry was performed on transverse sections using Nikon ECLIPSE E600 stereomicroscope (Nikon, Tokyo, Japan), computer-coupled Nikon DXM1200 Digital Camera and NIS-Elements F2.20 image software.

All rats were sacrificed at 4 weeks following implantation. Specimens of tibiae were fixed in 10% neutral buffered formalin for 5 days, dehydrated in increasing gradients of alcohol, and embedded in methylmethacrylate resin. Undecalcified, ground 30-μm sections parallel to the long axis of the implant and vertical to the long axis of tibiae were obtained using an Exakt saw and grinding equipment (Exakt 300; Exact Advanced Technologies, GmbH, Norderstedt, Germany). The sections were stained with toluidine blue. Three sections of each specimen were examined at a magnification of ×100.
Histomorphometric analysis was performed with a semi-automated digitizing image analysis system, comprising a Nikon ECLIPSE E600 stereomicroscope, a computer-coupled Nikon DXM1200 Digital Camera and NIS-Elements F 2.20 image software (Nikon Corporation, Tokyo, Japan). Histomorphometric indices included the implant-bone contact rate (IBCR), defined as the direct implant-bone interface to total implant surface, and the ratio of calcified bone volume to total bone volume (BV/TV) within 2.0 mm of the axis of the implant. In each section, five equally spaced sites of each screw were measured and the mean value of all screws was accepted as the value of the index of the section (11 (link)).