Background: To compare structural features of the femoral bone of ovariectomized and non-ovariectomized rats after implantation of porous materials (TANTALUM, CONCELOC, TTM, ATLANT). Methods: Experiments were carried out on 56 white laboratory female rats aged 6 months. Rats were randomly assigned into groups: sham-operated control group (SH) or ovariectomy group (OVX). Four different commercial implant materials (TTM, CONCELOC, TANTALUM, ATLANT) were placed into the defects (diameter 2.5 mm, depth 3.0 mm) in the distal metaphysis of femurs. Rats were sacrificed 45 days after surgery. Histological study was performed and the percentage of the bone area (BA%) around the implant at a distance of 500 μm in the cancellous area was measured. Results: Formation of mature bone tissue of varying degrees around all of the implants was detected. In OVX rats cancellous bone defect zone was characterized by a high density of osteocytes on the surface. In the SH group, no differences in BA% among implant materials were found. In OVX rats, the BA% around ATLANT implants was 1.5time less (p = 0.002) than around TANTALUM. The BA% around the rest of the materials was not statistically different. Conclusions: Bone formation around the studied porous titanium and tantalum materials in the osteoporosis model was lower than in normal bone. There were differences in bone formation around the different materials in the osteoporosis model, while in the normal bone model, these differences were absent.

Bone tissue engineering strategy involves the 3D scaffolds and appropriate cell types promoting the replacement of the damaged area. In this work, we aimed to develop a fast and reliable clinically relevant protocol for engineering viable bone grafts, using cryopreserved adipose tissue‐derived mesenchymal stromal cells (MSCs) and composite 3D collagen‐nano‐hydroxyapatite (nanoHA) scaffolds. Xeno‐ and DMSO‐free cryopreserved MSCs were perfusion‐seeded into the biomimetic collagen/nanoHA scaffolds manufactured by cryotropic gelation and their osteoregenerative potential was assessed in vitro and in vivo. Cryopreserved MSCs retained the ability to homogenously repopulate the whole volume of the scaffolds during 7 days of post‐thaw culture. Moreover, the scaffold provided a suitable microenvironment for induced osteogenic differentiation of cells, confirmed by alkaline phosphatase activity and mineralization. Implantation of collagen‐nanoHA cryogels with cryopreserved MSCs accelerated woven bone tissue formation, maturation of bone trabeculae, and vascularization of femur defects in immunosuppressed rats compared to cell‐free collagen‐nanoHA scaffolds. The established combination of xeno‐free cell culture and cryopreservation techniques together with an appropriate scaffold design and cell repopulation approach accelerated the generation of viable bone grafts.

No abstract

The authors make a review of the current literature on the subject of bisphosphonateassociated osteonecrosis of the jaw bones. The modern theories about the occurrence of this complication resulting from bisphosphonate treatment of diseases characterized with high bone resorption are discussed. Modern understandings about the causes, risk factors and triggers for the occurrence of this disease are described. Attention is paid to the modern concepts of medication therapy and surgical treatment. A case of bisphosphonate-associated osteonecrosis of the maxilla with involvement of the maxillary sinus is reported. Surgical intervention comprising sequestrectomy, radical maxillary sinus surgery and plastic closure of the formed oroantral communication is described.

No abstract