[Occluding effects of desensitizer containing NovaMin combined with fluor protector on dentinal tubules:an in vitro study].

Puppose: To observe the occlusion effect, acid resistance and abrasion resistance of desensitizer containing NovaMin combined with fluor protector on dentin tubules, in order to provide theoretical basis for clinical treatment of dentin hypersensitivity.

Methods: Thirty extracted intact and non-carious human premolars for orthodontic treatment were selected and made into 2 mm thick dentin slices. Each slice was cut into 4 parts to form 120 sensitive dentin models and randomly divided into 4 groups (n=30).

Impacts of fluorescent superparamagnetic iron oxide (SPIO)-labeled materials on biological characteristics and osteogenesis of bone marrow mesenchymal stem cells (BMSCs).

The aim of this study was to investigate the impacts of fluorescent superparamagnetic iron oxide particles (Molday ION Rhodamine B, MIRB) on bioactivities and osteogenetic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). The Cell Counting Kit-8 (CCK-8) method was used to detect the proliferation of superparamagnetic iron oxide (SPIO)-labeled BMSCs and observed the distribution of MIRB in cells; real time -polymerase chain reaction (RT-PCR) method was used to analyze the expressions of such osteogenesis-related genes as bone sialoprotein, alkaline phosphatase (ALP), RUNX2, bonemorphogeneticprotein-2 (BMP-2), type 1 collagen (COL-1) and type 3 collagen (COL-3); ALP-Alizarin red staining and poly-biochemical analyzer were used to qualitatively and quantitatively analyze the osteogenetic metabolites. The labeled MIRB particles distributed in the cytoplasm of BMSCs, the diameter of larger particles could be up to several hundred nanometers, and concentrated around the nuclei, the particles far away from the nuclei were smaller, but the labeled-cells' skeletons and adherent morphology did not change significantly; under the concentration of 25 μg Fe/mL of, MIRB did not affect cellular viabilities of BMSCs, but the gene expressions of bone sialoprotein, ALP, RUNX2 and BMP-2 were decreased, and the secretion amount of ALP and osteocalcin were also declined.

Different study conditions between dental students in China and Japan.

Background: The purpose of this study was to compare the study conditions of dental students towards dental education in China and Japan.

Methods: 60 students from the Stomatology School of China Medical University and 51 students from the Dental Faculty of Kyushu University, Japan, participated in this study. Information was derived from a self-answered questionnaire consisting of 10 items.

[The effect of fluoride on the expression of GRP-78 and caspase-12 in rat ameloblast].

Purpose: To study the effect of GRP-78 and caspase-12 on fluoride-induced endoplasmic reticulum stress and apoptosis in rat ameloblast, and explore whether fluoride-induced endoplasmic reticulum stress results in the occurrence of apoptosis.

Methods: The cell activity of ameloblast cultured in various concentrations of fluoride was measured by CCK8 and flow cytometry; Real-time RT-PCR and Western blot were used to analyze the endoplasmic reticulum chaperone GRP-78 and caspase-12 genes and the expression of related proteins. The data was analyzed with SPSS13.

[The effect of various irrigants on apically extruded debris: an in vitro study].

Purpose: To compare the amount of debris extruded apically from root canals when different irrigants were used.

Methods: Fifty-eight extracted single-rooted human mandibular premolars with straight root canals were used. The teeth were randomly divided into control group (group A, n=7) and 3 experimental groups (group B,C,D,n=17).

[Application of role-play simulation in pre-clinical practice of the fourth grade students in department of endodontics].

Purpose: To apply role- play simulation in pre-clinical practice of the fourth grade students in department of endodontics.

Methods: Thirty-two students were randomly divided into 2 groups, there were 16 students in each group. Students in one group were taught with role-play simulation while the other group with lecture-based learning method.

[Study of relationship between different contents of zinc and antibacterial activity on calcium phosphate coating modified by plasma electrolytic oxidation method].

Purpose: Calcium phosphate activity coating containing different contents of zinc was deposited onto the surface of pure titanium modified by plasma electrolytic oxidation. The physical and chemical properties of different contents of zinc were compared among three groups, and the influence on antibacterial activity of P.gingivalis (Pg) and A.

[Effect of fluoride on the viability and apoptosis of ameloblasts in vitro].

Purpose: To evaluate the effect of fluoride on viability of rat ameloblasts in vitro.

Methods: The ameloblasts of rat was exposed to different concentrations of NaF (0, 0.4, 0.

[Preliminary study on root canal morphology of maxillary second molars].

Purpose: To investigate the root canal morphology and anatomy of maxillary second molars using transparent tooth technique and cone-beam computed tomography (CBCT), and explore the consistency of 2 methods in identifying root canal configurations and morphology.

Methods: Fifty extracted maxillary second molars were scanned by CBCT and analyzed using assistant software. Root canal configurations of each root were identified based on Vertucci's classification and recorded.

[Effect of pituitary tumour transforming gene on invasion and metastasis of salivary adenoid cystic carcinoma].

Purpose: To study the effect of pituitary tumour transforming gene (PTTG) on invasion and metastasis of salivary adenoid cystic carcinoma.

Methods: The expression of PTTG and bFGF was investigated in 40 salivary adenoid cystic carcinoma tissues and 20 normal salivary tissues by immunohistochemistry. Pearson's Chi-square test and Spearman correlation analysis were used to analyze the data using SPSS 11.

[Effect of fluoride on the expression of endoplasmic reticulum chaperone in ameloblast of rat incisor].

Purpose: To investigate the effect of different concentrations of fluoride on the expression of endoplasmic reticulum chaperone, and to explore the mechanism of dental fluorosis in rat.

Methods: Thirty Wistar rats were randomly divided into 3 groups. Immunohistochemistry was used to detect the expression of CRT, GRP78, XBP-1 and caspase-12 in rat incisors.

[Application of problem-based learning in pre-job training of postgraduate students in department of endodontics].

Purpose: To apply problem-based learning (PBL) in pre-job training of postgraduate students in department of endodontics.

Methods: Thirty master degree postgraduate students of China Medical University were randomly divided into 2 groups, there were 15 students in each group. One group were taught with PBL method while the other group with lecture-based learning (LBL) method.

[Computer aided design and computer aided manufacture of template for crown lengthening].

Purpose: To introduce a method applied in computer aided design and computer aided manufacture (CAD-CAM) of template for crown lengthening.

Methods: Point cloud data of dental stone model of the patient in the plan of crown lengthening surgery was obtained by laser scanning. The following processes were carried out, constructing 3-D curve of the gingiva, drawing template outline on the triangle mesh model, shelling it for 3-D model of template, and transferring the data to rapid prototyping equipment for manufacture.

[Effect of NF-κB on the expression of interleukin-6 induced by lipopolysaccharides of Porphyromonas endodontalis in MC3T3-E1 cells].

Purpose: To investigate the effect of NF-κB signaling on the expression of interleukin-6(IL-6) induced by lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) in MC3T3-El cells.

Methods: MC3T3-E1 cells were pretreated with BAY-117082 for 1 h, and then were treated with 10 mg/L P.

[Effect of lipopolysaccharides extracted from Porphyromonas endodontalis on the expression of p38 and ERK1/2 in osteoblast].

Purpose: To investigate the effect of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of p38 and ERK1/2 in osteoblast.

Methods: MC3T3-E1 cells were stimulated with 10 μg/mL P.

[The effect of different concentrations of fluoride on the expression of Smad2/3 in ameloblast of rat incisor].

Purpose: To investigate the effect of different concentrations of fluoride on the expression of Smad2/3 which is a specific intracellular signal transduction molecule of TGF-β, and to explore the mechanism of dental fluorosis in rat.

Methods: Forty Wistar rats were randomly divided into 3 groups.HE and immunohistochemistry were used to detect the changes of the ameloblasts and the expression of Smad2/3 in rat incisors.

[Comparative study on the shaping ability of canals with 2 new nickel- titanium rotary instruments].

Purpose: To compare the shaping ability of two nickel-titanium rotary systems: Mtwo and K3.

Methods: Thirty-six mesio-buccal root canals of maxillary first molars were divided into two groups: group A(> or =20> or =) and group B(<20 degrees ),according to the angle of the canal. Then, each group was randomly divided into two subsets and prepared by Mtwo,K3, respectively.

[Results of 30 children treated under dental general anesthesia in pediatric dentistry].

Purpose: To determine the age and sex characteristics of the children and type of dental procedures performed under dental general anesthesia (DGA) and to assess the results after six months to one year's follow-up.

Methods: A sample of 30 patients treated under dental general anesthesia (DGA) during 2006-2007 in the Department of Pediatric Dentistry of China Medical University was reviewed. All the teeth were treated one time.

[Study of nHACP/CF co-cultured with osteoblasts in vitro].

Purpose: To investigate the effect of nHACP/CF on coherence and proliferation of osteoblast.

Methods: The rat osteoblasts were isolated and cultured, then co-cultured with nHACP/CF in vitro. The cells were observed under cytochemical staining for ALP; the cell-material complex was observed under electronic scanning microscope, MTT was used for detection of cell proliferation,and ALP activity was determined at different times.

[Expression of telomerase genes hTRTmRNA in oral squamous cell carcinomas].

Purpose: To investigate the expression of telomerase genes in oral squamous cell carcinomas(OSCC).

Methods: Telomerase genes hTRTmRNA in 65 cases of OSCC, 25 cases of epidermal cells with abnormal hyperplasia and 20 cases of normal oral mucosa were detected by in situ hybridization. The digoxin-labelled probe was targeted to reverse transcription domain.

[Expression of Interleukin-8 in KB cells infected with Candida albicans].

Purpose: To investigate the change of interleukin-8 (IL-8) in oral epithelial cells (KB cells) infected with Candida albicans.

Methods: Two-site ELISA and RT-PCR were applied to determine the levels of IL-8 protein or mRNA expression in the KB cells induced by hyphae, yeast, killed Candida albicans and medium respectively. The unpaired Student's t test was used to analyse the data.