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.

OBJECTIVETo analyze the expression of foreign gene in the filial generation of the transgenic plants on the base of the original transgenic tomatoes seeds carrying the gene encoding saliva-binding region (SBR) in PAc of Streptococcus mutans (S. mutans) gained.

METHODSThe tomatoes total DNA was extracted by CTAB methods, and the filial generation transgenic tomatoes carrying the gene encoding SBR in PAc of S. mutans were selected by PCR. The tomatoes total RNA was extracted by trizol and the transcription of the foreign gene was analyzed by RT-PCR. Protein was extracted from fruit tissue and the content of the total protein was determined by Bradford's methods G250. The expression of foreign protein was analyzed by Western blot and the lever of the foreign protein was analyzed by ELISA.

RESULTSThe fragment encoding SBR in S. mutans PAc gene integrated in the tomato genomic DNA and was expressed. The foreign protein lever was up to 1.2% of the total soluble protein in tomato fruit tissue.

CONCLUSIONThe foreign protein gene in the filial generation of the transgenic plants could express the foreign protein.

Lycopersicon esculentum ; Saliva ; Streptococcus mutans

OBJECTIVEThe purpose of this study is to construct plant expression plasmid containing the gene encoding chimera SBR-CT delta A1.

METHODSThe target gene fragment P2, including the gene-encoded chimera SBR-CT delta A1 (3,498-5,378 bp), was obtained by standard PCR amplification. The PCR products were ligated with pGEM-easy vector through TA clone to form plasmid pTSC. The plasmid pTSC and plasmid pPOKII were digested by restricted endonuclease BamHI and KpnI, and the digested products were extracted and purified for recombination. Then the purified P2 and plasmid pPOKII were recombined by T4 DNA ligase to form recombinant plasmid pROSC; inserting bar gene into the plasmid and form pROSB plasmid. The recombined plasmids were isolated and identified by restricted endonuclease cutting and Sanger dideoxy DNA sequencing.

RESULTSP2 gene was linked to pPOKII plasmid and formed recombinant plasmid pROSC. The DNA sequence and orientation were corrected. And bar gene was inserted into pPOSC and form recombinant plasmid pROSB.

CONCLUSIONPlant expression vector pROSC and pROSB containing the gene encoding chimera SBR-CT delta A1, which may provide useful experiment foundation for further study on edible vaccine against caries have been successfully constructed.

Adhesins, Bacterial ; genetics ; Animals ; Chimera ; genetics ; Cloning, Molecular ; Dental Caries ; prevention & control ; Gene Transfer Techniques ; Genetic Vectors ; Lipoproteins ; genetics ; Lycopersicon esculentum ; genetics ; metabolism ; Plasmids ; genetics ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; Recombination, Genetic ; Streptococcal Vaccines ; genetics ; immunology ; Streptococcus mutans ; genetics ; immunology ; Vaccines, DNA ; genetics

OBJECTIVETo investigate genetic etiology of fetal urinary abnormalities with array-based comparative genomic hycridization(array-CGH).

METHODSThirty-two fetuses with variable urinary abnormalities but normal karyotyping by conventional cytogenetic technique were selected. DNA from the fetuses and their parents samples were prepared and hybridization with Affymetrix cytogenetic 2.7M arrays by follwing the manufacture's standard protocol. The data were analyzed by special CHAS software packages.

RESULTSBy using array-CGH detection, genomic imbalanced copy number variations (CNVs) were identified in night fetuses(28%), four out of night CNVs were inherited from parental samples; two were indicated to be benign variants(6%) in the database; and the other three CNVs (9%) were all de novo adjacent microdeletions and microduplication mapping on to common chromosome 1q21.1 region, within which was genitourinaty system function associated gene PDZK1.

CONCLUSIONThe incidence of genomic unbalanced variations in fetuses with congenital urinary malformations is approximately 28%, including about 9% pathogenic variations. Copy number variations (CNVs) of chromosome 1q21.1 region are associated with congenital urinary malformations which may be due to haploinsufficiency or overexpression of PDZK1 gene.

Chromosome Deletion ; Chromosomes, Human, Pair 1 ; Comparative Genomic Hybridization ; DNA Copy Number Variations ; Female ; Humans ; Kidney ; abnormalities ; Pregnancy ; Prenatal Diagnosis

The application of adhesive root canal filling materials is the tendency in root canal obturation. The orientation is to develop the adhesive core material and sealer making a whole structure. In this review, we summarized the researches on the resin-dentin adhesion in the root canal obturation.
Dentin ; Dentin-Bonding Agents ; Humans ; Root Canal Filling Materials ; Root Canal Obturation

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

OBJECTIVETo investigate the tumor-associated antigen CA125 expression in the serum and cervical and vaginal secretions in women during normal reproductive period, and explore the clinical value of detecting tumor markers in the cervical and vaginal secretions.

METHODSA total of 145 women in reproductive period were divided into 3 age groups (20-29 years, 30-39 years, and over 40 years), and their CA125 levels in cervical secretion, vaginal secretion and serum were detected by automatic electro-chemiluminescent immunoassay.

RESULTSCA125 levels in the cervical secretion, vaginal secretion and serum showed no significant difference between the 3 age groups (P>0.05). In each group, CA125 levels differed significantly between the cervical secretion, vaginal secretion and serum (P<0.001). In the 145 women, the average CA125 level was 497.82 - or + 75.29 U/ml in the cervical secretion, 114.66 - or + 26.40 U/ml in vaginal secretion and 18.06 - or + 3.35 U/ml in serum, showing significant differences between them (P<0.001).

CONCLUSIONCA125 expression level is significantly higher in the cervical and vaginal secretions than in the serum in women in normal reproductive period, and its levels in cervical and vaginal secretions can be more sensitive and convenient for early detection of related diseases.

Adult ; Biomarkers ; analysis ; CA-125 Antigen ; blood ; metabolism ; Cervix Mucus ; metabolism ; Female ; Humans ; Middle Aged ; Vagina ; secretion ; Young Adult

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 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.

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.