Objective:To investigate the application effect of population/patient, intervention/exposure, comparison/control, and outcome (PICO) principles based on evidence-based medicine in case reports of residents in operative dentistry and endodontics.Methods:A total of 56 residents in Department of Conservative Dentistry and Endodontics in Hospital of Stomatology, Sun Yat-sen University, were selected and randomly divided into experimental group and control group, with 28 residents in each group. The residents in the experimental group were guided by the teachers to apply PICO principles in preparing case reports, and those in the control group were guided by the teachers to prepare traditional case reports. The two groups were compared in terms of the language expression of case reports, the completeness of case records, the rationality and advancement of the diagnosis and treatment regimen, and the logicality and scientificity of discussion, and a questionnaire survey was performed for both groups. SPSS 24.0 software was used to perform the descriptive statistical analysis, the t-test, and the chi-square test. Results:The experimental group had a significantly higher mean score of case report than the control group in department examination [(89.25±3.24) vs. (86.32±3.55), t=3.23, P=0.002], especially the score of the logicality and scientificity of discussion [(27.25±0.16) vs. (23.78±0.36), t=8.77, P<0.001]. The questionnaire survey showed that the experimental group had a significant increase in the frequency of participating in case reports ( P=0.035). Conclusions:The application of PICO principles can enhance the overall quality of case reports by residents and improve their enthusiasm in participating in case reports in department of operative dentistry and endodontics.

Objective:To investigate the effect of holistic thinking training mode on establishing clinical holistic thinking in endodontic practice teaching for students.Methods:Holistic thinking training mode was applied among Batch 2013 (group A, n=174) and Batch 2014 (group B, n=92) students of Guanghua School of Stomatology, Sun Yat-sen University. The teaching results were evaluated by the scores before and after the training and questionnaire, and by comparing their scores with those of Batch 2012 (group C, n=88) students. SPSS 20.0 was used to conduct one-way ANOVA and t test. Results:Compared the scores of students in group A with group B, the total scores before and after the training and the scores of "case report" were not statistically different, but the scores of holistic thinking were significantly improved after the training. Compared with the scores of students in group C, the total scores after the training and the "case report" scores of group A and B were significantly higher. The results of the questionnaire showed that 87.9%(153/174) of the students thought the training mode was conducive to the establishment of holistic thinking, but 77.6%(135/174) thought further improvement was needed in terms of content and time allocation.Conclusion:Holistic thinking training mode has a positive effect on the endodontic practice teaching, and is worth promoting in other departments after further improvement.

Objective: To evaluate the application effect of smart classroom teaching mode in undergraduate teaching of endodontics. Methods: Through micro-lecture and massive open online course which were closely integrated with clinical practice and frontier advances, we build a new smart classroom teaching mode of endodontics relying on information technology such as the medical education cloud APP platform. The mode was applied to the undergraduate teaching of grade 2017 (110 students) and grade 2018 (107 students) in 2020 and 2021 respectively (experimental group). The theoretical examination was conducted for the grade 2016 (control group, 111 students applied traditional teaching methods) in 2019, and for two experimental grades in 2020 and 2021 respectively. A questionnaire survey was conducted for the 2018 undergraduates to investigate the experience of the smart classroom teaching mode, and the application effect of the smart classroom teaching mode was evaluated by comparing the offline theoretical test scores of grades 2016, 2017 and 2018. Results: The results of the questionnaire showed that students in grade 2018 recognized the overall form of smart classroom teaching mode, and 75.2% (79/105) of the students satisfied with the teaching process, considering that it could enhance learning interest and enthusiasm, improve self-learning ability, facilitate the understanding and memory of knowledge points, as well as increase the extension and expansion of professional knowledge. Thirty-seven point one percent (39/105) of the students thought that smart classroom teaching mode was not conducive to the interaction between teachers and students and couldn't improve learning efficiency. Comparing the final theoretical examination scores of students in three years, it was found that the average scores of 2021 (78.79±9.88) and 2020 (76.45±8.33) were significantly higher than that of 2019 (67.67±10.58) (t=6.77, P<0.001; t=8.51, P<0.001). The average score in 2021 was higher than that in 2020, although the difference was not significant (t=1.79, P=0.223). Conclusions: The application of smart classroom mode improved the teaching effect of endodontics, which is worthy of further promotion to provide a positive reference in improving the educating effects of oral medicine.
Humans ; Learning ; Endodontics ; Students ; Dental Care ; Surveys and Questionnaires

Composite resin filling material is the first choice for tooth direct bonding restoration. Its good performance can meet the requirements of clinical tooth repair treatment. It is used to restore the structure, aesthetic and function of defected teeth with a way of minimally invasive intervention. To further improve its clinical efficacy, the fundamental strategy is to ameliorate the limitation of material properties. Based on the summary of current research progress, this article focuses on the property of improved composite resin material, and the progress of developing novel resin material including antibacterial composite resin, bioactive remineralizing resin as well as self-healing resin, so as to provide innovative ideas for the future research of new composite resin filling materials.

OBJECTIVE: To investigate whether cell preservation solution can prolong the survival time of leukemia cells and increase the survival rate, so as to improve the detection rate of central nervous system leukemia. METHODS: Kasumi cells were added into cerebrospinal fluid (CSF) supernatant with or without cell preservation solution to compare cell viability and biological characteristics at different time point. Wright Giemsa staining was used to compare cell morphology; cell counting, CCK-8 method, and trypan blue staining were used to compare the cell number, and flow cytometry was used to compare the cell viability. The expression of AML-ETO tumor fusion gene was detected by fluorescence quantitative RT-PCR. RESULTS: At different time points (8 h and 24 h), the survival, molecular biological characteristics and RT-PCR result of the cells in CSF with cell preservation solution were significantly better than those in normal cerebrospinal fluid. CONCLUSION Cell preservation solution can effectively improve the survival time and survival rate of leukemic cells, thereby increase the detection rate of CNS leukemia.
Central Nervous System Neoplasms ; Core Binding Factor Alpha 2 Subunit ; Humans ; Leukemia ; RUNX1 Translocation Partner 1 Protein

Objective: To investigate the antibacterial activity to Streptococcus mutans of a nisin-containing single-bond universal adhesive. Methods: Nisin was mixed into the bonding agent to produce concentrations ranging from 0.01 g/mL to 0.05 g/mL for the experiments, and adhesive without nisin was used as the control. Dentin-resin specimens were prepared for the microtensile strength test to evaluate changes in the bonding strength. The proper concentrations were selected for more tests. ① An agar diffusion test was applied with filter paper to detect the release of nisin, and adhesive without nisin was used as the negative control, 0.01 g/mL Nisin aqueous solution was used as the positive control. ② Solidification; resin adhesive specimens were prepared for the assessment of direct contact inhibition activity. ③ Confocal laser scanning microscopy was used to examine the effect of the adhesive on the biological film activity and the ability of Streptococcus mutans to produce extracellular polysaccharides. Results : Nisin did not significantly reduce the bond strength of the modified adhesive at 0.01-0.03 g/mL (P < 0.05); these concentrations were selected for the subsequent antibiosis experiment. Rings could not be observed in the agar diffusion test, except for in the group of adhesive modified with 0.01-0.03 g/mL nisin. Resin adhesive with 0.01-0.03 g/mL nisin could significantly inhibit the proliferation of Streptococcus mutans on the surface of the specimens. The confocal laser scanning microscopy results indicate that only the adhesive resin modified with nisin could reduce the bacteria in the biofilm and the production of extracellular polysaccharides. Conclusion Single-bond universal adhesive with 0.01-0.03 g/mL nisin can inhibit the growth of Streptococcus mutans and its biofilms on the bonding interface, as well as decrease the production of extracellular polysaccharides, and thus has the potential to decrease the occurrence of secondary caries.

Endodontic treatment with the use of dental operating microscope is a difficult part in teaching. We have applied cone beam computed tomography (CBCT) guided technology for microendodontic training of dental students who are in their 5th year of the 7 year course to pursue their master's degree. The process of teaching is constituted of preoperative analysis, operation guided by CBCT, postoperative therapeutic evaluation. And the result of teaching quality is acquired by questionnaire. This method improved student's capacities of analysis and solution in intractable cases and greatly motivated students' participa-tion, as well as promoting their learning efficiency. The application of this technique in teaching process compensates the deficiency of traditional teaching method by shaking off the fetters of experience-dependent pattern in the endodontic microscope teaching, and is worth to be popularized in endodontic education.

Objective: The aim of this study is to investigate the roles of Notch signaling and autophagy on mineral trioxide aggregate (MTA) induced differentiation of human dental pulp cells (hDPCs). Methods : Third molars from healthy human were collected and hDPCs were isolated by a combined digestion of collagenase Ⅰ and dispaseⅡ. Real time PCR were used to test the mRNA expression levels of alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and dentin sialophoprotein (DSPP) in MTA treated hDPCs in different time (24 h, 3 d and 7 d). The mineralization nodules formed by hDPCs with or without MTA treatment were detected by Von Kossa staining. Expressions of Notch1, Jagged1, Hes1, LC3Ⅱ/LC3 Ⅰand p62 in wild type and MTA treated hDPCs were detected by western blotting. Results: MTA extracted in a concentration of 0.1 mg/mL could promote the differentiation of hDPCs. Compared with that of wild type hDPCs, the expressions of Notch1, Hes1, or Jagged1 and p62 (P<0.01) in MTA treated hDPCs were significantly increased. MTA treatment showed inhibition effects on autophagy flux similar to Bafilomycin A1, a specific inhibitor of fusion between autophagosomes and lysosomes. Conclusion MTA could promote hDPCs differentiation with highly relevant in stimulating Notch1-Jagged1-Hes1 signaling and inhibition of autophagy flux.

OBJECTIVETo investigate the effect of epigallocatechin-3-gallate (EGCG) on biomodification of demineralized dentine substrate, in its permeability, hydrophobicity, and inhibition ability to collagen enzymatic degradation.

METHODSThe dentine substrates were treated with simulated pulpal pressure created by mixtures of 0.02%, 0.1% EGCG/bovine serum albumin (BSA) in acidic environment (pH4.4) for 48 h. A fluid-transport model was used to measure the fluid permeability through demineralized dentine substrate. Positive replicas of dentine substrate were fabricated before and after being subjected to acidic environment for scanning electron microscope (SEM) examination. The blank group contained no EGCG and the positive group were treated with Gluma desensitizer. Static contact angle measurements on demineralized dentin and 0.1% EGCG primed dentin were performed by contact angle analyzer. The priming time were 60 s, 120 s, 0.5 h, 1 h. Dentine specimens bonded with Adper single bond 2 were subjected to 100 mg/L collagenase and observed under SEM. Resin-bonded specimens (with 0.02%, 0.1%, 0.5% EGCG priming, or without EGCG priming) were created for micro-tensile bond strength evaluation (MTBS). Resin-bonded specimens after thermol cycling were created for MTBS evaluation.

RESULTSThe fluid permeability in the blank control group increased ([151.3±22.3]%), the fluid permeability in 0.1% EGCG/BSA group decreased ([23.7±6.3]%). Compared to the blank control group, the contact angle of 120 s, 0.5 h, 1 h groups increased by 31.0%, 53.5%, 57.8% in deep dentin and 37.4%, 59.3%, 62.4% in shallow dentin. The SEM examination showed that 0.1% and 0.5% EGCG priming for 120 s significantly increased dentin collagen's resistance to collagenase. The immediate MTBS of 0.1% and 0.5% EGCG groups were (29.4±4.8) and (19.8± 4.9) MPa. After thermol cycling, the MTBS of 0.1% and 0.5% EGCG groups were (19.9±5.1) and (15.3± 6.3) MPa.

CONCLUSIONSUnder acidic environment (pH4.4), the 0.1% EGCG can reduce dentine permeability under acidic environment. The 0.1% EGCG can increase hydrophobicity of dentin substrate, and strengthen dentin substrate's resistance to collagenase hydrolysis, thus increased the resin-dentin bonding durability.

Acid Etching, Dental ; Catechin ; analogs & derivatives ; pharmacology ; Collagen ; chemistry ; drug effects ; Collagenases ; pharmacology ; Composite Resins ; Dental Bonding ; Dental Cements ; Dental Pulp ; Dentin ; chemistry ; drug effects ; Dentin Permeability ; drug effects ; Dentin-Bonding Agents ; Glutaral ; pharmacology ; Hydrogen-Ion Concentration ; Hydrolysis ; Methacrylates ; pharmacology ; Microscopy, Electron, Scanning ; Pressure ; Resin Cements ; Serum Albumin, Bovine ; pharmacology ; Tensile Strength ; Time Factors

Objective To investigate the functions of sodium tripolyphosphate (STTP) and polyacrylic acid (PAA) in the process of collagen biomimetic mineralization.This would allow future applications to other collagen matrices such as bone collagen or 3-D collagen scaffolds.Methods Glass cover slips and transmission electron microscopy (TEM) grids were coated with reconstituted type Ⅰ collagen fibrils.Mineralization of the reconstituted collagens was demonstrated with scanning electron microscopy (SEM) and TEM using a Portland cement-containing resin composite and a phosphate-containing fluid in the presence of PAA and STTP.The rest were immersed in a biomimetic remineralization medium without PAA and/or STTP (control).Results In the presence of PAA and STTP in the mineralization medium,intrafibrillar mineralization based on the non-classical crystallisation pathway could be identified.Mineral phases were evident within the collagen fibrils as early as 12 h after the initially-formed amorphous calcium phosphate nanoprecursors were transformed into apatite nanocrystals.Collagens at 72 h were heavily mineralized with periodically arranged intrafibrillar apatite platelets.Conversely,only large mineral spheres with no preferred association with collagen fibrils were observed in the absence of biomimetic analogues in the medium (control).Conclusions Intrafibrillar apatite deposition can be achieved via biomimetic mineralization system containing PAA and STTP when amorphous calcium phosphate precursor is stabilized.