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Table of Content
01 December 2015, Volume 33 Issue 6
  • Oral microbiota: a promising predictor of human oral and systemic diseases
    Xu Xin, He Jinzhi, Zhou Xuedong
    West China Journal of Stomatology. 2015, 33(6):  555-560.  doi:10.7518/hxkq.2015.06.001
    Abstract ( 1009 )   HTML ( 63 )   PDF(pc) (807KB) ( 1363 )   Save
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    A human oral microbiota is the ecological community of commensal, symbiotic, and pathogenic microorganisms found in human oral cavity. Oral microbiota exists mostly in the form of a biofilm and maintains a dynamic ecological equilibrium with the host body. However, the disturbance of this ecological balance inevitably causes oral infectious diseases, such as dental caries, apical periodontitis, periodontal diseases, pericoronitis, and craniofacial bone osteomyelitis. Oral microbiota is also correlated with many systemic diseases, including cancer, diabetes mellitus, rheumatoid arthritis, cardiovascular diseases, and preterm birth. Hence, oral microbiota has been considered as a potential biomarker of human diseases. The “Human Microbiome Project” and other metagenomic projects worldwide have advanced our knowledge of the human oral microbiota. The integration of these metadata has been the frontier of oral microbiology to improve clinical translation. By reviewing recent progress on studies involving oral microbiota-related oral and systemic diseases, we aimed to propose the essential role of oral microbiota in the prediction of the onset, progression, and prognosis of oral and systemic diseases. An oral microbiotabased prediction model helps develop a new paradigm of personalized medicine and benefits the human health in the postmetagenomics era.
    The dispute and prospect of sedation and analgesia treatments in outpatient dental procedures
    Yu Cong
    West China Journal of Stomatology. 2015, 33(6):  561-564.  doi:10.7518/hxkq.2015.06.002
    Abstract ( 833 )   HTML ( 23 )   PDF(pc) (762KB) ( 805 )   Save
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    The topic of eliminating the fear or pain of patients during dental therapy is gaining increasing attention from dentists across the country. The field of painless dental therapeutics involves a wide range of subjects, including stomatology, anesthesiology, and hospital management. We summarized the characteristics of sedation and analgesia technology in outpatient oral therapy, reviewed the common sedative and analgesic treatments, and discussed the disputes on the use of sedation and analgesia in dental procedures. We also reviewed the trends and breakthroughs in this area on the basis of our own clinical experiences.
    Dental plaque microcosm biofilm behavior on a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt
    Wu Junling, Zhang Qiang, Sun Ruinan, Zhu Ting, Ge Jianhua, Zhou Chuanjian
    West China Journal of Stomatology. 2015, 33(6):  565-569.  doi:10.7518/hxkq.2015.06.003
    Abstract ( 999 )   HTML ( 7 )   PDF(pc) (1050KB) ( 785 )   Save
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    Objective To develop a resin composite incorporated with nano-antibacterial inorganic filler containing longchain alkyl quaternary ammonium salt, and to measure its effect on human dental plaque microcosm biofilm. Methods A novel nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt was synthesized according to methods introduced in previous research. Samples of the novel nano-antibacterial inorganic fillers were modified by a coupling agent and then added into resin composite at 0%, 5%, 10%, 15% or 20% mass fractions; 0% composite was used as control. A flexural test was used to measure resin composite mechanical properties. Results showed that a dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming unit (CFU) counts, lactic acid production, and live/dead assay of biofilm on the resin composite were calculated to test the effect of the resin composite on human dental plaque microcosm biofilm. Results The incorporation of nano-antibacterial inorganic fillers with as much as 15% concentration into the resin composite showed no adverse effect on the mechanical properties of the resin composite (P>0.05). Resin composite containing 5% or more nano-antibacterial inorganic fillers significantly inhibited the metabolic activity of dental plaque microcosm biofilm, suggesting its strong antibacterial potency (P<0.05). Conclusion This novel resin composite exhibited a strong antibacterial property upon the addition of up to 5% nano-antibacterial inorganic fillers, thereby leading to effective caries inhibition in dental application.
    Establishment of a miniature pig model of mandibular osteoradionecrosis
    Li Song, Fang Dianji, Wang Zhanyi, Zhai Lulu, Ning Zhaorong, Guo Yanwei
    West China Journal of Stomatology. 2015, 33(6):  570-574.  doi:10.7518/hxkq.2015.06.004
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    Objective To establish a miniature pig model of mandibular osteoradionecrosis (ORN). Methods A single dose of irradiation (IR25 Gy, 28 Gy) was delivered via an electronic linear accelerator to the right mandible of 24 miniature pigs by utilizing three dimensional conformal radiotherapy (3D-CRT). The first molar of the mandible was extracted 2 months after radiation. Mandibular ORN was diagnosed through gross observation, X-ray film, CT, and histopathologic examination. Results At 3–4 months after radiation, all animals suffered from mandibular ORN after dental extraction. The symptoms of ORN were more severe in the 28 Gy group than in the 25 Gy group. Conclusion A miniature pig model of mandibular ORN can be established through 25 Gy irradiation+dental extraction.
    Myeloid-derived suppressor cell expression and significance in peripheral blood and tongue lesions of mouse
    Chu Mei, Liao Guiqing, Tang Wen, Zhou Yuan, Su Yuxiong, Liang Yujie
    West China Journal of Stomatology. 2015, 33(6):  575-580.  doi:10.7518/hxkq.2015.06.005
    Abstract ( 535 )   HTML ( 6 )   PDF(pc) (1706KB) ( 547 )   Save
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    Objective To explore the myeloid-derived suppressor cell (MDSC) expression in the peripheral blood and lesions of 4NQO-induced tongue carcinoma in mouse. Methods The established 4NQO mouse model was used to analyze the distribution of MDSC and T cell subsets in the peripheral blood by flow cytometry. The relations of MDSC with T cell subsets and CD4+/CD8+ changes were evaluated. The distribution of MDSC in the lesions of tongues was analyzed by immunohistochemistry, and the expression of arginase 1 (ARG-1) in tongue tissues was detected by real-time polymerase chain reaction. Results During tumor progression, a significant increase was observed in the frequency of MDSC in the peripheral blood of 4NQO treated mice (P<0.01). The frequency of MDSC was positively correlated with systemic CD3+CD8+T cells but negatively correlated with the CD4+/CD8+ ratio. Squamous cell carcinomas were extensively infiltrated with MDSC, whereas dysplastic area and normal tongue mucosa had only sparse MDSC infiltration. The majority of MDSCs were located in the stroma, particularly along the tumor invasive front. Moreover, 4NQO-treated mice showed significantly higher ARG-1 mRNA levels in the tumor site (P<0.01). Conclusion MDSC may contribute to oral tumor progression and represents a potential target for immunotherapy of oral cancer.
    Preliminary study on E-cadherin expression in dexamethasone-induced palatal cleft in mouse
    Pang Xiaoxiao, Li Li, Ma Li, Zheng Qian, Li Chenghao
    West China Journal of Stomatology. 2015, 33(6):  581-584.  doi:10.7518/hxkq.2015.06.006
    Abstract ( 663 )   HTML ( 4 )   PDF(pc) (1414KB) ( 511 )   Save
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    Objective The glucocorticoid dexamethasone (DEX) can induce palatal cleft; however, the mechanism involved remains unclear. E-cadherin is an important cell adhesion molecule, and it can significantly affect cell fate and embryonic development. Recent studies have indicated that E-cadherin expression in palatal epithelial cells is suppressed in normal palate fusion. This study aimed to determine whether the change in E-cadherin expression is related to the incidence of cleft palate in DEX-induced mice. Methods Mice were divided into the experimental group and the control group. Pregnant mice were injected with DEX on E10.0–E12.0, whereas mice in the control group were injected with normal saline. Hematoxylin and eosin (HE) staining, immunohistochemistry, and real-time quantitative polymerase chain reaction were employed to evaluate the effect of DEX on fetal mouse palatal processes, particularly the changes in E-cadherin and β-catenin expression levels in the phases of the experimental and control groups. Results Data indicated that the incidence of cleft palate in the DEX group was 43.59% (17/39), whereas that in the control group was only 3.03% (1/33). The results of HE staining showed that the obviously shortened palatal processes could not contact and fuse with one another in the DEX-treated mice model compared with those in the control group. The ectopic expression of E-cadherin in embryonic palatal mesenchymal cells was also analyzed. The expression levels of E-cadherin and β-catenin in the experimental group were higher than those in the control group. Conclusion These findings indicated that DEX could induce E-cadherin gene upregulation and ectopic expression, as well as high β-catenin expression, thereby inhibiting the growth of mesenchyme cells and cleft palate.
    Clinical symptoms and temporomandibular joint disc deformity study of Wilkes Ⅲ stage patients treated with arthrocentesis
    Zhang Nan, Jiao Guoliang, Wu Zhongyin
    West China Journal of Stomatology. 2015, 33(6):  585-588.  doi:10.7518/hxkq.2015.06.007
    Abstract ( 580 )   HTML ( 6 )   PDF(pc) (1282KB) ( 484 )   Save
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    Objective This study aims to evaluate the effectiveness of arthrocentesis on Wilkes Ⅲ stage patients. Clinical examinations and magnetic resonance imaging (MRI) findings before treatment and six months after treatment were compared and analyzed. Methods A total of 137 outpatients diagnosed with temporomandibular joint internal derangement (TMJID) associated with Wilkes Ⅲ stage through clinical examination and MRI findings from January 2013 to December 2013 were randomly included. All the patients were successfully treated with arthrocentesis. Moreover, all the patients accepted clinical and MRI examination before arthrocentesis treatment and six months after. Clinical examination included visual analogue scale and opening degree, whereas MRI examination included articular disc morphology and effusion in the upper compartments. Statistical analysis was performed using SPSS 20.0. Results Results showed that the average score of visual analogue scale six months after treatment was significantly lower than that before treatment (P<0.05). The success rate was 78.1% (107/137). The rate of disc deformity after arthrocentesis treatment was higher than that before the treatment. By contrast, the positive rate of effusion after arthrocentesis was significantly lower than that before the treatment (P<0.05). Bilaminar zone adaptive changes (disk-like) were found in seven cases (5.1%, 7/137) after treatment. Conclusion Arthrocentesis could effectively relieve pain of the TMJID patients. Furthermore, MRI results indicated that arthrocentesis could significantly decrease articular effusion. Arthrocentesis was effective for the treatment of Wilkes Ⅲ stage in the short term. Adaptive changes in bilaminar zone occurred in a few patients. However, serious disc deformity with the passage of time is a trend that has been observed.
    Effects of hypnotic and musical relaxation therapy on the treatment of the parents of children with cleft lip and/or palate
    Zhang Yanyan, Gong Caixia, Zhang Xiaolin, Chen Ying, Xu Jingchen, Ha Pin, Li Jingtao, Shi Bing
    West China Journal of Stomatology. 2015, 33(6):  589-592.  doi:10.7518/hxkq.2015.06.008
    Abstract ( 877 )   HTML ( 16 )   PDF(pc) (760KB) ( 560 )   Save
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    Objective To evaluate the effectiveness of hypnotic and musical relaxation therapy and psychological consultation for parents of children with cleft lip and/or palate (CLP) and to provide a scientific basis of clinical-psychological treatment options. Methods Sixty-six subjects with children with CLP participated in this study. The subjects were randomly assigned to a test group (n=33) and a control group (n=33). The test group was treated with hypnotic and musical relaxation therapy; the control group were subjected to psychological consultation. Anxiety and depression states were evaluated by using a self-rating anxiety scale (SAS) and a self-rating depression scale (SDS) before and after treatment was administered. Results 1) The test group demonstrated a significant decrease in SAS and SDS scores (t=2.855, P<0.01; t=2.777, P<0.01). The control group showed a significant decrease in the SAS score (t=1.831, P<0.05) but failed to show a significant change in the depression score (t=0.909, P>0.05). 2) The test group yielded a higher percentage of remission indicated by the SDS scores than the control group (test group=75.76%; control group=60.61%; P<0.05). The test group also displayed a higher percentage of remission indicated by the SAS scores than the control group (test group=78.79%, test group=69.70%; P<0.05). Conclusion Hypnotic and musical relaxation therapy can more effectively reduce the scores of the anxiety and depression states of the parents of patients with cleft lip and/or palate than psychological consultation.
    Factors influencing oral insurance among children in Chengdu
    Chen Wen, Zhang Yanyan, Jiang Jinghui, Zhang Jingxian, Shan Xuepeng, Qu Xing, Hua Chengge,
    West China Journal of Stomatology. 2015, 33(6):  593-596.  doi:10.7518/hxkq.2015.06.009
    Abstract ( 649 )   HTML ( 8 )   PDF(pc) (784KB) ( 653 )   Save
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    Objective This study aimed to investigate the value of child oral health for Chengdu parents, their intentions, and factors influencing their decision to acquire oral insurance coverage for their childrens. Methods A total of 562 Chengdu parents were interviewed using questionnaires by convenient sampling, and the results were analyzed using SPSS 20.0. Results The age of children (B=-1.741, P=0.004), age of parents (B=2.031, P=0.003), level of oral discomfort (B=0.569, P=0.000), incurring/not incurring oral care expenses in the previous year (B=1.897, P=0.014), the last time parents had teeth cleaned (B=0.777, P=0.006), and acquiring/not acquiring commercial insurance coverage (B=1.632, P=0.031) significantly influenced the intention of acquiring child oral insurance. Conclusion Child oral health, health and insurance awareness of parents, and other factors influenced the intention of parents to purchase oral insurance coverage for their children, which were significant to establish pediatric dental insurance.
    Investigation of teeth number and morphology abnormalities in children at the mixed dentition stage
    Ling Yuqi, Zhang Qiong, Zou Jing
    West China Journal of Stomatology. 2015, 33(6):  597-601.  doi:10.7518/hxkq.2015.06.010
    Abstract ( 1177 )   HTML ( 14 )   PDF(pc) (1452KB) ( 883 )   Save
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    Objective This study aims to investigate the prevalence and distribution of teeth number and morphology abnormalities in Chinese pediatric patients’ permanent teeth at the mixed dentition stage by performing panoramic radiographs analysis. Methods A total of 4 347 panoramic radiographs of pediatric patients aged 5 years to 15 years who were admitted to the hospitals from September 2011 to September 2013 were reviewed. The presence of teeth number and morphology abnormalities were recorded as follows: congenitally absent teeth, supernumerary teeth, odontoma, microdontia, fused teeth, dilaceations, and cusp deformity. SPSS 16.0 software was used for statistical analysis. Results The prevalence of teeth number and morphology abnormalities in pediatric patients’ permanent teeth was 31.79% (1 382/4 347). The prevalence was higher in males. Significant difference between the genders was observed (P<0.05). Tooth agenesis, the most frequent dental anomaly (15.00%, 652/4 347), was considerably common in females; supernumerary teeth (12.61%, 548/4 347) followed, which was significantly common in males. Both differences were statistically significant (P<0.05). The levels of prevalence of both microdontia and dilacerations were 4.00% (174/4 347) and 2.16% (94/4 347). The prevalence of cusp deformity, odontoma, and fused teeth were relatively low at 0.74% (32/4 347), 0.51% (22/4 347), and 0.39% (17/4 347), respectively. Conclusion The prevalence of teeth number and morphology abnormalities in children’s permanent teeth at the mixed dentition stage is apparently high. Tooth agenesis and supernumerary teeth are the most frequent. Panoramic radiograph is an efficient method for the early diagnosis of teeth number and morphology abnormalities. This method can assist pediatric dentists to formulate treatment plans for children at the appropriate time.
    Bacterial diversity in the oral cavity of adolescents with different caries susceptibilities
    Zhang Yangyang, He Jinzhi, Xu Xin, Zhou Xuedong
    West China Journal of Stomatology. 2015, 33(6):  602-606.  doi:10.7518/hxkq.2015.06.011
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    Objective To analyze the differences between the bacterial diversities in the saliva of caries-free and cariessusceptible adolescents through polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). Methods Twenty adolescent subjects aged 12-18 years were recruited and subdivided into two groups: caries-free adolescents (n=10) and caries-susceptible adolescents (n=10). Saliva samples were collected. Total DNA was isolated directly from each sample. A portion of the 16S rRNA gene locus was PCR-amplified by using universal primers. Microbial diversity was analyzed through PCR-DGGE. Results Analyzing the DGGE profile, we found that the composition of the saliva microbiome exhibited great intra-individual differences; the average band numbers of the caries-free adolescent group and the caries-susceptible adolescent group were 32.5±3.7 and 27.3±3.4, respectively. The differences between the groups were statistically significant (P=0.008). Shannon-Wiener’s indexes of the caries-susceptible adolescent group and the caries-free adolescent group were 2.5±0.2 and 2.6±0.2, respectively, but the differences between the groups were not significant (P=0.405). Clustering analysis results suggested that most of the samples in the same group clustered together; this observation showed a high community structure similarity. Conclusion The microbial diversity and complexity of bacteria in saliva are significantly higher in caries-free adolescents than in caries-susceptible adolescents. During caries development, bacterial diversity in the saliva likely decreases.

    Cloning, expression, and purification of c-di-AMP metabolism-related genes from Porphyromonas gingivalis
    Qiu Wei, Cheng Xingqun, Zhou Xuedong, Li Yuqing
    West China Journal of Stomatology. 2015, 33(6):  607-612.  doi:10.7518/hxkq.2015.06.012
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    Objective To clone, express, and purify cyclic diadenosine monophosphate (c-di-AMP) metabolism-related genes from Porphyromonas gingivalis (P. gingivalis) ATCC33277. Methods Polymerase chain reaction (PCR) from the genome of P. gingivalis ATCC33277 amplified the coding regions of pgn0523, pgn1187, and pgn2003 genes. The amplified DNA fragments were ligated with a prokaryotic expression vector pET28a to construct the recombinant expression plasmids pET-pgn0523, pET-pgn1187, and pET-pgn2003. These recombinant plasmids were transformed into Escherichia coli ( E. coli) BL21 (DE3) competent cells. The expression of recombinant proteins was induced by isopropyl-β-D-thiogalactoside and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were purified using a Ni2+ matrix column, and their concentrations were determined by a BCA Protein Quantitative Kit. Results The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 were amplified successfully with the correct molecular size. The recombinant expression vectors were constructed by ligating enzyme-digested PCR products and pET28a vector, and verified by PCR and sequencing. After induction and purification, recombinant proteins were expressed successfully and obtained with the correct molecular size (19.5×103, 39.9×103, 66.0×103). The final protein concentrations were 0.708, 0.523, and 0.861 mg·mL-1 after dialysis. Conclusion The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 are cloned successfully, and their coding products are expressed correctly in E. coli. Highpurity proteins are finally obtained. The cloning and purification of these important proteins will help us to further investigate the physiological function and regulatory mecha-nism of c-di-AMP signaling system in P. gingivalis.
    Effect of glutaredoxin on oxidative stress of umbilical vein endothelial cell exposed to Porphyromonas gingivalis lipopolysaccharide
    Shen Daonan, Cheng Wei, Jia Yue, Zhao Lei, Wu Yafei
    West China Journal of Stomatology. 2015, 33(6):  613-616.  doi:10.7518/hxkq.2015.06.013
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    Objective This study measures the glutaredoxin (Grx) gene and protein expression in umbilical vein endothelial cells upon exposure to Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). The involvement of the Aktsignaling pathway is also determined. Methods EA-hy926 cells were pretreated with 1 000 ng·mL-1 P. gingivalis LPS for 4, 12, 18, and 24 h, and then real-time reverse transcription polymerase chain reaction was employed to detect Grx1 expression. The effect of Grx on Akt activity was investigated using Western blot for the control, LPS (1 000 ng·mL-1 LPS), and carmustine (BCNU) groups (1 000 ng·mL-1 LPS, and the EA-hy926 cells were pretreated with 25 μmol·mL-1 BCNU for 30 min). Results Gene expression of Grx1 significantly increased in LPS group compared with that in the control group. The Grx1 expression reached the peak level in 12 h, and the variation between the expression in 4 and 12 h was significant (P<0.05). After 12 h, the protein levels of Grx and phosphorylated-Akt (p-Akt) significantly increased in the LPS group (P<0.05), whereas the BCNU group showed a considerable decrease in both Grx and p-Akt expression levels (P<0.05). Moreover, a slight difference was observed in the total Akt protein levels in the three groups (P>0.05). Conclusion Grx expression increased upon exposure of EA-hy926 cells to the LPS. Akt activity could be inhibited by BCNU (a Grx inhibitor), which indicated that Akt might act as a downstream regulator of Grx.
    Effect of specific sequence oligodeoxynucleotide MT01 on the proliferation, apoptosis, and cell cycle of osteoblasts invaded by Porphyromonas gingivalis
    Yu Haijiao, Shen Yuqin, Liu Yin, Gao Han, Zhou Yue, Hu Tianqi, Lin Chongtao
    West China Journal of Stomatology. 2015, 33(6):  617-621.  doi:10.7518/hxkq.2015.06.014
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    Objective This aimed to investigate the effect of specific sequence oligodeoxynucleotide MT01 on the biological properties of osteoblasts invaded by Porphyromonas gingivalis (P. gingivalis ) by evaluating proliferation, cell cycle, and apoptosis. Methods MG63 osteoblasts were recovered and incubated with MT01, CpG ODN, metronidazole (MNZ), and gentamicin (GEN) for 3 h. P. gingivalis (the multiplicity of infection was 100∶1) was added subsequently and cocultured for another 24 and 48 h. Cells with PBS comprised the blank group, whereas cells with P. gingivalis comprised the negative controls. Six experimental groups were established: PBS group, P. gingivalis group, MT01+P. gingivalis group, CpG ODN+ P. gingivalis group, MNZ+P. gingivalis group, and GEN+P. gingivalis group. The proliferative ability was measured by methyl thiazolyl tetrazolium assay, and the percentages of apoptosis and cell cycle were examined by flow cytometry. Results Compared with the blank group, proliferation increased significantly in the MT01+P. gingivalis group (P<0.05). The ratio of cells was lower at the G1 phase and higher at the S phase in the MT01+P. gingivalis group compared with the results in the P. gingivalis group (P<0.05). Early cell apoptosis in the MT01+P. gingivalis group was significantly lower than that in the P. gingivalis group (P<0.05). Conclusion MT01 can promote the proliferation, reduce the ratio of the G1 phase, increase the ratio of the S phase, and inhibit the early apoptosis of osteoblasts invaded by P. gingivalis.
    Effects of YAP-small interfering RNA on the proliferation and apoptosis of human periodontal ligament stem cells
    Tang Cuizhu, Wen Yong, Gu Weiting, Zhang Bing, Zhang Yunpeng, Ji Yawen, Xu Xin,
    West China Journal of Stomatology. 2015, 33(6):  622-626.  doi:10.7518/hxkq.2015.06.015
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    Objective To investigate the effects of small interfering RNA (siRNA) targeting YAP on the proliferationand apoptosis of human periodontal ligament stem cells (hPDLSCs). Methods Synthesized sequences of siRNA were transfectedinto hPDLSCs by LipofectamineTM 2000. The expression of YAP was identified by using real-time quantitative reversetranscription-polymerase chain reaction (RT-PCR) and Western blot analysis. Proliferation activity was detected by usingcell counting kit-8 (CCK-8). Changes in the cell cycle and apoptosis rate were detected by using flow cytometry. Resultswere analyzed by using SPSS 19.0, and P<0.05 was considered statistically significant. Results Expression of YAP mRNAand protein were significantly downregulated after 48 h of transfection (P<0.001). No obvious difference was found in theexpression levels of YAP protein between 48 and 72 h, thus indicating that siRNA could inhibit the expression of YAPpersistently and effectively. Proliferation activity was inhibited, and apoptosis rate was increased. Cell cycle was changedas the proportion of G1 and S phases increased (P<0.01) and G2 phase decreased (P<0.05). Conclusion Knocking down YAP gene by siRNA could inhibit proliferation activity,induce apoptosis, and change the cell cycle of hPDLSCs.Thus, YAP could regulate the proliferation and apoptosisof hPDLSCs.
    Canonical Wnt signaling pathway of the osteogenic differentiation of human periodontal ligament stem cells induced by advanced glycation end products
    Wu Yan, Deng Chao, Yang Kun, Cui Xiaoxia, Liu Qi, Jin Yan
    West China Journal of Stomatology. 2015, 33(6):  627-632.  doi:10.7518/hxkq.2015.06.016
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    Objective The effect of advanced glycation end products (AGEs) on the osteogenic differentiation of human periodontal ligament stem cells(hPDLSCs) was discussed. Changes in the Wnt signaling pathway during glycation were also determined. Methods In vitro tissue explanting method was primarily applied. Limiting diluted clone was cultured to obtain hPDLSCs in vitro. The subjects were divided into two groups: the healthy group (N-hPDLSCs) and the AGEs-stimulating group (A-hPDLSCs). Osteoblast mineralization was induced in the experimental groups. The following processes were performed: alizarin red staining; alkaline phosphatase (ALP) staining; real time polymerase chain reaction (real time PCR) for detecting osteogenic genes and Wnt classical pathway-related factors, DKK-1 and β-catenin; Western blot analysis. Bone protein and β-catenin were correlated in the nuclear expression. Results The cells were osteogenically induced. ALP staining showed that the N-hPDLSCs displayed the deepest color. Alizarin red staining indicated that the A-hPDLSCs group had less calcified nodules than the N-hPDLSCs group. The real time PCR results suggested that the expression of relative osteogenic genes in A-hPDLSCs was quite low. Statistically significant differences in differentiation were found between groups (P<0.05). The Western blot result was similar to that of real time PCR. Classical Wnt signaling pathway-related factor β-catenin was higher in A-hPDLSCs than in N-hPDLSCs. By contrast, DKK-1, which is an inhibitor in the Wnt pathway, had a significantly lower expression rate in A-hPDLSCs than in N-hPDLSCs. The Western blot result also showed that β-catenin expression in the nucleoprotein in A-hPDLSCs was notably higher than in N-hPDLSCs. Conclusion AGEs can inhibit hPDLSCs osteogenic differentiation. AGEs induce changes in the normal periodontal ligament stem cells classical Wnt pathway. Canonical Wnt pathway is reactivated because of AGEs stimulation.
    Changes in bone marrow mesenchymal stem cells osteogenesis by the regulation of Lnk/stem cell factor-cKit signaling
    Li Hao, Zhou Hailun, Wang Qi, Li Wei
    West China Journal of Stomatology. 2015, 33(6):  633-637.  doi:10.7518/hxkq.2015.06.017
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    Objective Changes in the osteogenesis of diabetic rat bone marrow mesenchymal stem cells (BMSCs) by the regulation of Lnk/stem cell factor (SCF)-cKit signaling were investigated. Methods BMSCs were isolated from diabetic rats and identified by immunocytochemical staining. These cells were divided into the control group (untransfected group), negative control group (transfected with control plasmid), and RNA interference group (transfected with Lnk-targeting RNA interference plasmid). Western blot was performed to analyze the effect of interference. The BMSCs were induced for osteogenic differentiation under diabetic conditions, and Western blot was used to examine the expressions of Lnk, SCF, and cKit in Lnk/SCFcKit signaling and osteogenic proteins alkaline phosphatase (ALP), osteocalcin (OCN), and collagen type Ⅰ a1 (ColIa1). Results Isolated cells expressed CD44 and CD90 but not CD11b or CD45. This phenomenon was characteristic of BMSCs. Compared with other diabetic BMSCs, cells in the RNA interference group expressed low Lnk but high SCF and cKit (P< 0.05). Thereafter, 28 days after induction of osteogenic differentiation, cells in the RNA interference group expressed low Lnk but high SCF, cKit, ALP, OCN, and ColIa1 compared with other diabetic BMSCs (P<0.05). Conclusion The inhibition of Lnk expression and activation of SCF-cKit pathway may improve the osteogenic differentiation of BMSCs under diabetic conditions.
    Effect of Al2O3 sandblasting on the bond strength between 3mol% yttrium-stabilized tetragonal zirconium polycrystal zirconia framework and veneering porcelain
    Zeng Qiang, Li Ning, Zhou Yanan, Yan Jiazhen, Liu Wenbo
    West China Journal of Stomatology. 2015, 33(6):  638-641.  doi:10.7518/hxkq.2015.06.018
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    Objective The effect of sandblasting on the bond strength between 3mol% yttrium-stabilized tetragonal zirconium polycrystal (3Y-TZP) zirconia framework and veneering porcelain was evaluated. Methods A total of 21 specimens [ (25±1) mm× (3±0.1) mm× (0.5±0.05) mm] were prepared according to ISO 9693. The specimens were then randomly divided into 3 groups. Sandblasting was performed on 2 meshes of Al2O3 particles: group A with mesh 110 and group B with mesh 80. Group C, which was not sandblasted, was the control group. The surface roughness of the zirconia framework, as well as the bond strength between 3Y-TZP zirconia framework and veneering porcelain, was measured. The interface microstructure was observed by scanning electron microscope (SEM), and elemental distribution was detected by energy dispersive spectroscopy (EDS). Results Surface roughness values were (1.272±0.149) μm for group A, (0.622±0.113) μm for group B, and (0.221±0.065) μm for group C. Statistical significance were found among groups (P<0.05). The bond strength values were (28.21±1.52) MPa for group A, (27.71±1.27) MPa for group B, and (24.87±3.84) MPa for group C. Statistical significance was found between group A and group C (P<0.05), whereas the other groups had no statistical significance (P>0.05). Interface adhesion failure was the primary performance. SEM images showed the close interface bonding, and EDS showed that the interface had no obvious element penetration. Conclusion Al2O3 sandblasting can slightly enhance the bond strength between zirconia framework and veneering porcelain.
    Translucency of dental zirconia ceramics sintered in conventional and microwave ovens
    Jiang Yuemei, Yang Ying, Zhan Wenhui, Hu Guoxin, Yang Qiuxia
    West China Journal of Stomatology. 2015, 33(6):  642-645.  doi:10.7518/hxkq.2015.06.019
    Abstract ( 642 )   HTML ( 3 )   PDF(pc) (1024KB) ( 534 )   Save
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    Objective To evaluate the effect of microwave sintering on the translucency of zirconia and to compare these effect with those of conventional sintering. The relationship between the microstructure of specimens and translucency was investigated. Methods A total of 10 disc-shaped specimens were fabricated from 2 commercial brands of zirconia, namely, Zenostar and Lava. Each group included 5 discs. Conventional sintering was performed according to the manufacturers’ specifications. The maximum temperature for Zenostar was 1 490 ℃, whereas that for Lava was 1 500 ℃. The dwelling time was 2 h. The sintering temperature for microwave sintering was 1 420 ℃, heating rate was 15 ℃·min-1, and dwelling time was 30 min. After sintering, the translucency parameter (TP) of the specimens were measured with ShadeEye NCC. The sintered density of the specimens was determined by Archimedes’ method. The grain size and microstructure of the specimens were investigated by scanning electron microscopy. Results Density and translucency slightly increased by microwave sintering, but no significant difference was found between microwave and conventional sintering (P>0.05). Small and uniform microstructure were obtained from microwave sintering. The mean TP of Lava was significantly higher than that of Zenostar (P< 0.001). Conclusion The translucency of zirconia sintered by microwave sintering is similar to that of the zirconia sintered by conventional sintering.
    Corrosion resistant properties of different anodized microtopographies on titanium surfaces
    Huo Fangjun, Xie Li, Tong Xingye, Wang Yueting, Guo Weihua, Tian Weidong,
    West China Journal of Stomatology. 2015, 33(6):  646-650.  doi:10.7518/hxkq.2015.06.020
    Abstract ( 666 )   HTML ( 5 )   PDF(pc) (1285KB) ( 782 )   Save
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    Objective To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. Methods Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. Results Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. Conclusion Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.
    Research progress on the relationship between Porphyromonas gingivalis and oral squamous cell carcinoma
    Wu Wuchao, Wu Yafei, Zhao Lei
    West China Journal of Stomatology. 2015, 33(6):  651-655.  doi:10.7518/hxkq.2015.06.021
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    Substantial evidence supports the relationship between chronic inflammation and cancer development. Numerous studies suggest that chronic inflammatory disease, such as periodontitis, contributes to head and neck squamous cell carcinoma development. Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial regions. Porphyromonas gingivalis, one of the most important pathogens in association with periodontal disease, might have a potential correlation with OSCC. Along with the development of molecular biological techniques, the association between Porphyromonas gingivalis and OSCC has been greatly emphasized in recent years. This review summarizes the association between these variables and the potential mechanisms involved in such relationship.
    Study progress of dental pulp stem cells in tissue engineering
    Shi Shiyu, Xie Jiamin
    West China Journal of Stomatology. 2015, 33(6):  656-659.  doi:10.7518/hxkq.2015.06.022
    Abstract ( 574 )   HTML ( 10 )   PDF(pc) (762KB) ( 850 )   Save
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    In recent years, modern tissue engineering is becoming emerging and developing rapidly, and the acquisition, cultivation and differentiation of seed cells is the premise and foundation of the construction of tissue engineering, so more and more scholars pay attention to stem cells as seed cells for tissue engineering construction. Dental pulp stem cells (DPSCs) is a kind of adult stem cells derived from dental pulp, and as a new kind of seed cells of tissue engineering, the study of DPSCs presents important significance in tissue and organ regeneration. In this review, we introduced the progress of studies on dental pulp stem cells and discussed their clinical application prospects.
    Keratocystic odontogenic tumor with malignant transformation: a case report
    Xu Laiqing, Zheng Guangning, Luo Jingjing, Wu Hongbing, Liu Yuanyuan, Guo Wenhao
    West China Journal of Stomatology. 2015, 33(6):  660-662.  doi:10.7518/hxkq.2015.06.023
    Abstract ( 748 )   HTML ( 6 )   PDF(pc) (1160KB) ( 823 )   Save
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    The keratocystic odontogenic tumor (KCOT) is a common cystic lesions of jaw, which has a high recurrence rate but rarely undergo malignant transformation. This study reported a patient with primary intraosseous squamous cell carcinoma developed from KCOT.
    Dermoid cyst in the floor of the mouth with tongue fistula: a case report
    Wu Pingfan, Lei Zhenge, Wu Jian, Chen Linlin
    West China Journal of Stomatology. 2015, 33(6):  663-664.  doi:10.7518/hxkq.2015.06.024
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    Dermoid cysts in the floor of the mouth with tongue fistula are unusual lesions. This study reported a case of dermoid cyst in the floor of the mouth with tongue fistula, analyzed the causes of such formation, and discussed the appropriate diagnosis and treatment methods by reviewing relevant literature.