Objective：To establish a monoclone cell line of squamous cell carcinoma（SCC）in rat tongue mucosa and to study its biological characteristics. Methods：SCC in rat oral mucosa was induced by adding 4-nitroquinoline-1-oxide (4NQO) to the SD rat’s drinking water, and the cancer tissue was then cultured to obtain mixed cells in vitro. Mono cell cloning method was used for purification of the mixed tumor cells. The biological characteristics of the cells were studied by microscope observation, CCK-8 Cell Counting Kit, plate clone formation assay, flow cytometry assay and immunohistochemistry staining. Hypodermic inoculations of the cells in nude mice were performed to observe the tumor formation ability. Results：The tumor cells were spindle-shaped and expressed the proteins of cytokeratin, Vimentin and N-cadherin. The cellular population doubling time was 23.35 hours. The colony forming efficiency was 63.06% and the xenograft rate was 100％ in nu/nu BALB/C mice. Conclusions：Rca-T, an oral squamous cell carcinoma cell line derived from Sprague-Dawley rat tongue mucosa carcinoma, was established successfully. This cell line would be a model for basic and clinical research of oral cancer.

Objective：To investigate the role of the histone demethylases JMJD3 in regulating the pluripotency and the osteogenic differentiation of the bone marrow stromal cells（BMSCs）in vitro. Methods：Gradient centrifugation and adherent culture were used to isolate the BMSCs from rat tibia, and the lenti-virus of the JMJD3-shRNA and GFP (as the control) were constructed. The expression of H3K27me3 and the pluripotent transcription factors (Oct4/Nanog/Sox2) were detected by Western blot. The colony-forming efficiency was compared between JMJD3-shRNA group and GFP group. The different osteogenic ability of the JMJD3-shRNA group and the control group were analyzed by real-time RT-PCR, Western blot and Alizarin red staining after osteogenic induction. Results：Compared with the control, the expression of H3K27me3 was higher in JMJD3-shRNA group. The JMJD3 shRNA group possessed stronger colony-forming ability, expressed higher stemness markers (Oct4/Nanog/Sox2), compared with the control group. After 7-day osteogenic induction in vitro, the BMSCs’ osteogenic ability declined in JMJD3-shRNA group. After 14-day osteogenic induction, the calcium nodules of JMJD3-shRNA group were less than that of the control group. Conclusions：Inhibition of JMJD3 can enhance BMSCs’ stemness, and suppress their osteogenic differentiation.

Objective：To investigate the expression of osteopontin (OPN) and CD44v6 and their significance in keratocystic odontogenic tumor (KCOT) before and after decompression. Methods：All 16 pairs of paraffin- embedded tissue specimens of KCOT before and after decompression were collected and then used for immunohistochemical detection of OPN and CD44v6. The results were statistically analyzed. Results：The expression of OPN in KCOT was down-regulated after decompression（P＜0.05）.And CD44v6 expression in postoperative KCOT epithelium was significantly less than that in preoperative KCOT epithelium（P＜0.05）. Conclusions：The local aggressive behavior of KCOT epithelium after decompression was decreased, which may be part of the mechanisms of decompression therapy.

Objective：To observe the effects of Penicillin-Streptomycin on the proliferation, odonto-and osteogenic differentiation and the expression of the inflammatory cytokines of inflamed human dental pulp stem cells (iDPSCs) in vitro. Methods：iDPSCs were isolated from inflamed human dental pulp and cultured respectively in alpha minimum essential medium(α-MEM) or containing 100U/ml Penicillin-Streptomycin. The proliferation ability of iDPSCs was evaluated by MTT colorimetric assay. Alkaline phosphotase (ALP) activity, real-time RT-PCR and Western blot were used to examine the odonto/osteogenic potential-the the expression of RUNX2/RUNX2,DSP/DSPP,OCN/OCN and the expression of TNF-α of iDPSCs. Results：MTT assay showed that 100U/ml Penicillin-Streptomycin had no effect on the proliferation of iDPSCs, ALP activity assay, real-time RT-PCR and Western blot showed that there was no difference between Penicillin-Streptomycin group and α-MEM group (P>0.05). The expression of TNF-α decreased in Penicillin-Streptomycin group (P<0.01). Conclusions：Penicillin-Streptomycin significantly suppressed the expression of inflammatory cytokines in inflammatory dental pulp stem cells, and has no noticeable effect on the proliferation and differentiation of the cells.

Objective : To assesse the applicability of Haavikko method in estimating the dental age of Nanjing children. Methods : A total of 629 dental panoramic radiographs(392 boys and 237 girls) of children in Nanjing were collected for the study on the basis of predetermined inclusion and exclusion criteria .All permanent mandibular teeth on the left side of the radiograph(except for the third molars) were assessed ,and the stages of development of these teeth were recorded according to Haavikko method .Paired t-test was performed between the chronological age and dental age which was scored by Haavikko method .A single-factor model was used to show the relationship between chronological age and dental age of Nanjing children. Result: A statistically significant difference was found between chronological age and dental age (P<0.01). Dental age scored by Haavikko method showed an underestimate of 0.6 years and 1.0 years in males and females. We set up the mathematical model between dental age and chronological age, then got the curve-fitting equation. Conclusions: The curve-fitting equation can be used to assess chronological age of Nanjing children, cause it shows No statistically significant difference between natural and dental age by using the equation.

Objective： To investigate the relationship between fluoride iontophoresis and remineralization of human root caries in vitro. Methods：Thirty-five human root samples were demineralized by acid-etching, randomly divided into five groups, then pretreated with 1.23%fluoride foam, 4%NaF solution with iontophoresis, 4%NaF solution simply and physiological saline with iontophoresis respectively. Then the samples were remineralized by pH-cycling, and the effects of remineralization were analyzed by laser scanning confocal microscope (LSCM) while lesions were photoed by scanning electronic microscope (SEM). Results：Observed by SEM, the two groups pretreated with 1.23%fluoride foam and 4%NaF solution with iontophoresis had smoother surfaces and they had significant differences in reducing demineralized depth and area compared with other groups (P <0.01)analyzed by LSCM, but there was no significant difference between themselves(P >0.05). Conclusions：Both fluoride iontophoresis and fluoride foam can promote remineralization of root caries, but have no significant differences in reducing demineralized depth and area.

Objective：The aim of the study is to evaluate the erosive effect on young permanent teeth enamel by carbonated beverage, fruit juice, tea drinks and lactate drinks. Methods：130 young permanent teeth were randomly divided into 13 groups, and were soaked in 12 beverages and deionized water respectively. A laser fluorescence system was used to keep a quantitative record. Results：By observing the dental erosion effected by the beverages before and after the experiment, a significant difference of demineralization was found in carbonated beverage and fruit juice (P＜0.05). But herbal tea and two kinds of lactate drinks did not show any significant erosive effect (P＞0.05). Conclusions：Most of the beverages can cause dental erosion of young permanent teeth. It is suggested that beverages consumption by children should be controlled.

With the boost of orthodontics,some side effects during orthodontic treatment have raised clinician’s attention .But due to the variety of the shape、height and thickness of the alveolar bone and ability of remodeling, the accurate prejudice of changes of alveolar bone after orthodontic treatment is still a challenge.A high quality CBCT technique is well suited for research on alveolar bone changes during orthodontic treatment as it provides access to anatomic structures that cannot be evaluated in conventional radiographs, high measurement accuracy and precision.This review tracks the mechanics of alveolar bone remodeling and the changes of alveolar bone during orthodontic assessed by CBCT

Dental caries is one of the third major non-communicable diseases following the cardio-cerebrovascular disease and tumor.It would affect the function of masticatory，beauty and pronunciation ,even to cause deuteropathy.Early enamel caries is the initialization phase of dental caries,and it is also the critical period to treatment.The prevention and treatment have fluorination method and pit and fissure sealant,however, these strategy has considerable limitations,which limit the clinical application.Infiltration of non-cavitated caries lesions with light-curing resins could lead to an arrest of lesion progression because of its superior physical and chemical performance, gradually attracted widespread attention in recent years.The aim of this study is to discuss the permeability,aging resistant performance and surface micro-hardness of the resin infiltration.

This paper discusses the research progress of soft tissue expansion from the traditional to osmotically active hydrogels of soft tissue expander, comprehensively discusses the status of several kinds of super-absorbent polymer used for oral soft tissue swelling in soft tissue swelling.