Long non-coding RNA XIST regulates chondrogenic differentiation of synovium-derived mesenchymal stem cells from temporomandibular joint via miR-27b-3p/ADAMTS-5 axis.

OBJECTIVE: Temporomandibular joint osteoarthritis (TMJOA) is a common degenerative disease in jaw joint, accompanied by articular cartilage destruction. Differentiation of stem cells to cartilage has important therapeutic implications in TMJ cartilage repair. Previous studies revealed that lncRNA XIST participated in various biological processes. However, the effect of XIST on chondrogenic differentiation of synovium-derived mesenchymal stem cells (SMSCs) remains unclear. Our study aimed to investigate the function of XIST in chondrogenic differentiation of human SMSCs from TMJ. METHODS: Alcian blue staining was performed to determine proteoglycan in SMSCs. qPCR, western blotting and immunofluorescence assays were allowed to assess sex determining region Y-box 9 (SOX9), Collagen type II alpha 1 chain (COL2A1) and Aggrecan (ACAN) expression. The direct interaction between miR-27b-3p and XIST or ADAMTS-5 was confirmed by dual luciferase reporter assay or RNA immunoprecipitation (RIP) assay. RESULTS: XIST was remarkably down-regulated in chondrogenic differentiation of SMSCs. Functional analysis demonstrated that XIST silencing promoted chondrogenic differentiation of SMSCs. Dual luciferase reporter and RIP assays identified that XIST acted as a sponge for miR-27b-3p. Moreover, XIST regulated ADAMTS-5 expression by directly binding miR-27b-3p. More importantly, miR-27b-3p/ADAMTS-5 rescued the effects of XIST on chondrogenic differentiation of SMSCs. CONCLUSION: The results suggest that XIST modulates SMSCs chondrogenic differentiation via the miR-27b-3p/ADAMTS-5 axis, which provides new targets for TMJOA treatment.

Maxillary impacted canine replacing a central incisor with root resorption: Multidisciplinary treatment in a preadolescent patient.

Maxillary canines are often impacted, which can result in tooth disorders and adversely affect occlusal and facial development. The case report describes complete bilateral impaction of maxillary canines and significant root resorption of a central incisor. The multidisciplinary approach is the optimal strategy for addressing impacted maxillary canines.

Evaluation of osteogenic and antibacterial properties of strontium/silver-containing porous TiO2 coatings prepared by micro-arc oxidation.

Ti and Ti alloys are bioinert materials and two frequent problems associated with them are bacterial infection and lack of osteogenic potential for rapid bone integration. To overcome the problems, the present study incorporated strontium (Sr) and silver (Ag) simultaneously into porous TiO2 coatings through a single-step technique, micro-arc oxidation (MAO). Incorporation of Sr and Ag brought no significant changes to coating micromorphology and physicochemical properties, but endowed TiO2 coatings with both strong antibacterial activity and osteogenic ability. Antibacterial activity increased with Ag contents in the coatings. When Ag content reached 0.58 wt%, the coating showed both excellent short-term (100.0%) and long-term (77.6%) antibacterial activities. Sr/Ag-containing coatings with 18.23 wt% Sr and 0.58 wt% Ag also presented good cytocompatibility for preosteoblast adhesion and proliferation, and promoted preosteoblast osteogenic differentiation both short-termly and long-termly. However, higher Ag content (1.29 wt%) showed toxic effects to preosteoblasts. In summary, MAO is a simple and effective way to incorporate Sr and Ag into porous TiO2 coatings and Sr/Ag-containing TiO2 coating with 18.5 wt% Sr and 0.58 wt% Ag has both good osteogenic activity and strong antibacterial capability short-termly and long-termly. Therefore, such coatings are valuable for clinical application to strengthen osseointegration and long-term high quality use of titanum implants.

Effectiveness of strontium-doped brushite, bovine-derived hydroxyapatite and synthetic hydroxyapatite in rabbit sinus augmentation with simultaneous implant installation.

Various bone substitutes have been applied in sinus augmentation (SA) to overcome insufficient bone height at the posterior maxilla region caused by pneumatized sinus and severe alveolar bone resorption after teeth loss. However, their effectiveness in SA needs to be further elucidated. In this study, strontium-doped brushite (Sr-DCPD), a new bone substitute, together with bovine-derived hydroxyapatite (bHA) and synthetic hydroxyapatite (sHA) was used in rabbit maxillary SA with simultaneous implant installation. The sinus space-keeping capacity, resorption rate, osteoconductivity, and mechanical properties of regenerated bone, were evaluated by micro-computed tomography (CT), histological analysis, and mechanical testing. Sr-DCPD exhibited the best osteoconductivity and new bone formation (<4 weeks), but its final bone regeneration and removal torque of implants at week 12 were the lowest, mainly due to its poor space-keeping capacity and fast resorption. bHA exhibited the best space-keeping capacity and slowest resorption rate, but relative lower final bone volume and mechanical properties, while sHA showed good space-keeping capacity, slower resorption rate, and the best final bone formation and mechanical properties. sHA was most effective for SA and bHA was also an acceptable bone substitute; however, Sr-DCPD was least effective and not suitable in SA by itself.

[The influence of different treating agents on the shear bond strength between zirconia and orthodontic brackets].

PURPOSE: To compare the effect of different treating agents on the shear bond strength (SBS) between zirconia and orthodontic brackets. METHODS: Fifty zirconia specimens were randomly divided into 5 groups(n=10), and treated with sandblasted and 37% phosphoric acid.Group A was control sample without any treatment; Group B was treated with silane coupling agent; Group C was treated with silane coupling agent and SE Bond; Group D were treated with Z-Prime(TM) Plus; Group E were treated with Z-Prime(TM) Plus+SE Bond. The upper incisor brackets were bonded to each specimen using 3M Transbond light-cured resin adhesive. Each specimen was put into 37°C water, and SBS tests were performed after 24 hours. Then statistical analysis was carried out regarding to the adhesive residual index(ARI) of the zirconia oxide surface after removing the brackets. The surface of zirconia in each group was scanned with scanning electron microscope after surface treatment, and the surface morphology changes were observed, infrared spectra analysis was conducted on zirconia and treating agents. SPSS 17.0 software package was utilized for statistical analysis. RESULTS: The mean SBS in each group was as follows: group A (3.12±0.84) MPa; group B (1.92±0.83) MPa; group C (5.26±0.80) MPa; group D (6.54±0.98) MPa; group E (9.47±2.11) MPa. Significant difference existed between each group (P<0.05), group A and B had lower ARI, while ARI in group E was highest. Group D and E achieved effective bond strength. CONCLUSIONS: Using Z-Prime(TM) Plus can achieve effective bond strength, which is lower than Z-Prime(TM) Plus combined with SE Bond. It's suggested to use Z-Prime(TM) Plus combined with SE Bond to achieve higher SBS for orthodontic treatment.

[Literature analysis of current bilingual teaching on stomatology in China].

PURPOSE: To investigate the current status and problems of bilingual teaching on stomatology in China. METHODS: Three database, including CNKI, Wanfang database and VIP were used to retrieve the articles of bilingual teaching on stomatology from January 2001 to December 2012. RESULTS: Fifty articles were included in this study and the following items, publishing time, foundation support, journals, authors and author affiliation, the course, teaching effects, research classification and main components of the articles were analyzed. The problems remained were also discussed. CONCLUSIONS: The level of current bilingual teaching on stomatology in China is low and great efforts are needed to make it better. Supported by Research Fund of Hebei United University(Z201333).