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Objective: Periodontitis is a group of inflammatory diseases caused by microorganisms. Porphyromonas gingivalis, a gram-negative bacteria, is strongly associated with the onset of periodontitis. Tumor necrosis factor (TNF) receptor--associated factor 6 (TRAF6) represents an important target in the regulation of many disease processes, including immunity, inflammation, and osteoporosis. The aim of this study was to investigate the role of TRAF6 for inflammatory response in P gingivalis-infected human periodontal ligament cells (HPDLCs). Method and Materials: HPDLCs were stimulated with 1 × 108 CFU/mL P gingivalis, or 10 μg/mL P gingivalis lipopolysaccharide (LPS), separately in the absence or presence of small interfering RNA (siRNA) for TRAF6. The expression of TRAF6 was examined by real-time polymerase chain reaction and Western blot analysis. Concentrations of IL-1β, IL-6, and IL-8 in the culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA). Results: In this study, we found that both P gingivalis and its LPS treatment increased the expression of TRAF6 and proinflammatory cytokine production in HPDLCs. In addition, we used siRNA for TRAF6, and the inhibition of TRAF6 expression reduced the production of proinflammatory cytokines in HPDLCs stimulated with P gingivalis and its LPS. Conclusion: The results suggested that TRAF6 may be a key molecule to control proinflammatory cytokine production induced by P gingivalis and its LPS. TRAF6 suppression may inhibit inflammatory responses in HPDLCs infected by P gingivalis and its LPS. [ABSTRACT FROM AUTHOR]

Microbe infection is not only the key pathogenic factor of primary endodontic infectious diseases, but also the arch--crimina of endodontic treatment fail. Therefore, the endodontic treatment success is based on the debridement of infectious root canal, elimination of bacteria, and the prevention of endodontic reinfection. It is beset with difficulties to control the endodontic infection in clinic because of the bacterial variety, anatomic complexity of root canal, and limitation of the root canal therapeutic methods. In order to get the ideal prognosis of the root canal treatment, in the procedure of the therapy, it should be the tight isolation of tooth, reasonable choose of the root canal preparation technique, rational use of root canal preparation instrument, effective irrigation of root canal, proper root canal dressing, and the 3-dimensional obturation of root canal. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of root canal preparation treated by endodontists of different levels in different difficulty associated with the root canal anatomy factors. Methods Totally 422 teeth with 901 root canals were randomly selected from the Conservative Dentistry Department, West China Stomatology Hospital, and these teeth were respectively treated by junior specialist postgraduates, senior specialist postgraduates and endodontic specialists. Grading criteria of root canal risk factor and root canal therapy difficulty assessment were found based on 6 items: Tooth type, working length, root curvature, calcification, number of canals, and the previous endodontic treatment. The effects of root canal preparation with different difficulty in different groups were analyzed with RxC Chi-square test. Results Success rates of root canal preparation in junior group and senior group during three difficulty groups were statistically different (P<0.05), and the root canal therapy difficulty group I >group II > group HI. The operator factors in root canal therapy difficulty group I and group II were not significantly different (P>0.05). But in root canal therapy difficulty group DI, the endodontic specialist group have highest success rate in root canal preparation. Conclusion The cases of root canal treatment should be treated by endodontist of corres-ponding level according to the difficulty. In difficult cases, endodontic specialist can provide better root canal prepa-ration result. [ABSTRACT FROM AUTHOR]

Incidence rate of single root canal in maxillary second molar is very low. The emergence of curved single root canal in maxillary second molar with single root is especially rare. A case of curved single root canal in maxillary second molar with single root was successfully treated and reported in this article. This report also highlighted the role of cone beam computed tomography as an objective method to confirm the three-dimensional anatomy of teeth. [ABSTRACT FROM AUTHOR]

This case presents vertical root fracture with vital pulp in mandibular right first molar. Examinations of the history, clinical tests, laser Doppler flowmetry, and radiographs revealed that the tooth showed positive response to electric pulp testing and was normal compared with the healthy control tooth. This study aimed to use a novel vital preserving surgical technique (microapical surgery and nanometer bioactive materials) to make an effective therapeutic decision for the vital tooth with vertical root fracture.

The essence of pulp and periapical disease is bacterial infection. Thus, satisfactory infection control is the premise and foundation of healing, in which root canal preparation is a critical procedure. Root canal system anatomy, infection degree, physical cutting during root canal preparation, and certain cleaning measures affect the quality of infection control. Appropriate evaluation of the grades of infected root canals before treatment is necessary because different grades of root canal infection demand various disinfection schedules to facilitate tissue healing and guarantee the long-term success rate of endodontic treatment.

This study aims to evaluate the effect of neoadjuvant chemoradiotherapy (NCRT) on perioperative immune function during surgery to treat resectable locally advanced esophageal cancer. Records were retrospectively analyzed for 220 patients with locally advanced esophageal cancer, of whom 112 received surgery alone and 98 received neoadjuvant NCRT plus surgery. The two groups were compared in terms of proportions of CD3+, CD4+, CD8+, and natural kill (NK) cells, as well as the ratio of CD4+ to CD8+ cells. These measurements were made using flow cytometry on preoperative day 1 and on postoperative days 1 and 7. Subgroup analysis were performed in terms of degrees of pathological response of NCRT. When the entire NCRT and no-NCRT (surgery alone) cohorts were compared, no significant differences in propocrtions of CD3+, CD4+, CD8+, or NK cells or in the CD4+/CD8+ ratio occurred at any of the three time points. Similar results were obtained using the subgroup of NCRT patients who were NCRT-sensitive, but the subgroup of NCRT-insensitive patients showed significantly lower CD4+ and NK proportions and lower CD4+/CD8+ ratio than the no-NCRT group. Our findings suggest that NCRT does not affect perioperative immune function in patients who are NCRT-sensitive, but it does significantly reduce such function in patients who are NCRT-insensitive., (© 2016 International Society for Diseases of the Esophagus.)

Objective: Periodontitis is a group of inflammatory diseases caused by microorganisms. Porphyromonas gingivalis, a gram-negative bacteria, is strongly associated with the onset of periodontitis. Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) represents an important target in the regulation of many disease processes, including immunity, inflammation, and osteoporosis. The aim of this study was to investigate the role of TRAF6 for inflammatory response in P gingivalis-infected human periodontal ligament cells (HPDLCs)., Method and Materials: HPDLCs were stimulated with 1 x 108 CFU/mL P gingivalis, or 10 ug/mL P gingivalis lipopolysaccharide (LPS), separately in the absence or presence of small interfering RNA (siRNA) for TRAF6. The expression of TRAF6 was examined by real-time polymerase chain reaction and Western blot analysis. Concentrations of IL-1B, IL-6, and IL-8 in the culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA)., Results: In this study, we found that both P gingivalis and its LPS treatment increased the expression of TRAF6 and proinflammatory cytokine production in HPDLCs. In addition, we used siRNA for TRAF6, and the inhibition of TRAF6 expression reduced the production of proinflammatory cytokines in HPDLCs stimulated with P gingivalis and its LPS., Conclusion: The results suggested that TRAF6 may be a key molecule to control proinflammatory cytokine production induced by P gingivalis and its LPS. TRAF6 suppression may inhibit inflammatory responses in HPDLCs infected by P gingivalis and its LPS.

Objective: To isolate and characterize the side population cells (SP cells) in the lung adenocarcinomas cell line A549., Methods: The protein expression of ABCG2 in human lung adenocarcinoma cell line A549 was detected by immunohistochemistry. SP and NSP cells in the cell line A549 were isolated by FACS, and their differentiation was analysed. ABCG2 expression in the two cell subsets was detected by RT-PCR. The cell growth curves, cell division indexes, cell cycles, plate clone formation tests, migration and invasion assays, chemotherapeutic susceptibility tests, tests of the intracellular drug levels, and the tumor cell implantation experiments on nude mice were applied to study the biological properties of the two cell subsets. The expression of ABCG2 in the transplanted tumor in nude mice was detected by immunohistochemistry and RT-PCR., Results: The positive rate of ABCG2 expression in the A549 cells by immunohistochemistry was 2.13%. SP and NSP cells were isolated by FACS. The SP cells could produce both SP and NSP cells, while NSP cells only produced NSP cells. SP cells expressed ABCG2, but NSP cells did not. The proliferation and migration abilities of the two cell subsets were similar, but the invasion and tumorigenic ability of SP cells was significantly higher than that of NSP cells. The susceptibilities to DDP and its intracellular levels of the two cell subsets were similar, but the susceptibilities to 5-FU, VP16, NVB and GEM and their intracellular levels of NSP cells were significantly higher than those of the SP cells., Conclusions: SP cells in the human lung adenocarcinomas cell line A549 is enriched with tumor stem cells. An effective way to get lung adenocarcinomas stem cells is to isolate SP cells by FACS.

Objective: To evaluate the antibacterial efficacy of KaVo KEY laser on Enterococcus faecalis (E. faecalis) within infected root canals and roots surface in vitro., Methods: Fifty single-rooted teeth were selected, and infected root canals and roots surface vitro models were prepared. Then, these specimens were divided into three groups. First group were untreated as blank control. The other two groups were the laser groups: Irradiated 15 s and 30 s respectively with 80 mJ and 140 mJ in root canals and on roots surface. Microbiological samples were collected from root canals and roots surface at two time points (before irrigation and immediately after irrigation). The dentin chips from three different zone of part of root canals in each group were immediately collected and were cultured for 24 h in brain heart infusion (BHI)., Results: The number of E. faecalis in root canal and root surface in each of the groups were effectively reduced (P < 0.05), and there was no significant difference between each two groups (P > 0.05). Compared with the blank control, the bacterial number in 100 microm of dental tubules decreased after specimens treated with 80 mJ, and the experimental group irradiated 15 s was a significant decease (P < 0.05). The other groups were no changed in different zone of dental tubules., Conclusion: KaVo KEY laser is effective on sterilizing infected root canals and roots surface. It has also significant effect on bacterial in superficial dental tubules with low energy and short time.

Objective: To investigate the anatomic feature of the canal isthmus of mandibular permanent incisors by Micro-CT., Methods: Thirty-three mandibular permanent incisors with two canals were selected through the radiograph in proximal view. These teeth were then scanned using Micro-CT and reconstructed. The scanning layer thickness was 20 microm. We observed the apical 6 mm of the 33 roots, and 300 sections were gained each tooth, giving a total of 9900 sections. The numbers of canals at each level in the apical 6 mm were recorded. The numbers of sections showing isthmuses at each level of the root canals were recorded too. Data were analyzed using the Chi-square statistic to test the null hypothesis that location of the sections in each of the apical 6 mm and presence of the isthmus were independent. The minimum root canal wall thickness was measured in each of the apical 6 mm of the roots., Results: Isthmuses were found to be present at all levels with prevalence from 10.0% to 85.5%. The Chi-square test indicated a significant difference in the distribution of isthmuses with section (P = 0.0O1). The incidence of isthmuses was higher at the apical 3-6 mm level, and the highest incidence (85.5%) was at 5 mm level. There were many more sections containing complete isthmuses (49.7%) than those containing partial isthmuses (4.5%). The thickness of the minimum root canal was less than 0.5 mm., Conclusion: The mandibular incisors have a high incidence of isthmus and are narrow in proximal direction. Debridement of the isthmus is a major challenge during surgical and nonsurgical root canal treatment.

Objective: To investigate into the signaling pathway of Porphyromonas gingivalis (P. gingivalis) on cytokine expression in human dental pulp cells (HDPC)., Methods: Anaerobic method was employed to culture P. gingivalis, and then HDPC were intracellularly infected by P. gingivalis. The extraction of total RNA, real-time quantitative polymerase chain reaction (qPCR) and enzyme linked immunosorbent assay (ELISA) was used for mRNA expression of Nods and Rip2, protein secretion of interleukin-6 (IL-6)., Results: HDPC expressed Nods, Rip2 mRNA and IL-6. The up-regulation of Nods and Rip2 mRNA started after P. gingivalis infection, reached maximal level at 2 h, and then decreased at 6 h; whereas elevated IL-6 was found when P. gingivalis infected., Conclusion: P. gingivalis activate host innate immune responses in HDPC, and induce IL-6 production through Nod/Rip2-mediated signaling pathway.

Objective: To establish a model of intracellular infection of human dental pulp fibroblast (HDPF) by Porphyromonas gingivalis in vitro., Methods: HDPF was incubated with live Porphyromonas gingivalis with a multiplicitas of infection (MOI) from 100 for 0.5, 1.0, 2.0 hours. HDPF infected with live Porphyromonas gingivalis were observed by inverted microscope. Metronidazole, Penicillin, Streptomycin were added to the medium to kill any extracellular bacteria. Then the cells were lysed by sterile distilled water, dilutions of the lysates of cells were cultured anaerobically. Colony of invasive bacteria were then observed. HDPF exposed live Porphyromonas gingivalis with a MOI 50 and 100 for 1.0 hour, then cells survival rate were detected by MTT assay., Results: After infected with Porphyromonas gingivalis 2.0 hours, cells were eumorphism. Porphyromonas gingivalis of incubation for 1.0, 2.0 hours was invasive cells. MTT assays indicated 99.07% cells survival rate with a MOI from 50 and 74.43% cells survival rate with a MOI from 100., Conclusion: A model of HDPF intracellular infection with Porphyromonas gingivalis was successfully established in vitro.

Objective: To evaluate the shaping ability of two nickel-titanium rotary systems (ProTaper and Hero642) in simulated S-shaped canals., Methods: Thirty simulated S-shaped canals were randomly divided into three groups and prepared by ProTaper, Hero642, ProTaper combined with Hero642 respectively. All the canals were scanned before and after instrumentation, and the amount of material removed in the inner and outer wall and the canal width after instrumentation were measured with a computer image analysis program., Results: There was significant difference in the amount of material removed at the inner side of apical curvature and outer side of apex between ProTaper combined with Hero642 and ProTaper files (P < 0.05) at the same tip size. The inner and outer wall of the canals were evenly prepared by ProTaper combined with Hero642, and the taper of canals were better than those prepared by Hero642., Conclusions: ProTaper combined with Hero 642 had better shaping ability to maintain the original shape and could create good taper canals in the simulated S-shaped canal model.

Objective: To investigate the effect of canal curvature on measured precision in canal length of human lower mandibular permanent incisors imaged by direct digital radiograph., Methods: With Trophy digital X-ray system, 299 Chinese lower mandibular permanent incisors were selected to take the direct digital X-ray photography in both facial to lingual (L-T) and proximal directions (M-D). Two operators familiar with endodontic knowledge estimated the canal length by means of on-screen DDR with 2-and 3-click measurements., Results: The true canal length of Chinese lower mandibular permanent incisors was (19. 54 +/- 1.62) mm. The tooth root canal length on digital image was overestimated with 3-click measurement (P < 0.05), and the canal length with 2-click measurement was almost similar to the true canal length from the facial-lingual direction X-ray photography (P > 0.05). The less than 1 mm difference between the estimated canal and the true canal length was above 95%. The canal length was underestimated with 2-click measurement as the curvature severity increased., Conclusion: Direct digital radiography system is applicable to estimate the canal length in clinic as the accuracy is very good. The curved canal length should be estimated with 3-click measurement.

Objective: To identify morphological features of cross-sectioned root canal in Chinese mandibular permanent incisors., Methods: Twenty mandibular permanent incisors were selected in this study. The tooth roots were embedded in resin and transversely sectioned with a low-speed diamond saw. The number of root canal and the morphology and isthmus of the root canal were observed under a stereo-microscope, which included the measure of the canal diameter., Results: The double root canal comprised 22.5%, 30.0%, and 15.0% in crown third, middle third, and apical third root canals of the mandibular permanent incisors, respectively. The long oval canal comprised 44.8%, 77.0%, and 44.5% in crown third, middle third, and apical third root canals, respectively. The canal isthmus comprised 62.5%, 75.0%, and 48.7% in crown third, middle third, and apical third root canals, respectively. The diameter of buccal-lingual canal was at least 2 times of the diameter of mesial-distal canal., Conclusion: The cross-sectioned root canal morphology in Chinese mandibular permanent incisors varies considerably. But most have long oval and canal isthmus, which imposes a great challenge for root canal therapy.

Objective: To study the effect of concentrations of glucose on the initial adherence of Streptococcus mutans (S. mutans) to saliva-coated hydroxyapatite (SHA), and to compare the initial adherence of S. mutans from caries-active group with that of S. mutans from caries-free group., Methods: Each 10 clinical isolates of S. mutans from caries-active and caries-free subjects were used in this study. And S. mutans UA159 was also included in this experiment. SHA was used to simulate tooth surface in oral cavity. S. mutans clinical isolates and strain UA159 were cultured in TPY liquid medium containing 3H-TdR in the same radioactive concentration and glucose in 0.2%, 1.0%, 5.0% concentration. Then grown cells were harvested to produce a suspension. SHA and radiolabelled bacterial suspension (A550(nm) = 0.52) were mixed for 90 minutes, samples were assayed by using liquid scintillation counter, and binding abilities of strains were evaluated by the count per minute (CPM)., Results: The initial adherence ability of S. mutans from caries-active group was higher than that of S. mutans from caries-free group (P < 0.05). And the initial adherence ability of S. mutans cultured in different concentration of glucose was also significantly different (P < 0.05), 5.0% glucose group had the highest adherence ability, and 0.2% glucose group had the lowest adherenceability., Conclusion: (1)Difference of the initial adherence of S. mutans might relate to difference of carious experiences; (2) Glucose may play an important role in S. mutans initial adherence, to some extent, S. mutans cultured in the higher concentration of glucose has the higher initial adherence property.

Purpose: To assess the difficulty of root canal therapy in Chinese permanent maxillary anterior teeth by radiographic methods in vitro., Methods: 80 maxillary anterior teeth including 27 maxillary central incisors, 22 maxillary lateral incisors and 31 maxillary canines were collected and X-rayed in 3 individual directions: labiopalatal projection, mesiodistal projection and the maximal angle shot. Three anatomic risk factors: root curvature, calcification and working length of root canal therapy were assessed by difficulty assessment standards and criterions. Kruskal-Wallis test was used to analyze the data., Results: The results showed that the root canal therapy of 2 and 3 were significantly more difficult than 1, P < 0.05; while there was no significant difference between 2 and 3, P > 0.05. In 1, the results of difficulty assessment of root canal therapy were significantly different among 3 individual X-rays which were projected from 3 different directions (P < 0.05). The difficulty caused by root curvature was significantly greater than calcification and working length in labiopalatal X-ray in 1 (P < 0.05) and 2 (P < 0.01), while there was no significant difference among these 3 risk factors in 3 in labiopalatal projection (P > 0.05)., Conclusions: The results suggest that the labiopalatal X-rays can be safely regarded as the reliable projection shot for difficulty assessment before endodontic procedures. Root curvature was by far the most important risk factor that affected the difficulty of root canal therapy in 1 and 2 while root curvature, calcification and working length played the same roles in root canal therapy of 3.

Objective: To compare the shaping ability of ISO standard stainless steel K files and multi-taper ProTaper nickel-titanium files in simulated resin curved root canals. METHODS Thirty simulated resin root canals were randomly divided into three groups and prepared by stainless steel K files, hand ProTaper, rotary ProTaper, respectively. The amount of material removed from inner and outer wall and canal width after canal preparation was measured, while the canal curvature before and after canal preparation and canals aberrations were recorded., Results: The stainless steel K files removed more material than hand ProTaper and rotary ProTaper at the outer side of apex and inner side of curvature (P < 0.05). The mean degree of straightening in stainless steel K files group was significantly bigger than in ProTaper group (P < 0.05). The canals prepared by ProTaper had no evident aberration., Conclusion: The shaping ability of ProTaper is better than stainless steel K files.

Objective: To investigate the root canal curvature in Chinese mandibular permanent incisors., Methods: Two hundred and ninety nine Chinese mandibular permanent incisors were included in this study. The root canals were inserted with stainless steel 15# K files, and then taken radiography from the facial and proximal view by X-ray paralleling technique. Canal curvatures were evaluated by measuring the angle, the radius of the curvatures, and the length of the curved part of the canal. Based on the curved angle and the shape of curved canals, the root canals were classified., Results: The curved angle, radius, and the curved canal length was 5.28 degrees +/- 5.52 degrees, 16.19 mm +/- 12.38 mm, 4.10 mm+/-2.01 mm, respectively in the facial view; 9.99 degrees +/- 5.84 degrees, 18.86 mm +/- 9.71 mm, 3.27 mm +/- 2.39 mm, respectively in the proximal view. The prevalence of straight, light, moderate, and serve curved root canals in mandibular permanent incisors was 15.7%, 66.9%, 16.7%, and 0.7%, respectively (P<0.05) based on the curved angle. The prevalence of straight, L shape, and S shape curved root canals was 7.7%, 50.5%, and 41.8%, respectively (P < 0.05)., Conclusion: Most of the root canals in mandibular permanent incisors are curve.

Purpose: To detect the distribution of P. gingivalis and B. forsythus in the infected root canals from Chinese chronic apical periodontitis, and investigate the colonization relationship between them in the root canals., Methods: P. gingivalis and B. forsythus in the root canal samples of thirty-eight teeth with chronic apical periodontitis from 31 subjects who were referred to the Sichuan University West China Dental Hospital for dental treatment were studied with a 16S rDNA-directed polymerase chain reaction method. Fisher's exact tset was used to detect B. forsythus in the infected root canals with or without P. gingivalis. OR was used to analyse the relationship between them., Results: The prevalence in 38 teeth was 39.5% for P. gingivalis, and 26.3% for B. forsythus, respectively. Significant positive relationship was shown in the combination of P. gingivalis and B. forsythus (OR=12, P<0.05)., Conclusion: Both P. gingivalis and B. forsythus colonized in the root canals with chronic apical periodontitis and there was a positive relationship between P. gingivalis and B. forsythus in the infected root canal flora.

Objective: To evaluate the clinical quality of root canal therapy (RCT) in West China Dental Hospital of Sichuan University., Methods: 1 423 RCT teeth were finished from Mar. 2001 to Feb. 2002 in West China Dental Hospital. Root canal filling quality and treatment period of these teeth were evaluated. 695 teeth of the total were revisited 2 years later and 2-year success rate were evaluated., Results: The ratios of adequate filling, underfilling, and overfilling were 79.97%, 14.62% and 5.41%, receptively. Full canal RCT ratio of molar was 89.44%. Average RCT treatment period was 2.8 weeks. 2-year success rate of RCT was 94.39%., Conclusion: Clinical RCT level of West China Dental Hospital was satisfactory from 2001 to 2002.