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Background and aim: Human dental pulp stem cells (hDPSCs) constitute a promising alternative for central nervous system (CNS) cell therapy. Unlike other human stem cells, hDPSCs can be differentiated, without genetic modification, to neural cells that secrete neuroprotective factors. However, a better understanding of their real capacity to give rise to functional neurons and integrate into synaptic networks is still needed. For that, ex vivo differentiation protocols must be refined, especially to avoid the use of fetal animal serum. The aim of our study is to improve existing differentiation protocols of hDPSCs into neuron-like cells. Methods: We compared the effects of the (1) absence or presence of fetal serum during the initial expansion phase as a step prior to switching cultures to neurodifferentiation media. We (2) improved hDPSC neurodifferentiation by adding retinoic acid (RA) and potassium chloride (KCl) pulses for 21 or 60 days and characterized the results by immunofluorescence, digital morphometric analysis, RT-qPCR and electrophysiology. Results: We found that neural markers like Nestin, GFAP, S100β and p75NTR were expressed differently in neurodifferentiated hDPSC cultures depending on the presence or absence of serum during the initial cell expansion phase. In addition, hDPSCs previously grown as spheroids in serum-free medium exhibited in vitro expression of neuronal markers such as doublecortin (DCX), neuronal nuclear antigen (NeuN), Ankyrin-G and MAP2 after neurodifferentiation. Presynaptic vGLUT2, Synapsin-I, and excitatory glutamatergic and inhibitory GABAergic postsynaptic scaffold proteins and receptor subunits were also present in these neurodifferentiated hDPSCs. Treatment with KCl and RA increased the amount of both voltage-gated Na+ and K+ channel subunits in neurodifferentiated hDPSCs at the transcript level. Consistently, these cells displayed voltage-dependent K+ and TTX-sensitive Na+ currents as well as spontaneous electrophysiological activity and repetitive neuronal action potentials with a full baseline potential recovery. Conclusion: Our study demonstrates that hDPSCs can be differentiated to neuronal-like cells that display functional excitability and thus evidence the potential of these easily accessible human stem cells for nerve tissue engineering. These results highlight the importance of choosing an appropriate culture protocol to successfully neurodifferentiate hDPSCs. [ABSTRACT FROM AUTHOR]

The atrophic edentulous maxilla is demanding for dental implant placement because of extensive resorption of the alveolar ridge after teeth loss and, consequently, the proximity of the anatomical structures, nasal cavity, and maxillary sinus. Treatment options are short implants, guided bone regeneration, onlay grafts, Le Fort I osteotomy with interpositional bone grafting, distraction osteogenesis, or nasal floor elevation. Nasal floor elevation is a method of augmentation of premaxilla by raising the base of the nose. The aim of this case report is to evaluate the success of implants placed after nasal floor elevation. A 75-year-old female patient came to the Clinical Department of Oral Surgery, University Hospital Centre Zagreb, unsatisfied with her complete removable denture. Clinical and radiological examination revealed severe maxillary alveolar ridge atrophy. Nasal floor elevation was made under local anesthesia through aperture piriformis and lateral window in the distal part. After eight months, four implants were placed and, after period of osseointegration, a bar-retained implant overdenture was made. This case report shows that nasal floor augmentation can be considered among the surgical techniques to allow implant-supported rehabilitation of the atrophic anterior maxilla.

The etiopathogenesis of dental implant failure is multifactorial and may include numerous local and systemic factors, however, studies including both local and systemic factors are still lacking. Therefore, the aim of this study was to evaluate whether periodontal disease, oral hygiene index, i.e. bleeding on probing (BOP), full mouth plaque index (FMPI), smoking, systemic diseases, as well as implant characteristics (length and diameter) affect failure of implant-prosthodontic therapy. Data on 670 patients were retrieved in whom 1260 dental implants had been placed and followedup for at least five to ten years. Categorical data were analyzed by the χ2-test, whereas Mann-Whitney test was used for continuous variables (age, BOP and FMPI). The values of p

Mixing rabbit manure, pig or hen slurries and sewage sludge with paper sludge increases the potential of earthworms to transform the substrate into valuable compost. This mesophilic and aerobic hydrolysis process is an alternative treatment for waste produced by paper/pulp industry. Biotransformation is performed in two stages: destabilization and stabilization. Goals of the research program are discussed.