Objective:To evaluate the micro-push-out bond strengths of prefabricated glass fiber posts with poly-dopamine functionalized to root dentin using resin cements, contrasted with silane treatment. Methods:In the study, 30 glass fiber posts were randomly divided into 3 groups ( 10 posts in each group) for different surface treatments. Group 1, treated with poly-dopa; Group 2, treated with silane coupling agent for 60s;Group 3, no surface treatment (Control group). The 30 extracted human, single-rooted teeth were endodontically treated and a 9 mm post space was prepared in each tooth with post drills provided by the manufacturer. Following post cementation, the specimens were stored in distilled water at 37 ℃ for 7 days. The micro-push-out bond strengths were tested using a universal testing machine (0. 5 mm/min), and the failure modes were examined with a stereomicroscope. The data of the three groups were statistically analyzed using the one-way ANOVA test(α= 0. 05). Results:The bond strengths were (7. 909 ± 1. 987) MPa for Group 1, (5. 906 ± 0. 620) MPa for Group 2, and 4. 678 ± 0. 910 MPa for Group 3 . The bond strength of poly-dopamine group was significantly higher than that of the silane group (P<0. 05). Conclusion: Contrasted with silane treatment, surface poly-dopamine functionaliza-tion was confirmed to be a more reliable method for improving the bond strength of resin luting agents to fiber posts.

The high neurogenic potential of dental and oral-derived stem cells due to their embryonic neural crest origin, coupled with their ready accessibility and easy isolation from clinical waste, make these ideal cell sources for neuroregeneration therapy. Nevertheless, these cells also have high propensity to differentiate into the osteo-odontogenic lineage. One strategy to enhance neurogenesis of these cells may be to recapitulate the natural physiological electrical microenvironment of neural tissues via electroactive or electroconductive tissue engineering scaffolds. Nevertheless, to date, there had been hardly any such studies on these cells. Most relevant scientific information comes from neurogenesis of other mesenchymal stem/stromal cell lineages (particularly bone marrow and adipose tissue) cultured on electroactive and electroconductive scaffolds, which will therefore be the focus of this review. Although there are larger number of similar studies on neural cell lines (i.e. PC12), neural stem/progenitor cells, and pluripotent stem cells, the scientific data from such studies are much less relevant and less translatable to dental and oral-derived stem cells, which are of the mesenchymal lineage. Much extrapolation work is needed to validate that electroactive and electroconductive scaffolds can indeed promote neurogenesis of dental and oral-derived stem cells, which would thus facilitate clinical applications in neuroregeneration therapy.
Cell Differentiation ; Mesenchymal Stem Cells/metabolism* ; Neural Stem Cells/metabolism* ; Neurogenesis ; Tissue Scaffolds

Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.