Mineralized and Osteoid Tissue from Dental Pulp Stem Cells on Micro-arc Oxidation Titanium in vitro

The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface.DPSCs were challenged at MAO and smooth titanium surface separately for different durations,and the bone marrow mesenchymal stem cells(BMSCs) served as the positive controls.The osteogenic capacity of DPSCs on MAO titanium surface was assessed by using scanning electron microscopy,energy dispersive spectroscopy,biochemical tests and real-time quantitative PCR.Data showed that DPSCs differentiated into osteoblasts and expressed bone morphogenetic genes on MAO titanium surface.The results of this study revealed that DPSCs had good potential to generate mineralized tissue on MAO titanium plates.The differential potential of DPSCs may be regulated by MAO titanium surface.The osteogenesis potential of DPSCs on the MAO titanium was similar with BMSCs.

Osteoporosis as A Source of Tissue Mineralization Research on Osteoporosis Therapy and Dissolution of Arterial Mineralization

Based on research conducted by the author in the last thirty-five years, this article presents the physicochemical mechanisms of the osteoporosis process, transport of substances created as its result, and the phenomena of tissue mineralization resulting from osteoporosis. Examination of bones, joint cartilage, arteries, veins, parts of heart, thyroid, salivary glands, various tumors and others was conducted with the use of biological and polarizing microscopy, SEM, EDS, ASA, IR, Raman spectroscopy, and X-ray diffraction. Several devices of the same kind, e.g. different types of SEM, were used. Specimens used for examination were obtained from post-surgery and post rnortem materials. Examination of human bones focused on their mineralization and demineralization （osteoporosis）. Examination of the mineralization of other tissues was conducted in terms of the ageing of human body. Obtained results show that the process of osteoporosis leads not just to mechanical degradation of bones, but through the transport of ions （mainly Ca and P）, it also causes mineralization of soft tissue. Such mineralization occurs in mineralization centers that have been classified in regard to genetics. Tissue mineralization in its first stage is latent and consists of including atoms, mainly Ca and P, into the biological structures of compounds that build the tissues. Latent mineralization may evolve into the next stage--apparent mineralization. Both types of mineralization cause many health issues and may lead to death. This article also presents initial results of research on dissolution of aortic mineralization.

Meeting report:a hard look at the state of enamel research

The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines （ENAMEL） Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National institute of Dental and Craniofacial Research （NIDCR）. Discussion topics included model organisms, stem cells/cell lines, and tissues/3D cell culture/organoids. Scientists from a number of disciplines, representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.

Distribution of mechanical strain in equine distal metacarpal subchondral bone:A microCT-based finite element model

Microdamage accumulation and adaptation of subchondral bone subjected to intensive cyclic loading are important processes associated with catastrophic bone failure,and joint degeneration in athletic humans and racehorses.At the tissue-level,they lead to a spatial variation in bone tissue mineral density(TMD)which affects the response of the bone to mechanical load.Quantifying the spatial distribution of mechanical load within the subchondral bone is critical for understanding the mechanism of the joint failure.Previously,a gradient of TMD and mechanical properties has been reported under unconfined compression in osteochondral plugs.In the present study,we used micro computed tomography(μCT)-based finite element(FE)models of cartilage-bone to investigate the gradient of strain in the subchondral bone(SCB)from the third metacarpal(MC3)condyle of racehorses under simulated in situ compression.Non-destructive mechanical testing of specimens under high-rate compression provided the apparent-level modulus of SCB.FE models were analysed using unconfined and confined boundary conditions.Unconfined FE-predicted apparent-level gradient of modulus across the SCB thickness correlated well with the experimental results(R^(2)=0.72,p<0.05).The highest strain occurred in the most superficial SCB(0.5–2.5 mm deep to the cartilage-bone interface)under the simulated in-situ compression through articular cartilage.The findings of this study provide an estimation for the spatial distribution of mechanical strain within SCB in-situ in the presence of heterogeneous bone tissue which is commonly observed in joints subjected to intensive cyclic loading.