Objective　To evaluate the clinical outcome of bone grafts in combination with dental implants in jaw defects caused by tumor or trauma. Methods　From 2007 to 2012, 11 cases of jaw defects caused by trauma or tumor resection were reconstructed by bone grafts combined with dental implants. Function and esthetics of the patients were followed up and evaluated. Results　All the bone survived after bone grafts. Forty-one implants were embedded and all succeeded except 2 cases involving 4 implants that suffered from implant gingivitis. All the other cases received excellent function and maxilla-facial figure. Conclusions　Functional reconstruction by bone grafts in combination with dental implants is effective for patients with jaw defects. Transplant of keratinized gingiva around the implants may help the implants adapt friction and maintain the health of peri-implant mucosa.

Abstract: Objective To detect the expression pattern of embryonic stem cell (ESC) markers in human periodontal ligament stem cells (PDLCs). Methods PDLCs were isolated from human periodontal ligament tissue, and characterized by multipotent differentiation and cell surface analysis. Immunocytochemistry and RT-PCR were performed to detect the expression of ESC markers (Oct4、Nanog、Sox2、SSEA-4、TRA-1-60、TRA-1-81) in PDLCs. Results PDLCs exhibited typical fibroblast-like morphology, and could differentiate into osteoblasts and chondroblasts. PDLCs homogenously expressed mesenchymal markers of CD44, CD90 and CD105, but heterogenously expressed CD146 and Stro-1. Part of ESC markers was detected in PDLCs. Oct4, Nanog, SSEA-4 and TRA-1-60 were positive in PDLCs while Sox2 and TRA-1-81 were negative. Semi RT-PCR demonstrated similar expression of Oct4 and Nanog in PDLCs of Passage 3 and 8. However, sox2 were negative at the mRNA level. Conclusion Besides mesenchymal stem cells markers, PDLCs could also express parts of ESC markers, which is of certain application value to the identification and purification of periodontal ligament cells.

Objective To investigate the effect of TiO2-NPs, on the osteoblasts and attempt to elucidate the damage response pathways and molecular mechanism to provide scientific basis for developing the new titanium-based implantation. Methods To establish a co-culture system of MC3T3-E1 cells and TiO2-NPs to study the cytotoxic effect of TiO2-NPs on the osteoblasts, the Oxidative stress reaction, apoptosis and possible molecular mechanism. Results The results demonstrated that TiO2-NPs could decrease MC3T3-E1 cells viability, trigger oxidative stress, and activate the p53/bax/bcl-2 -mediated pathway to regulate the apoptosis of osteoblasts. Conclusion TiO2-NPs could cause osteoblasts cytotoxicity in dose-dependent manner and cause oxidative stress reaction and P53 regulated apoptosis. These data demonstrated that TiO2-NPs might have a negative impact on the osteoblasts and provide a theoretical basis to evaluate the biosafety of TiO2-NPs for the design of future materials for implantation.

Objective To investigate expressions of genes in osteoblast-like cells derived from bone marrow stem cells (BMSCs) transfected with chitosan nanocarrier containing plasmid-BMP-2 sequences (CNPBs). Methods According to different concentrations of plasmid–BMP-2 (pBMP-2), CNPBs experimental groups were divided into CPB50 concentration group (50 μg/mL pBMP-2), CPB100 concentration group (100 μg/mL pBMP-2) and CPB200 concentration group (200 μg/mL pBMP-2) respectively. Expression levels of specific molecules (Alkaline Phosphatase, ALP; Osteoprotegerin, OPG; Osteocalcin, OC; Osteopontin, OPN) in osteoblast-like cells were detected and analyzed. Results There were higher expression levels of ALP, OPG, OC and OPN genes in osteoblast-like cells in CNPBs groups than control groups, especially in CBP200 group. Conclusion Expression levels of genes in osteoblast-like cells derived from BMSCs transfected with CNPBs can be promoted effectively.

Objective To evaluate the value of cone-beam computed tomography (CBCT) in the diagnosis of vertical root fractures (VRF). Methods Sixty-seven teeth suspected of VRF from 61 patients underwent periapical radiograph (PR) and CBCT. Then all subjects underwent surgical operation and direct visualization to confirm the presence or absence of VRF. The results were compared and analyzed statistically. Results Surgical operations confirmed the presence of VRF in 62 teeth. The positive rate, sensitivity and accuracy of VRF according to CBCT were 83.6%、90.3% and 91% respectively, while those of PR were 31.3%、33.9% and 38.8%, respectively（P＜0.01）. The sensitivity of CBCT for VRF in buccolingual and mesiodistal direction were 93.2% and 62.5%, which were higher than those of PR (69.6% and 12.8%)（P＜0.05）. Conclusions CBCT appears to be more accurate than PR in the diagnosis of VRF.

Objective To introduce and evaluate one kind of novel cementing technique of implant restoration in the esthetic zone. Methods 60 cases of anterior cemented implant restorations were included. The cement margins of these restorations were located 1 to 1.5 mm under gingival margin. A novel cementing technique was introduced in experimental group while conventional cementation technique was applied in the control group. mSBI, PD and cementation failure rate were recorded and evaluated 1 month and 6 months respectively after cementation. Results 1 month after cementation, the mSBI of experimental group was statistically lower than that of control group, while no statistically significant difference was found in other parameters. 6 months after cementation, there was no statistically significant difference in any parameters between two groups. Conclusion The special cementation technique is helpful to reduce the possibility of periimplantitis caused by excess cement in the early phase and to enhance the gingival health.

Abstract: Objective To observe the apical microleakage with simplified rotary ProTaper preparation method and to evaluate the sealing ability of the root apex. Methods Sixty extracted human teeth were randomly divided into two groups. In the experimental group, the root canals of 30 teeth were prepared with simplified rotary ProTaper method and obturated by 0.06 taper gutta percha cones with vertical condensation technique. In the control group, the root canals of 30 teeth were prepared with 0.02 taper stainless steel files in step-back technique and obturated by 0.02 taper gutta percha cones with cold lateral condensation technique. All specimens were penetrated by the line dye and the distances of dye penetration in the roots apical linear extent were measured. Results In the experimental group, the average value of the apical linear extent of dye penetration was 0.60mm with the standard deviation of 0.29 mm. In the control group, the average value of the apical linear extent of dye penetration was 1.18 mm with the standard deviation of 0.83mm. There was significant difference in apical microleakage between two groups (p<0.05). Conclusions The apical sealing effects of roots filled with simplified rotary ProTaper preparation method is better.

Objective A Preliminary test is to be performed to test the friction properties of monocrystal ceramic bracket and polycrystalline ceramic bracket compared with metal bracket of the same size. Methods The maximum static friction force and the average dynamic friction of monocrystal ceramic bracket, polycrystalline ceramic bracket and metal bracket combined with two kinds of metal arch-wires were tested by a universal testing machine. Results The friction produced by the combination of monocrystal ceramic bracket or polycrystalline ceramic bracket with two kinds of arch-wires was greater than the metal bracket. The metal bracket had smallest frictional force of three kinds of brackets. The monocrystal ceramic bracket had smaller frictional force than polycrystalline ceramic bracket. Conclusions The frictional force of monocrystal ceramic bracket and arch-wires is smaller than polycrystalline ceramic bracket，but is greater than metal bracket combined with arch-wires.

Abstract：0bjective To explore clinical effects of combining dental operating microscope with ultrasonic technique on treating difficult root canals. Methods 74 teeth of various kinds of 112 difficult root canals were selected and treated with Microscope and ultrasonic technique. The clinical effects and the success rate after six months were evaluated. Results：55 patients completed root canal therapy and got clinical success with 74.32% success rate; in terms of root canals, there were 81 successful root canal treatments with success rate of 72.32%. After six months the rate was 82.69%. The overall success rate was 60.56%. Conclusions Microscopic ultrasonic technology application provides an effective means for difficult root canal treatment.

Abstract： Objective To compare the sealability of the three root canal pastes: Vitapex paste、AH-Plus paste and GuttaFlow. Methods Thrity single rooted human teeth were chosen and randomly divided into three groups with 10 teeth in each group. Group A was filled with Vitapexas paste. Group B was filled with AH-Plus paste. Group C was filled with GuttaFlow. Section was done to each tooth 2,4,6,8 mm from root apexes. MIAS-2000 images were used to analyze and calculate the cross-sectional area of canal (AC) and perceentage of voild-filled area (PV). Record the results and make statistical analysis. Results The values of AC in three groups were different at the distance of 2,4,6,8 mm from root apexes but without statistical significance(P>0.05). PV value of group C was statistically different with those of the other groups 2,4,6,8 mm from root apexes (P<0.05). PV values of group A and B had statistical significance 2,4mm from root apexes (P<0.05), but those of group B and C had no statistical significance(P>0.05). PV value in each group 6,8 mm from root apexes had statistical significance (P<0.05). Conclusions GuttaFlow sealer and the AH-Plus sealer show higher density of root canal filling in various parts of the root canals; Vitapex sealer shows lower density of root canal filling.

Objective To observe the correction of Angle’s II1 malocclusion in growth and development stages with Twin-block appliances, and discuss the treatment mechanism. Methods Use Twin-block appliances for 18 cases of Angle’s II1 malocclusion in growth and development stages, 10 male and 8 female, 10 to 13 years old, with no history of malocclusion. Results After 20 to 24 months’ treatment, the 18 patients’ anterior tooth overbite, and covering relation were nearly normal, molar relationship was neutral, and lateral profile of soft tissue significantly improved. Conclusions Twin-block appliances have obvious effect on Angle’s II1 malocclusion in growth and development stages

Objective Semi-anatomic (20°) artificial teeth complete denture and non-anatomic (0°) artificial teeth complete denture were the common methods to repair the upper and lower dentition defect. We will observe and compare the masticatory function of the two types of complete denture. Methods 7（5 males&2 females） volunteered edentulous patients about 68.7 years old on average were selected for our study and two complete dentures of the same base, but different Posterior cusp inclinations (20°, 0°) were designed. The masticatory efficiency was measured by the Absorbance method on the day when patients wore the denture and the myoelectric manifestations of TA and MM were scanned after that. Results The mean masticatory efficiency of 0°complete denture is lower than 20°complete denture (P<0.05). The EMG activity of 0° group was more active than the 20° group when chewing peanut (P<0.05). The masticatory efficiency was in proportion to the TA, MM EMG activity. Conclusions When chewing food with certain hardness, better masticatory efficiency can be achieved with 20°complete denture and the work of the masticatory muscles can be easier.

Objective To investigate the facial aesthetic perception changes of patients who received orthodontic treatment, in order to instruct orthodontic treatment to improve satisfaction. Methods A panel of 100 orthodontic patients from Shandong University Stomatology Hospital evaluated sets of four post-treatment standardized photographs (one frontal, one frontal smiling, one lateral and one frontal occlusal ) of 12 orthodontic patients, in relation to the pre-treatment sets of the same patient, on a five-point scale before their orthodontic treatment and after one year and a half. Results were statistically analyzed. Results The facial aesthetic perception of patients who received orthodontic treatment improved significantly. Among the patients, the facial aesthetic perception of the middle-aged female patients with a higher level of education improved most significantly while the lower-educated young male patients’ facial aesthetic perception did not improve significantly. Both extraction and non-extraction patients' facial aesthetic perception have improved, but there was no significant difference. Conclusions The patient's aesthetic perception will improve with the going on of orthodontic treatment. We should pay attention to the changes in patient's aesthetic psychology and behavior in orthodontic treatment, adjust the treatment program timely and accordingly, and to enhance communication with patients to improve patients’ satisfaction.

Objective To investigate the public oral medical institutions in Liaoning Province in 2011, and to analyze the status of the dental manpower in public medical institutions in Liaoning Province. Methods A mass survey on dental manpower was made in registered public oral medical institutions in Liaoning Province in 2011 by means of questionnaire given out by administrative departments, which included the number, structure, composition，distribution，equipment of dental manpower in public medical institutions in Liaoning Province. Results There were 506 public dental medical institutions including 16 tertiary hospitals, 96 secondary hospitals, 394 primary hospitals with 2485 dentists, 773 nurses, 416 technicians and 2242 dental chairs in Liaoning. 76.58% of the dental manpower were young and middle-aged staffs. 35.57% of the dentists were attending doctors, 43.5% of them had bachelor degree and 59.76% of the dentists majored in general dentistry. The majority of the dental auxiliaries had primary title. 58.60% of the nurses majored in general dentistry and 49.94% of the nurses had college degree. 40.63% of the technicians majored in prosthetic dentistry and 65.14% of them had secondary school education or below. The ratio of the dentists to nurses to technicians was 6:2:1. The ratio of the nurses to dental chairs was 1:2.9. The ratio of the prosthetic dentists to technicians was 1.67:1. Conclusions The composition and distribution of dental manpower are not reasonable in public medical institutions in Liaoning Province, and dental auxiliaries are relatively in shortage. We should rationally readjust the distribution and strengthen effective utilization of oral health resources in public oral medical institutions in Liaoning Province.