socket preservation with completely demineralized dentin graft followed by delayed implant placement after 4 months

After 4 months of socket preservation and just before implant placement, a trephine bur will be used to collect a core of bone from the preserved socket. Bone will be examined histologically to evaluate the quality and quantity of the formed bone.

Briefly, the specimens were fixed with 4% paraformaldehyde in 0.1M PBS (pH 7.4) and decalcified in 0.5M EDTA (pH 7.8). After decalcification, each specimen will be processed and embedded in paraffin, and transverse serial sections of 5 μm thickness will be prepared. The sections will be stained with hematoxylin and eosin (H&E), Masson's Trichrome (MT) (Cat # HT15, Sigma Aldrich) and immunohistochemical staining with osteocalcin antibody polyclonal osteocalcin (OCN);diagnostic biosystems), histological examination will be carried out using an Olympus BX-51 optical microscope (Olympus Co., Tokyo, Japan).

Microscopic images of the surgical sites will be taken by randomly selecting four areas of the center portion of the defect at 100× magnification. Then, using 16 images of each group, the ratio of newly formed bone to the entire defect area in the slide images will be calculated in trichrome and osteocalcin-stained images using the Intel® Core I7® based computer using VideoTest Morphology® software (Russia) with a specific built-in routine for % area, measurement.

Bone density will be evaluated using Cone Beam Computed Tomography (CBCT) that will be made immediately after socket preservation, at 4 months after preservation (just before implant placement), and after 12 months from implant loading.