Changes of maxillary central incisor and alveolar bone in Class II Division 2 nonextraction treatment with a fixed appliance or clear aligner: A pilot cone-beam computed tomography study.

INTRODUCTION: This retrospective clinical study investigated the clinical changes of maxillary central incisor and alveolar bone in Class II Division 2 nonextraction treatment with fixed appliances or clear aligners on the basis of cone-beam computed tomography. METHODS: Fifty-nine Chinese Han patients with similar demographic characteristics were collected from a conventional bracket group, a self-ligating bracket group, and a clear aligner group. All measurements about root resorption and alveolar bone thickness on the cone-beam computed tomography images were tested. Changes between pretreatment and posttreatment were evaluated by paired-sample t test. The variation among the 3 groups was compared by 1-way analysis of variance. RESULTS: The resistance center of the maxillary central incisor showed upward or forward movement, and the axial inclination was increased in 3 groups (P <0.0001). Root volume loss in the clear aligner group (23.68 ± 4.82 mm3) was significantly less than that in the fixed appliances group (28.24 ± 6.44 mm3 in the conventional bracket group, 28.17 ± 6.07 mm3 in the self-ligating bracket group) (P <0.05). All 3 groups showed a significant decrease in palatal alveolar bone and total bone thickness at all 3 levels at posttreatment. In contrast, labial bone thickness significantly increased except for crestal level l. Among the 3 groups, the clear aligner group had a prominent increase in labial bone thickness at the apical level (P = 0.0235). CONCLUSIONS: Clear aligner treatment for Class II Division 2 malocclusions could effectively reduce the incidence of fenestration and root resorption. Our findings will be beneficial to comprehensively understand the effectiveness of different appliances for Class II Division 2 malocclusions treatment.

Dynamic Change in Oral Microbiota of Children With Cleft Lip and Palate After Alveolar Bone Grafting.

To investigate the longitudinal influence of alveolar bone grafting on the oral microbiota of children with cleft lip and palate (CLP).Twenty-eight children with nonsyndromic CLP were recruited and underwent secondary alveolar bone grafting at the first time. Unstimulated saliva and plaque samples were collected from the subjects preoperatively and at 2 days, 1 month, and 3 months postoperatively. The v3-v4 hypervariable regions of the 16S rRNA gene from bacterial DNA were sequenced using the Illumina MiSeq sequencing platform.The alpha diversity of the saliva and plaque microbiota was significantly decreased at 2 days postoperatively and then increased at 1 and 3 months postoperatively. The saliva and plaque microbiota compositions at 2 days postoperatively differed from those at the other time points, and the microbiota compositions at 1 and 3 months postoperatively showed a gradual shift toward the preoperative composition. The saliva, but not plaque, microbiota composition 3 months postoperatively was similar to that preoperatively.The effect of secondary alveolar bone grafting on the plaque microbiota in children with CLP lasted longer than the saliva microbiota. Alveolar bone grafting altered the saliva microbiota in children with CLP within 3 months postoperatively.

Effect of VEGFC on lymph flow and inflammation-induced alveolar bone loss.

The lymphatic system plays a crucial role in the maintenance of tissue fluid homeostasis and the immunological response to inflammation. The effects of lymphatic drainage dysfunction on periodontitis have not been well studied. Here we show that lymphatic vessel endothelial receptor 1 (LYVE1)+ /podoplanin (PDPN)+ lymphatic vessels (LVs) are increased in the periodontal tissues, with accumulation close to the alveolar bone surface, in two murine periodontitis models: rheumatoid arthritis (RA)-associated periodontitis and ligature-induced periodontitis. Further, PDPN+ /alpha-smooth muscle actin (αSMA)- lymphatic capillaries are increased, whereas PDPN+ /αSMA+ collecting LVs are decreased significantly in the inflamed periodontal tissues. Both mouse models of periodontitis have delayed lymph flow in periodontal tissues, increased TRAP-positive osteoclasts, and significant alveolar bone loss. Importantly, the local administration of adeno-associated virus for vascular endothelial growth factor C, the major growth factor that promotes lymphangiogenesis, increases the area and number of PDPN+ /αSMA+ collecting LVs, promotes local lymphatic drainage, and reduces alveolar bone loss in both models of periodontitis. Lastly, LYVE1+ /αSMA- lymphatic capillaries are increased, whereas LYVE1+ /αSMA+ collecting LVs are decreased significantly in gingival tissues of patients with chronic periodontitis compared with those of clinically healthy controls. Thus, our findings reveal an important role of local lymphatic drainage in periodontal inflammation-mediated alveolar bone loss. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Identification of novel susceptibility loci for non-syndromic cleft lip with or without cleft palate.

Although several genome-wide association studies (GWAS) of non-syndromic cleft lip with or without cleft palate (NSCL/P) have been reported, more novel association signals are remained to be exploited. Here, we performed an in-depth analysis of our previously published Chinese GWAS cohort study with replication in an extra dbGaP case-parent trios and another in-house Nanjing cohort, and finally identified five novel significant association signals (rs11119445: 3' of SERTAD4, P = 6.44 × 10-14 ; rs227227 and rs12561877: intron of SYT14, P = 5.02 × 10-13 and 2.80 × 10-11 , respectively; rs643118: intron of TRAF3IP3, P = 4.45 × 10-6 ; rs2095293: intron of NR6A1, P = 2.98 × 10-5 ). The mean (standard deviation) of the weighted genetic risk score (wGRS) from these SNPs was 1.83 (0.65) for NSCL/P cases and 1.58 (0.68) for controls, respectively (P = 2.67 × 10-16 ). Rs643118 was identified as a shared susceptible factor of NSCL/P among Asians and Europeans, while rs227227 may contribute to the risk of NSCL/P as well as NSCPO. In addition, sertad4 knockdown zebrafish models resulted in down-regulation of sox2 and caused oedema around the heart and mandibular deficiency, compared with control embryos. Taken together, this study has improved our understanding of the genetic susceptibility to NSCL/P and provided further clues to its aetiology in the Chinese population.

ROCK-TAZ signaling axis regulates mechanical tension-induced osteogenic differentiation of rat cranial sagittal suture mesenchymal stem cells.

Mechanical force across sutures is able to promote suture osteogenesis. Orthodontic clinics often use this biological characteristic of sutures to treat congenital cranio-maxillofacial malformations. However, the underlying mechanisms still remain poorly understood. Craniofacial sutures provide a special growth source and support primary sites of osteogenesis. Here, we isolated rat sagittal suture cells (rSAGs), which had mesenchymal stem cell characteristics and differentiating abilities. Cells were then subjected to mechanical tension (5% elongation, 0.5 Hz; sinusoidal waveforms) showing that mechanical tension could enhance osteogenic differentiation but hardly affect proliferation of rSAGs. Besides, mechanical tension could increase Rho-associated kinase (ROCK) expression and enhance transcriptional coactivator with PDZ-binding motif (TAZ) nuclear translocation. Inhibiting ROCK expression could suppress tension-induced osteogenesis and block tension-induced upregulation of nuclear TAZ. In addition, our results indicated that TAZ had direct combination sites with runt-related transcription factor 2 (Runx2) in rSAGs, and knock-downed TAZ simultaneously decreased the expression of Runx2 no matter with or without mechanical tension. In summary, our findings demonstrated that the multipotency of rSAGs in vitro could give rise to early osteogenic differentiation under mechanical tension, which was mediated by ROCK-TAZ signal axis.

Osteocytes promote osteoclastogenesis via autophagy-mediated RANKL secretion under mechanical compressive force.

Osteocytes sense extracellular mechanical stimuli and transduce them into biochemical signals to regulate bone remodeling. The function is also evidenced in orthodontic tooth movement. But the underlying mechanisms haven't been clarified. Autophagy is an evolutionarily conserved cellular catabolic process which affects cellular secretory capabilities. We hypothesized that mechanical force activated osteocyte autophagy through TFE3-related signaling and further promoted osteocyte-mediated osteoclastogenesis. In the present study, we demonstrated that osteocyte autophagy was activated under mechanical compressive force using murine orthodontic tooth movement model since the number of LC3B-positive osteocytes increased by 3-fold in the compression side. In addition, both in vitro mechanical compression and chemical autophagy agonist increased the secretion of RANKL in osteocytes by 3-fold and 4-fold respectively, which is a crucial cytokine for osteoclastogenesis. Lastly, conditioned medium collected from compressed osteocytes promoted the development of osteoclasts. These results suggest that osteocytes could promote osteoclastogenesis via autophagy-mediated RANKL secretion under mechanical compressive force. Our research might provide evidence for exploring methods to accelerate tooth movement in clinic.

Biodegradable Zwitterion/PLGA Scaffold Enables Robust Healing of Rat Calvarial Defects with Ultralow Dose of rhBMP-2.

Designing smart scaffolds to reduce administration dosage under the premise of functional healing of bone defects to avoid the severe side effects associated with BMP-2 treatments is one of the essential goals in bone tissue engineering. Here, we report a novel biodegradable PLGA/PSBMA composite as the scaffold for bone tissue engineering. The introduction of zwitterionic PSBMA components can alter the intrinsic burst degradation behavior of PLGA and enable a sustained degradation of the scaffold over the time. The PLGA/PSBMA scaffold can sequester rhBMP-2 and enable a sustained release of the sequestered rhBMP-2 with preserved bioactivity. Furthermore, PLGA/PSBMA scaffolds were able to guide robust healing of critical-sized nonunion calvarial defects (5 mm) at an ultralow dose of 400 ng/scaffold, at which level successful healing of critical-sized bone defects has never been reported. These findings indicate the PLGA/PSBMA scaffolds as novel high-efficiency rhBMP-2 delivery vehicles for bone tissue engineering, and the concept of utilizing the material, which is capable of maintaining the bioactivity of the proteins in the preparation of scaffolds, may open a new avenue for the design of smart scaffolds/vehicles for high-efficiency protein/bioactive drug therapies.

Synthesis of a molecularly imprinted polymer using MOF-74(Ni) as matrix for selective recognition of lysozyme.

A molecularly imprinted polymer and metal organic framework were combined to prepare protein imprinted material. MOF-74(Ni) was used as a matrix to prepare surface-imprinted material with lysozyme as a template and polydopamine as an imprinting polymer. MOF-74(Ni) not only provides a large surface area (150.0 m2/g) to modify the polymer layer with more recognition sites (Wt (Ni) = 42.24%), but also facilitates the immobilization of lysozyme by using the chelation between Ni2+ of the MOF-74(Ni) and protein. The thin polydopamine layer (10 nm) of the molecularly imprinted material (named MOF@PDA-MIP) enables surface imprinting. Benefiting from the thin polymer layer, MOF@PDA-MIP reached adsorption equilibrium within 10 min. The maximum adsorption capacity reaches 313.5 mg/g with the highest imprinting factor (IF) of 7.8. The specific recognition sites can distinguish target lysozyme from other proteins such as egg albumin (OVA), bovine serum albumin (BSA) and ribonuclease A (RNase A). The material was successfully applied to separation of lysozyme from egg white. Graphical abstract.

Non-syndromic cleft lip with or without palate susceptible loci is associated with tooth agenesis.

OBJECTIVE: Non-syndromic tooth agenesis (NSTA) may share common genetic factors with non-syndromic cleft lip with or without cleft palate (NSCL/P). Single-nucleotide polymorphisms (SNPs) were associated with individual's susceptibility to these anomalies. We selected five NSCL/P-associated SNPs from our previous genome-wide association study (GWAS) to test for the associations with NSTA. MATERIALS AND METHODS: A total of 677 NSTA cases and 1,144 healthy controls were recruited in this case-control study. Five genome-wide NSCL/P-associated SNPs (rs2235371, rs7078160, rs8049367, rs4791774, and rs13041247) were genotyped by TaqMan platform and evaluated for the associations with NSTA using plink software. RESULTS: No significant associations between these SNPs and risk of NSTA were observed in the overall analysis and subgroup analysis with the number of missing teeth. However, in the subgroup analysis by tooth position, rs8049367 was nominally associated with mandibular premolar agenesis (Dominant model: ORdom  = 0.66, 95% CIdom  = 0.47-0.93, pdom  = 0.016; Heterozygote model: ORhet  = 0.60, 95% CIhet  = 0.41-0.88, Phet  = 0.008). Rs4791774 showed a nominal association with congenitally missing maxillary canine (Dominant model: ORdom  = 0.53, 95% CIdom  = 0.28-0.98, pdom  = 0.041; Heterozygote model: ORhet  = 0.50, 95% CIhet  = 0.26-0.97, Phet  = 0.041) and premolar (Additive model: OR = 0.59, 95% CI = 0.36-0.96, p = 0.035). CONCLUSION: This study showed that NSCL/P susceptible loci rs8049367 and rs4791774 were probably associated with the risk of NSTA.

Preparation and evaluation of open-tubular capillary column combining a metal-organic framework and a brush-shaped polymer for liquid chromatography.

In this work, an open-tubular capillary liquid-phase column was prepared by modifying chain polymer on the inner surface of capillary and chemical bonding of metal organic frameworks, NH2 -UiO-66, to the brushes of chain polymer (poly(glycidyl methacrylate)). Besides advantages of facial preparation and good permeability, the chain polymer effectively increases the modification amount of NH2 -UiO-66 nanoparticles to increase the phase ratio of open-tubular capillary column and enhance the interactions with analytes. The results of scanning electron microscope energy-dispersive X-ray spectra indicated that NH2 -UiO-66 nanoparticles were successfully bonded to the chain polymer. Because of the hydrophobic interaction and hydrogen bonding interaction between the analytes and the ligand of NH2 -UiO-66, different analytes were well separated on the NH2 -UiO-66-modified poly(glycidyl methacrylate) capillary (1.12 m × 25 µm id × 365 µm od) with the high absolute column efficiency reaching 121 477 plates, benefiting from an open-tubular column and low mass transfer resistance provided by polymer brush and metal-organic framework crystal. The relative standard deviations of the retention time for run-to-run, day-to-day, and column-to-column (n = 3) runs are below 4.28%, exhibiting good repeatability. Finally, the column was successfully applied to separation of flavonoids in licorice.

Mechanical Stretch-Induced ATP Release from Osteocytes Promotes Osteogenesis of Bone Marrow Mesenchymal Stem Cells.

BACKGROUND: Mandibular distraction osteogenesis (MDO) is a highly effective method for bone regeneration, commonly employed in treating craniofacial defects and deformities. Osteocytes sense mechanical forces in the pericellular space, relay external stimuli to biochemical changes, and send signals to other effector cells, including bone marrow mesenchymal stem cells (BM-MSCs), to regulate bone resorption and formation. Piezo1 potentially affects the secretion signal molecules of bone cells under mechanical stretch. The primary aim of this study was to enhance our comprehension of the molecular biology underlying this therapeutic approach and to identify specific signaling molecules that facilitate bone formation in response to stretch forces. METHODS: Mechanical stretching was applied to negative controls and Piezo1 knockdown osteocyte-like MLO-Y4 cells. Alkaline phosphatase and Alizarin Red S staining were used to survey the osteogenic potential of BM-MSCs. The production and secretion content of adenosine triphosphate (ATP) was measured using ATP content determination analysis. Pathway-related and osteo-specific genes and proteins were evaluated using real-time polymerase chain reaction (RT-PCR), Western blots, and immunofluorescence. Mitochondrial organization was examined with a transmission electron microscope. RESULTS: The conditioned medium of stretch-exposed MLO-Y4s significantly upregulated osteogenesis-related indicators of BM-MSCs (p < 0.001). The upregulation of BM-MSC osteogenesis was associated with ATP release from osteocytes. Mechanically induced calcium transfer and transcriptional coactivator with PDZ-binding motif (TAZ) nuclear translocation mediated by Piezo1 could promote mitochondrial fission and ATP release. Osteocytes detected stretch forces through Piezo1, triggering calcium influx, TAZ nuclear translocation, and ATP production. CONCLUSIONS: The stretch stimulation of Piezo1 induces calcium influx, which in turn promotes calcium-related TAZ nuclear translocation, changes in mitochondrial dynamics, and the release of ATP in osteocytes. This signaling cascade leads to an up-regulation in the osteogenic capacity of BM-MSCs. Mitochondrial energy metabolism of mechanosensitive protein Piezo1-dependent and ATP release may provide a new effective intervention method for mechanically related bone remodeling.

[Preparation technology comparison and performance evaluation of different protein A affinity chromatographic materials].

Protein A affinity chromatographic materials are widely used in clinical medicine and biomedicine because of their specific interactions with immunoglobulin G (IgG). Both the characteristics of the matrix, such as its structure and morphology, and the surface modification method contribute to the affinity properties of the packing materials. The specific, orderly, and oriented immobilization of protein A can reduce its steric hindrance with the matrix and preserve its bioactive sites. In this study, four types of affinity chromatographic materials were obtained using agarose and polyglycidyl methacrylate (PGMA) spheres as substrates, and multifunctional epoxy and maleimide groups were used to fix protein A. The effects of the ethylenediamine concentration, reaction pH, buffer concentration, and other conditions on the coupling efficiency of protein A and adsorption performance of IgG were evaluated. Multifunctional epoxy materials were prepared by converting part of the epoxy groups of the agarose and PGMA matrices into amino groups using 0.2 and 1.6 mol/L ethylenediamine, respectively. Protein A was coupled to the multifunctional epoxy materials using 5 mmol/L borate buffer (pH 8) as the reaction solution. When protein A was immobilized on the substrates by maleimide groups, the agarose and PGMA substrates were activated with 25% (v/v) ethylenediamine for 16 h to convert all epoxy groups into amino groups. The maleimide materials were then converted into amino-modified materials by adding 3 mg/mL 3-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) dissolved in dimethyl sulfoxide (DMSO) and then suspended in 5 mmol/L borate buffer (pH 8). The maleimide groups reacted specifically with the C-terminal of the sulfhydryl group of recombinant protein A to achieve highly selective fixation on both the agarose and PGMA substrates. The adsorption performance of the affinity materials for IgG was improved by optimizing the bonding conditions of protein A, such as the matrix type, matrix particle size, and protein A content, and the adsorption properties of each affinity material for IgG were determined. The column pressure of the protein A affinity materials prepared using agarose or PGMA as the matrix via the maleimide method was subsequently evaluated at different flow rates. The affinity materials prepared with PGMA as the matrix exhibited superior mechanical strength compared with the materials prepared with agarose. Moreover, an excellent linear relationship between the flow rate and column pressure of 80 mL/min was observed for this affinity material. Subsequently, the effect of the particle size of the PGMA matrix on the binding capacity of IgG was investigated. Under the same protein A content, the dynamic binding capacity of the affinity materials on the PGMA matrix was higher when the particle size was 44-88 µm than when other particle sizes were used. The properties of the affinity materials prepared using the multifunctional epoxy and maleimide-modified materials were compared by synthesizing affinity materials with different protein A coupling amounts of 1, 2, 4, 6, 8, and 10 mg/mL. The dynamic and static binding capacities of each material for bovine IgG were then determined. The prepared affinity material was packed into a chromatographic column to purify IgG from bovine colostrum. Although all materials showed specific adsorption selectivity for IgG, the affinity material prepared by immobilizing protein A on the PGMA matrix with maleimide showed significantly better performance and achieved a higher dynamic binding capacity at a lower protein grafting amount. When the protein grafting amount was 15.71 mg/mL, the dynamic binding capacity of bovine IgG was 32.23 mg/mL, and the dynamic binding capacity of human IgG reached 54.41 mg/mL. After 160 cycles of alkali treatment, the dynamic binding capacity of the material reached 94.6% of the initial value, indicating its good stability. The developed method is appropriate for the production of protein A affinity chromatographic materials and shows great potential in the fields of protein immobilization and immunoadsorption material synthesis.

An open tubular capillary electrochromatography column with porous inner surface for protein separation.

An open tubular capillary electrochromatography (OTCEC) column using sole porogen to form porous inner surface has been developed. The porous layer was coated on the capillary inner wall by in situ polymerization in the presence of porogen. The results show that the columns using 1-propanol as sole porogen are appropriate for protein separation. It has higher separation efficiency than the column with the usual coporogen due to much more micropores and mesopores on the porous surface and a higher specific surface area. In addition, the sensitivity of the prepared OTCEC column was improved greatly compared with the dynamically coated capillary with polyvinylpyrrolidone.

MMP-9 -1562C>T contributes to periodontitis susceptibility.

AIM: The study was conducted to explore the potential association of Matrix metalloproteinases (MMP)-9 -1562C>T with susceptibility to periodontitis. MATERIALS AND METHODS: Electronic literature searches of PubMed, EMBASE and EBSCO databases were performed. Fixed-effects or random-effects models were used to calculate the pooled odds ratios (ORs) for four genetic comparisons. RESULTS: Seven eligible studies with a total of 628 cases and 689 controls were recruited in the pooled analysis. We found MMP-9 -1562C>T contributed to decreased risk of chronic periodontitis. Furthermore, the polymorphism was associated with modified risk of periodontitis among Caucasian populations. CONCLUSIONS: This study indicated that MP-9 -1562C>T might be involved in the development of periodontitis. A replication of our results in independent large analysis populations is necessary to give evidence to our observation.

Three-dimensional evaluation of the mandibular condyle in adults with various skeletal patterns.

Objective: Morphometric and morphological evaluation of the mandibular condyle in adults and to identify its correlation with skeletal malocclusion patterns. Methods: Cone-beam computed tomography scans of 135 adult patients were used in this study and classified into groups according to four criteria: (1) sex (male and female); (2) sagittal skeletal discrepancy (Class I, Class II, and Class III); (3) vertical skeletal discrepancy (hyperdivergent, normodivergent, and hypodivergent); and age (group 1 ≤ 20 years, 21 ≤ group 2 < 30, and group 3 ≥ 30 years). The morphometrical variables were mandibular condyle height and width, and the morphological variable was the mandibular condyle shape in coronal and sagittal sections. Three-dimensional standard tessellation language files were created using itk-snap (open-source software), and measurements were performed using Meshmixer (open-source software). Results: The mandibular condyle height was significantly greater (p < 0.05) in patients with class III malocclusion than in those with class I or II malocclusion; the mandibular condyle width was not significantly different among different sexes, age groups, and sagittal and vertical malocclusions. There were no statistical associations between various mandibular condyle shapes and the sexes, age groups, and skeletal malocclusions. Conclusions: The condylar height was greatest in patients with class III malocclusion. The condylar height and width were greater among males than in females. The mandibular condyle shapes observed in sagittal and coronal sections did not affect the skeletal malocclusion patterns.

Preparation and evaluation of ultra-long open-tubular capillary columns modified with zeolitic imidazolate framework-8 incorporated polymeric porous layer for liquid chromatography.

An ultra-long (5 m) open tubular capillary liquid chromatographic column was prepared by incorporating Metal Organic Framework (MOF), zeolitic imidazolate framework-8 (ZIF-8), directly into polymer coating, which was synthesized by the copolymerization of 4-vinylbenzyl chloride and divinylbenzene, on the capillary inner surface. The prepared ZIF-8 incorporate polymeric open tubular capillary column (denoted as ZIF-8-p(VBC/DVB) OTCC) was evaluated with thiourea, alkylbenzenes and polycyclic aromatic hydrocarbons as probe molecules. The results showed that the ultra-long column achieved absolute column efficiency of 130,000 plates for thiourea, and the incorporation of ZIF-8 effectively improved the chromatography performance of the OTCC. Baseline separation of aromatic compounds and position isomers was achieved based on multiple interactions provided by the zeolitic imidazolate framework and polymer, including hydrophobic interaction, π-π stacking interaction and the coordination effect. The RSD values (run-to-run, day-to-day, column-to-column, n = 3) of retention time of phenylenediamine isomers and propylbenzene isomers were less than 0.7%, 1.2% and 4.0% respectively, suggesting excellent repeatability. Finally, the prepared ZIF-8-p(VBC/DVB) OTCC was applied to the separation of hydroxyacetophenone isomers with satisfied results.

Development and assessment of an online virtual orthodontic curriculum.

INTRODUCTION: Due to break space and time limits, an entirely new online curriculum of orthodontic education with online evaluation system has been structured and developed in the dental school, based on virtual reality simulation. CURRICULUM: At Nanjing Medical University, a new online orthodontic curriculum with programmatic assessment process was constructed and implemented based on competency-based education (CBE). It was consisted of the online orthodontic theoretical lectures based on the National Open Online Course "Orthodontics," the online journal club via the online "flipped classroom," and the online orthodontic pre-clinical training via the virtual learning network platform. In order to evaluate this curriculum, 94 Year 4 dental students took part to complete the online orthodontic curriculum. The mean total score of all the students was 91.99, and the element scores of the online theoretical lectures, journal club, virtual pre-clinical training, and online final examination were respectively 96.83, 79.49, 96.00, and 87.02, which showed a good performance. According to the student feedback toward this curriculum via the online questionnaire, nearly 98% of the students showed agreement or strong agreement that the online orthodontic curriculum has enhanced their orthodontic theoretical understanding and orthodontic practical ability. CONCLUSION: As a student-centered CBE, this online orthodontic curriculum with online evaluation system could provide both orthodontic theory and practice teaching for all the dental students at all times and places based on the online virtual mode, which enriched learners' critical thinking, problem solving, and assessment skills.

In situ mineralized PLGA/zwitterionic hydrogel composite scaffold enables high-efficiency rhBMP-2 release for critical-sized bone healing.

Osteoconductive and osteoinductive scaffolds are highly desirable for functional restoration of large bone defects. Here, we report an in situ mineralized poly(lactic-co-glycolic acid)/poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide hydrogel (PLGA/PSBMA) scaffold as a novel high-efficiency carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) for bone tissue regeneration. By virtue of the oppositely charged structure, the zwitterionic PSBMA component is able to template well-integrated dense mineralization of calcium phosphate throughout the PLGA/PSBMA scaffold. The high affinity between rhBMP-2 and the mineralized matrix, combined with the capability of the zwitterionic hydrogel to sequester and to enable sustained release of ionic proteins, endows the mineralized PLGA/PSBMA scaffolds with high-efficiency sustained release of rhBMP-2 (only 1.7% release within 35 days), thus enabling robust healing of critical-sized (5 mm) nonunion calvarial defects in rats at an ultralow dosage of rhBMP-2 (150 ng per scaffold), at which level successful healing of critical-sized bone defects has never been reported. These findings show that the mineralized PLGA/PSBMA scaffold is promising for bone defect repair.

Zwitterionic/phosphonate copolymer coatings endow excellent antifouling properties and robust re-mineralization ability of dentine substrates.

Inhibition of biofilm formation and induction of the re-mineralization of damaged dental tissues are two major strategies to combat dental hypersensitivity (DH). However, single component synthetic materials normally cannot fulfil these two functions during the repairing of damaged dental tissues. Here, we report zwitterionic phosphorylcholine based polymers to be a new type of dual functional coating for the repairing of DH. Zwitterionic/phosphonate copolymers, p(DEMMP-co-MPC), bearing varied zwitterionic contents (95 and 75 mol%) were prepared through conventional radical copolymerization. 1H NMR spectroscopy clearly indicated the precise preparation of the copolymers. The copolymers can be easily coated on dentine substrates based on the high affinity between the phosphonate group and the calcium phosphate minerals of the dentine substrates, as evidenced by XPS and water contact angle measurements. Antifouling evaluations indicated that zwitterionic coating can efficiently inhibit protein adsorption (BSA, egg white, and milk, by 85%) and bacterial adhesion (by 97.1%) on dentine substrates. Furthermore, in vitro and in vivo experiments consistently indicated that the zwitterionic coating could not only induce the robust re-mineralization of dentine surfaces, but also template the extensive re-mineralization of dentine tubules to a similar level of pristine dentine. Both the antifouling properties and the re-mineralization potency are positively correlated with the content of zwitterionic pMPC in the coating copolymer. These findings may provide the zwitterionic phosphorylcholine based materials to be a promising candidate to treat dental hypersensitivity and other related dental diseases.