Objective The purpose of this study was to explore the efficacy of low level laser treatment (LLLT) combined with initial periodontal therapy in treating chronic periodontits.Methods Eighteen patients with chronic periodontitis were randomly treated in a spit-mouth design with combination of laser (808 nm,80 mW) treatment with scaling and root planing (experimental) or with scaling and root planing alone (contol) after OHI and supragingival cleaning.Clinical parameters of sulcus bleeding index (SBI),periodontal probing depth (PD) and clinical attachment loss (CAL) of both sides were recorded and gingival crevicular fluid samples were collected at baseline and 1,4,12 weeks after the treatment.GCF samples were analyzed for b-FGF,IL-1β,IL-8 level using ELISA assay.Results For the change of SBI and PD,only SBI in the experimental group experienced significant reduction (P＜0.05) at 1 week compared with baseline (P＜0.05),and the reduction in both groups were statistically significant (P＜0.05) at 4 weeks.The same situation occurred while both experimental groups made more significant difference (P＜0.01) at 12 weeks.The reduction of SBI was obvious in both groups when the PD was more than 6 mm.For CAL,the experimental group showed signs of improvement (P＜0.05) at 4 weeks; both groups indicated improvement (P＜0.05),while the experimental was more significant (P＜0.01) at 12 weeks.For the levels of b-FGF,it showed steady rise after treatment in experimental group,while it went up to the baseline after falling in control group.At 12 weeks,there were statistical significance of differences between two groups (P＜0.05).The changes of IL-1β and IL-8,in the experimental group showed better results than that in control group,while the difference between two groups was not significant (P＞0.05).Conclusion LLLI can accelerate the healing of periodontal tissue by reducing the SBI,decreasing the PD,improving the CAL and increasing levels of b-FGF in the GCF of the patients.

Objective To explore the effect of preservation of inclined fractured permanent molars by transverse fixation with screw post,and provide a practical method for reserving the inclined fractured permanent molars.Methods Clinical data of 50 patients with inclined fractured permanent molars by transverse fixation with screw post in the Department of Stomatology of Tianjin First Central Hospital between January 2010 to December 2011 were reviewed retrospectively.After fixing the crown with steel-wire binding and root canal treatment,the molars were drilled a hole buccolingually and placed screw post.The flowable light-curing composite resin was used to seal the crack and bond screw post to prevent the relative movement.All treated molars were restored with full crown.All patients were followed up for 10-60 months.The therapeutic effects were observed.Results After 5 year-follow-up,41 cases were cured completely,6 cases were cured clinically,and 3 cases failed treatment.Conclusion The transverse fixation with screw post and bonding technique can preserve the inclined fractured molars to gain chewing function and avoid or reduce the extraction of affected teeth,which provides a better restoration effect.

Objective To investigate the influence of perioperative continuing aspirin therapy on tooth extraction surgery in elderly patients with coronary heart disease.Methods A total of 926 patients with coronary heart disease who required tooth extraction were enrolled in this study.Among them,241 patients discontinued aspirin therapy before tooth extraction,685 patients continued aspirin therapy before tooth extraction.The entering rate of operation was evaluated.100 patients continuing aspirin and 100 patients discontinuing aspirin were randomly selected.Systemic pressure,diastolic pressure and heart rate before and after tooth extraction were detected.100 matched healthy elderly patients were selected as normal control group.Multivariate logistic regression analysis was used to estimate the risk for tooth extraction.Results The entering rate of operation was 67.9％ (131 cases) in 193 patients with angina pectoris discontinuing aspirin therapy and 82.1 ％ (312 cases) in 380 patients with angina pectoris continuing aspirin therapy (x2 =14.77,P＜0.01).The entering rate of operation was 41.7％ (20 cases) in 48 patients undergoing coronary revascularization and discontinuing aspirin therapy,and 80.7％ (312 cases) in 305 patients undergoing coronary revascularization and continuing aspirin therapy (x2=33.95,P＜0.01).The changes in systolic blood pressure before versus after dental extraction had a significant difference between the discontinuing aspirin group and control group [(15.9±5.5) mmHg vs.(12.2±4.7)mmHg,P＜0.05,1 mmHg=0.133 kPa],while had no significant difference between the continuing aspirin group and control group [(13.6±4.5) mmHg vs.(12.2±4.7) mmHg,P＞0.05].There were no significant differences in changes in diastolic blood pressure and heart rate in the intraoperative period between the patients and controls (P＞0.05).The bleeding rate in patients continuing aspirin therapy was not significantly different as compared with control group (P＞ 0.05).Multivariate logistic regression analysis revealed that perioperative discontinuing aspirin therapy remained the second significant risk factor for tooth extraction.Conclusions Preoperative administration of aspirin should be continued in dental extraction surgery in elderly patients with coronary heart disease.

Objective To investigate the effective endodontic irrigation protocols on smear layer removal from curved canals. Methods Forty extracted mandibular first molars with curved mesial root canal were selected and decoronat-ed. Mesiobuccal root canal was instrumented to F3 using handed ProTaper system, and randomly divided into four groups ac-cording to final irrigation protocols: syringe irrigation (group A), #30K file agitation (group B), passive ultrasonic irrigation (PUI, group C) and combination of #30K file agitation and PUI (group D). The ultrasonic file was located within 0.5 mm coro-nal from start of the curvature. All root canals were mesio-distally split, snicked at the start of the curvature and 2 mm apical-ly from the start of the curvature, and divided into three sections. They wereⅠ,ⅡandⅢfrom coronal to apical. The smear layer of each section of root canal was examined under scanning electron microscope (SEM). Results Group D presented small amounts of scattered or thin smear layers and obtained the lowest score at each section of root canal wall. At sectionⅠandⅡ, there was no significant difference in smear layer score between group D and group C. The smear layer scores were both significantly lower in group D and group C than those of group A and group B (P<0.05). At sectionⅢ, the smear layer score was significantly lower in group D than that of group A, group B and group C, and which was significantly lower in group B and group C than that of group A (P<0.05). Conclusion When ultrasonic file was located coronal from the start of the curvature, K file, which was the same size as dimension of apical portion preparation to agitate and PUI can remove smear layer from curved canals efficiently.

Objective To generate the erythroid differentiation associated gene(EDAG) knockout mice and analyze their sensitivity to low dose radiation-induced damage.Methods Zinc finger nuclease technology ( ZFNs ) was used to produce the EDAG knockout mice.The low dose radiation-induced damage was evaluated by peripheral blood cell counts, DNA damage and colony formation of bone marrow cells.Wild-type and EDAG knockout mice were irradiated with 0.31 Gy/min X-ray, one minute per day for seven consecutive days, and the cumulative radiation dose was 2.17 Gy(n=7).The blood cell counts were measured by an automated hemocytometer.DNA damage was detected by immunofluorescence assay with a DNA damage marker p-H2A.x antibody (n=3).The colony formation ability of bone marrow cells was evaluated with a semi-solid culture medium(n=3).Results A model of EDAG knockout mice was established.Compared to wide type mice, white blood cell counts of EDAG knockout mice decreased significantly while the DNA damage marker p-H2A.x expression was increased on the third day after X-ray irradiation.The ability of colony-forming was reduced after 7 days of X-ray irradiation.Conclusion Our present study found that EDAG knockout mice are more sensitive to low dose radiation-induced damage as shown by decreased peripheral blood cells counts, reduced colony-forming ability of bone marrow cells, and increased DNA damage.These results suggest that EDAG knockout mice can serve as a powerful tool for evaluation of the biological effects of low-dose radiation damage.

Objective To evaluate the effects of root canal cleanliness on the fracture resistance of roots filled with AH-Plus. Methods Eighty single canal premolars were instrumented using step-back technique, then were randomly di-vided into four groups (n=20 for each group). Group A was washed with distilled water for 10 min, group B1 was washed with 5%EDTA for 1 min, group B2 was washed with 5%EDTA for 5 min and group B3 was washed with 5%EDTA for 10 min. Ten samples of each group were observed by scanning electron microscope at the coronal, middle and apical thirds to exam-ine smear layer removal. The remaining samples of each group were fixed into a electronic universal testing machine and ver-tically loaded until fracture. Results The difference of coronal and middle thirds was significant between group B3 and group B2 (P<0.05). At the middle third, there was significantly improved efficiency in smear layer removal in group B2 than that of group B1(P<0.05). The mean fracture resistance was significantly higher in group B3 (391.91±12.82)N than that of group B2 (335.54±16.14)N, group B1(296.47±17.82) N and group A (264.77±16.64)N (P<0.05). Group B2 showed a signifi-cantly better fracture resistance than that of group B1 and group A (P<0.05). Conclusion The complete removal of root ca-nal smear layer can significantly improve the fracture resistances of roots filled with AH-Plus.

OBJECTIVETo construct a GFP/Puro double-labeled lentiviral expression vector for CK8 silencing and assess the effects of CK8 silencing on cell apoptosis.

METHODSThe siRNA sequences of CK8 were inserted into the lentiviral expression vector GV248 and transfected into 293T cells with the packaging plasmids PMD and SPA. The lentivirus was collected at 24 and 36 h post-transfection. Flow cytometry was used to detect the virus titer and the positive cells were selected with puromycin. The knockdown of CK8 was examined by Western blotting. The effect of CK8 down-regulation on cell apoptosis induced by cisplatin was detected with Annexin V/PI staining.

RESULTS AND CONCLUSIONWe successfully constructed CK8 interference lentiviral vector and obtained a stable cell line with CK8 knock-down that was sensitive to cisplatin-induced apoptosis.

Apoptosis ; Cell Line ; Down-Regulation ; Genetic Vectors ; Humans ; Keratin-8 ; genetics ; Lentivirus ; Plasmids ; RNA Interference ; RNA, Small Interfering ; Transfection

Objective To construct a GFP/Puro double-labeled lentiviral expression vector for CK8 silencing and assess the effects of CK8 silencing on cell apoptosis. Methods The siRNA sequences of CK8 were inserted into the lentiviral expression vector GV248 and transfected into 293T cells with the packaging plasmids PMD and SPA. The lentivirus was collected at 24 and 36 h post-transfection. Flow cytometry was used to detect the virus titer and the positive cells were selected with puromycin. The knockdown of CK8 was examined by Western blotting. The effect of CK8 down-regulation on cell apoptosis induced by cisplatin was detected with Annexin V/PI staining. Results and Conclusion We successfully constructed CK8 interference lentiviral vector and obtained a stable cell line with CK8 knock-down that was sensitive to cisplatin-induced apoptosis.

Objective To explore the correlation between psychological health status and pressure perception , sleep quality of community residents .Methods By multistage sampling method ,1 471 community residents of Lixia District in Ji′nan were surveyed by pressure perception scale , Pittsburgh sleep quality index and Kessler psychological scale .Results The score of psychological health acquired ( 19.29 ±6.62 ) , and 66.2%community residents existed different level psychological health issues , community residents with different educational background , occupation , family monthly income had statistical significance of differences in psychological health (t=5.345,2.765,8.245, -2.808;P <0.05).The total score of community residents pressure perception was (17.06 ±5.47)and the total score of sleep quality index was (4.73 ±3.09);the pressure perception had positive correlation with psychological health and sleep quality (r=0.627,0.332;P<0.01);the total score of sleep quality had positive correlation with psychological health (r =0.441, P <0.01).The hierarchical regression analysis showed the sleep quality played a part of mediation between pressure perception and psychological health , which mediation effect was 0.15, and the relative intermediary effect was 24.2%. Conclusions The pressure perception can impact psychological health directly , and also can indirectly affect psychological by sleep quality . Sleep quality can release pressure perception caused negative effects of psychological health and protect community residents′psychological health .

Objective To construct a GFP/Puro double-labeled lentiviral expression vector for CK8 silencing and assess the effects of CK8 silencing on cell apoptosis. Methods The siRNA sequences of CK8 were inserted into the lentiviral expression vector GV248 and transfected into 293T cells with the packaging plasmids PMD and SPA. The lentivirus was collected at 24 and 36 h post-transfection. Flow cytometry was used to detect the virus titer and the positive cells were selected with puromycin. The knockdown of CK8 was examined by Western blotting. The effect of CK8 down-regulation on cell apoptosis induced by cisplatin was detected with Annexin V/PI staining. Results and Conclusion We successfully constructed CK8 interference lentiviral vector and obtained a stable cell line with CK8 knock-down that was sensitive to cisplatin-induced apoptosis.