The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe func-tional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional （3D） reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the compu-ter, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate diagnosis and treatment of maxillary tumor; (2) Maxillary reconstruction with free fibula flap used computer assisted techniques; (3) Computer assisted orbital floor reconstruction after maxillectomy. The results suggested that computer assisted techniques could significantly improve the clinical outcome of maxillary reconstruction.

Objective： To construct a novel biomimetic calcium phosphate (BioCaP) scaffold loaded with bone morphogenetic protein-2 (BMP-2), and to investigate its role in the osteogenesis of human adipose-derived stem cells (hASCs) in vitro and in vivo. Methods: The BioCaP scaffold coprecipitated with BMP-2 (BMP-2-BioCaP) was constructed in this study. Field emission scanning electron microscopy (SEM) was used to analyze the morphology of the surfaces. The release kinetics was measured to evaluate the slow-release characteristics in vitro. BMP-2-BioCaP was immersed in proliferation medium (PM) or osteogenic medium (OM), respectively. The supernatants were collected and used to culture hASCs in vitro. Cell numbers were determined using the cell-counting kit-8 (CCK-8) to assess the cell proliferation. After 7 and 14 days, alkaline phosphatase (ALP) staining and quantification were performed to test the activity of ALP. After 14 and 21 days, the calcification deposition was determined by alizarin red S (ARS) staining and quantification. The expressions of the osteoblast-related genes were tested on day 4 and day 14. In the in vivo study, 6 nude mice were used and implanted subcutaneously into the back of the nude mice for 4 groups: (1) BioCaP scaffold only, (2) BioCaP scaffold+hASCs, (3) BMP-2-BioCaP scaffold, (4) BMP-2-BioCaP scaffold+hASCs (test group). After 4 weeks of implantation, hematoxylin-eosin (HE) staining was performed to evaluate the in vivo osteogenesis of hASCs. Results: SEM observations showed that BioCaP and BMP-2-BioCaP scaffold were entirely composed of straight, plate-like and sharp-edged crystal units, and the length of the crystal units varied between 5 and 10 μm. Release kinetics analysis demonstrated that BMP-2 incorporated with BioCaP could be released at certain concentration and last for more than 21 days, and the accumulative protein release could reach 20%. CCK-8 assays showed that cell proliferation was not significantly affected by BMP-2-BioCaP. ALP activity was higher by the induction of OM+BMP-2-BioCaP than of the other groups (P<0.01). More mineralization deposition and more expressions of osteoblast-related genes such as Runt-related transcription factor 2 (RUNX2), ALP, osteopontin (OPN) and osteocalcin (OC) were determined in the OM+BMP-2-BioCaP group at different time points (P<0.01). HE staining showed that, in the test group and BMP-2-BioCaP scaffold group, the extracellular matrix (ECM) with eosinophilic staining were observed around hASCs, and newly-formed bone-like tissues could be found in ECM around the scaffold materials. Moreover, compared with the BMP-2-BioCaP scaffold group, more bone-like tissues could be observed in ECM with typical structure of bone tissue in the test groups. No obvious positive results were found in the other groups. Conclusion: BMP-2-BioCaP scaffold could achieve slow-release of BMP-2 and promote the osteogenic differentiation of hASCs in vitro and in vivo. The novel tissue-engineered bone composed of hASCs and BMP-2-BioCaPis promising for the repair of bone defect.

Objective： To compare the proliferative and periodontal specific differentiation abilities of induced pluripotent stem cells (iPSCs) at different passages, and to investigate whether long term culturing would have a negative influence on their proliferation and specific differentiation capacity, thus providing a theoretical basis for further in-depth research on periodontal regeneration and the possible clinical applications of iPSCs. Methods: IPSCs derived from human gingival fibroblasts at passages 5, 10, 15 and 20 were recovered and cultured in vitro. Their morphology and proliferation rates were observed respectively. We further induced the iPSCs at different passages toward periodontal tissue under the treatment of growth/differentiation factor-5 (GDF-5) for 14 days through the EB routine, then compared the periodontal differentiation propensities between the different passages of iPSCs by detecting their calcified nodules formation by Alizarin red staining and assaying their relative periodontal tissue related marker expressions by qRT-PCR and immunofluorescence staining, including bone related markers: osteocalcin (OCN), bone sialoprotein (BSP); periodontal ligament related markers: periostin, vimentin; and cementum related markers: cementum attachment protein (CAP), cementum protein 1 (CEMP1). The untreated spontaneous differentiation groups were set as negative controls respectively. Results: iPSCs at different passages all showed a high proliferative capacity when cultured in vitro and turned into a spindle-like shape similar to fibroblasts upon periodontal specific differentiation. All iPSCs formed typical calcified nodules upon GDF-5 induction by Alizarin red staining in comparison to their untreated controls. The relative calcium deposition at all passages had been significantly upgraded under the treatment of GDF-5 (P5: t=2.125, P=0.003; P10: t=2.246, P=0.021; P15: t=3.754, P=0.004; P20: t=3.933, P=0.002), but no significant difference in their calcium deposition were detected within passages 5, 10, 15 and 20 (periodontal differentiation: F=2.365, P=0.109; spontaneously differentiation: F=2.901, P=0.067). Periodontal tissue related marker expressions of iPSCs at all passages had also been significantly upgraded under the treatment of GDF-5 (P<0.05), but still, no significant difference in their expression levels of periodontal tissue related proteins were detected within passages (BSP: F=0.926 7, P=0.450; vimentin: F=0.917 1, P=0.455; CEMP1: F=2.129, P=0.1367). Conclusion: Our results preliminarily confirmed that long term culturing won’t influence the proliferation capa-city and periodontal specific differentiation propensity of iPSCs, as they can still proliferate and differentiate toward periodontal cells with high efficiency upon growth factor induction after continuous passaging. Therefore, iPSCs could be recognized as a promising cell source for future possible application in periodontal tissue regeneration.

Objective： To investigate the effect of occlusal interference on the energy metabolism of masticatory muscle by studying the changes of adenosine triphosphate (ATP), adenosine diphosphate (ADP), inosine monophosphate (IMP), phosphocreatine, creatine, lactate and pH level in masseter muscles of rats after occlusal interference. Methods: Fifty male Sprague-Dawley rats were randomly assigned into experimental group (n=40) and control group (n=10). In experimental group, 0.4 mm thick metal crown was cemented to the upper right first molar of the rat, and maintained for 3, 7, 10, 14 d separately (n=10 for each time point). No occlusal interference was applied for control group. Bilateral masseter muscles of all the rats were acquired under general anesthesia. The samples of 5 rats in each group were fully homogenized with 0.4 mol/L perchlorate (10 mL/g). The homogenates were centrifuged, filtered and analyzed for ATP, ADP, IMP, phosphocreatine, creatine and lactate content by high performance liquid chromatography. The other samples in each group were mixed with homogenates containing 5 mmol/L sodium iodoacetate (10 mL/g), then homogenized and measured for pH value by pH meter in thermostatic water bathunder 37 degrees centigrade. Results: Compared with control group, ATP content in bilateral masseter of the rats increased  3 d after occlusal interference ［right side：(5.36±0.13) μmol/g，left side：(5.77±0.25) μmol/g］ (P<0.05), and back to normal on 7, 10 and 14 d- There was an increase in IMP ［right side：(0.21±0.03) μmol/g，left side：(0.19±0.03) μmol/g］and creatine content ［right side：(24.76±2.94) μmol/g，left side：(27.75±2.23) μmol/g］in bilateral masseter of the rats  7 d after occlusal interference (P<0.05) and no difference was detected on 3, 10, and 14 . Phosphocreatine content in bilateral masseter started to decline  7 d after occlusal interference and maintained the low level on 10 and 14 d ［right side：(10.70±0.71) μmol/g, (11.57±0.52) μmol/g, (10.74±1.39) μmol/g, left side：(10.05±0.57) μmol/g, (10.75±1.12)μmol/g, (10.61±1.15) μmol/g］(P<0.05). No change of ADP, lactate or pH level in bilateral muscles of the rats after occlusal interference was observed (P>0.05).  Conclusion: Occlusal interference influences the content of energy metabolites in masticatory muscle of rats, which may be related to the pathological process of masticatory muscles induced by occlusal interference, such as muscle pain, dysfunction and altered fiber architecture.

Objective： To compare the extent and time course of alveolar bone loss and osteoclast activation in two murine models of periodontal disease: molar ligation and Porphyromonas gingivalis (P. gingivalis) oral inoculation. Methods: A splitmouth design was applied to two groups of mice (C57BL6, 6-8 weeks old, n=24 in both groups), resulting in four treatment groups: (1) Control group: unliga-ted upper right 2nd molars receiving CMC only, (2)Ligature group: ligation of a 9-0 suture around the upper left 2nd molar, (3) P. gingivalis group: unligated upper right 2nd molar receiving P. gingivalis challenge only, (4)Ligature + P.gingivalis group: ligation of the upper left 2nd molar in combination with oral inoculation with 109 colony-forming units(CFU) P. gingivalis. Alveolar bone loss was measured as the cementoenamel junction and alveolar bone crest (CEJ-ABC) distance. In the study, 48 C57BL6 mice were designed and treated as described above, and osteoclasts were counted on histological sections following tartrate-resistant acid phosphatase (TRAP) staining and counts were normalized to alveolar bone surface distance. Then 36 C57BL6 mice were investigated, of which 30 were ligated a 9-0 silk ligature around the 2nd molar in the left maxillary quadrant and 6 were not ligated. After ligation for 1 week, the ligatures in 12 mice were taken off for either 1 week or 2 weeks. The CEJ-ABC distance of the 6 mice without ligation was baseline. The CEJ-ABC distances were measured and analyzed. The data were analyzed with one-way ANOVA. Results: Molar ligation induced marked alveolar bone loss after 3, 6, 9 and 12 weeks ［(0.16±0.04) mm, (0.16±0.02) mm, (0.18±0.03) mm, (0.17±0.02) mm］, vs. corresponding controls ［（0.09±0.03）mm，（0.10±0.01）mm，（0.12±0.04）mm，（0.12±0.01）mm］ and P. gingivalis group ［（0.09±0.03）mm、（0.12±0.01）mm，（0.12±0.02）mm，（0.10±0.01）mm］， P<0.05.  Combined treatment with molar ligation and P. gingivalis did not further increase the CEJ-ABC distance. Evidence for osteoclast activation was found one day after molar ligation, and TRAP-positive cell numbers peaked on day 3 (12±4 vs. control 2±2, P<0.01). After taking off ligature following ligation for 2 weeks, it showed significantly regrowth of alveolar bone compared with that before removal of the ligature on day 7 ［（0.07±0.02）mm vs. （0.13±0.01）mm, P<0.01］. Conclusion: Molar ligation is a rapid and effective way to induce periodontal bone loss in mice. Osteoclast activation occurs within 24 hours of ligature placement, and the extent of bone loss well exceeds that of the P.gingivalis-induced bone loss. Removing ligature after periodontal disease might help bone regeneration by regrowth of the alveolar bone.

Objective： Concentrated growth factors (CGF), a new generation of platelet concentrate products, appears to have more abundant growth factors because of its special centrifugation process. However, there are few studies supporting this. This study was designed to evaluate the effect of CGFs in the treatment of Ⅱ° furcations of mandibular molars. Methods: In the present study, thirty-one Ⅱ° furcation involvements in twenty mandiblular molars were included and randomly divided into two groups. The furcation involvements in the experimental group were treated with bone graft therapy combined with CGFs, and the furcation involvements in the control group were treated with bone graft therapy alone. The clinical examination and cone beam computed tomography (CBCT) were performed at baseline and 1 year post-surgery for the two groups. The changes of clinical and CBCT data at baseline and 1 year post-surgery were compared between the experimental group and the control group. Results: At baseline, there were no significant differences between the two groups in the probing depth (PD), vertical clinical attachment loss (CAL-V) and horizontal clinical attachment loss (CAL-H): PD (7.36±2.32) mm (the experimental group) vs. (7.53±2.06) mm (the control group); CAL-V (8.69±1.65) mm (the experimental group) vs. (8.81±1.53) mm (the control group); CAL-H (5.24±2.01) mm (the experimental group) vs. (5.35±2.14) mm (the control group). At the end of 1 year post-surgery, the clinical parameters of both groups were significantly improved (P<0.001). For the experimental group, the average vertical attachment gain was (2.78±1.66) mm, and the vertical attachment loss was improved significantly compared with the baseline (P<0.001); the average horizontal attachment gain was (2.10±1.89) mm, and the horizontal attachment loss were improved significantly compared with the baseline (P<0.001). Furthermore, the improvement degree of the experimental group was significantly higher than that of the control group (P<0.001). At baseline, there were no statistical differences in the vertical bone loss (BL-V) or horizontal bone loss (BL-H) between the two groups (P>0.05): BL-V (5.08±2.17) mm (the experimental group) vs. (5.84±2.65) mm (the control group); BL-H (5.85±2.13) mm (the experimental group) vs. (6.01±2.27) mm (the control group). At 1 year post-surgery, both groups showed significant radiographic bone gain at vertical and horizontal directions compared with baseline (P<0.001). For the experimental group, the average vertical radiographic bone gain was (2.20±1.98) mm, the horizontal radiographic bone gain was (2.51±2.18) mm, the vertical and horizontal radiographic bone loss were both significantly reduced compared with the baseline (P<0.001). For the control group, the average vertical radiographic bone gain was (1.89±2.15) mm, the horizontal radiographic bone gain was (1.30±2.47) mm, the vertical and horizontal radiographic bone losses were both significantly reduced compared with the baseline (P<0.001). And the experimental group showed significantly higher bone gain at vertical and horizontal directions compared with the control group (P<0.001). Conclusion: Within the limitation of the present study, CGFs showed positive role in the treatment of Ⅱ° furcation involvements of mandibular molars.

Objective： To study the role of different scale structure of Ti implants on the biological behaviors of human umbilical vein endothelial cell (HUVECs) and to reveal the role of material surface topographical features on peri-implant angiogenesis. Methods: Titanium（Ti） discs with different surface structures (Ti discs with smooth surface, Ti discs with nano scale structure, Ti discs with micro scale structure and Ti discs with micro/nano scale structure, named as SM-Ti, Nano-Ti, Micro-Ti and Micro/nano-Ti, respectively) were prepared and their surface topographical features were confirmed via scanning electron microscopy (SEM) observation. HUVECs were cultured on these Ti discs. Biological outcomes of HUVECs on different surfaces were carried out, including cell adhesive capacity, proliferation, vascular endothelial growth factor (VEGF) production and intracellular expression of Ca2+. Results: The results of SEM images and immunofluorescence double staining of rhodamine-phalloidin and DAPI showed that compared with the SM-Ti and Nano-Ti group, the adhesive capacity and proliferation behavior of HUVECs on the surfaces of Micro-Ti and Micro/nano-Ti was decreased. The results of culturing HUVECs on different groups of Ti discs after 24 hours showed that the cells number grew from (18±4) to (42±6)/ vision on SM-Ti, (28±6) to (52±10)/vision on Nano-Ti, (20±4) to (21±6)/vision on Micro-Ti and (16±4) to (18±6)/vision on Micro/nano-Ti. Moreover, compared with the adhesion and proliferation of HUVECs on SM-Ti group and Nano-Ti, the adhesion and proliferation of  HUVECs on Micro-Ti group and Micro/nano-Ti group was significantly reduced (P<0.05).The results of enzymelinked immunosorbent assay (ELISA) showed that the VEGF productions of SM-Ti, Nano-Ti, Micro-Ti and Micro/nano-Ti were (690±35) ng/L, (560±20) ng/L, (474±43) ng/L and (517±29) ng/L, respectively. Moreover, compared with the VEGF production of HUVECs on SM-Ti group, the VEGF production of HUVECs on Micro-Ti group and Micro/nano-Ti group was significantly reduced (P<0.05). The results of Ca2+ ion detection showed that the Ca2+expression of HUVECs on Micro-Ti and Micro/nano-Ti was significantly higher than that on the surface of SM-Ti and Nano-Ti. These results implied that the over expressed Ca2+ might contributed to the impaired biological function of HUVECs on Micro-Ti and Micro/nano-Ti. Conclusion: Different topographical features on titanium influenced the biological behaviors of the HUVECs, which may illustrate how topographical features of Ti implant affect peri-implant angiogenesis. These results also suggest that the biological behaviors of HUVECs might be relative to the changed expression of intracellular Ca2+.

Objective： To investigate the feasibility of periodontal mechanical therapy for chronic periodontitis and coronary heart disease patients with low dose of aspirin. Methods: Sixty nine chronic periodontitis patients with coronary heart disease were randomly selected as the experimental group (medication group, group A), the control group (withdrawal group, group B) including 20 chronic periodontitis patients with coronary artery disease, stopping the drug for one week and another control group with 50 chronic periodontitis patients (group C). The three groups were examined with pocket probing, and received supragingival scaling, subgingival scaling, and root planning. Local bleeding after operation was observed. In 30 minutes after periodontal mechanical treatment, there was still a need to take some hemostatic measures (containing the oxidized cellulose putting in the periodontal pocket, gauze oppressing, and suturing). Nd:YAG laser was used to stop bleeding 60 minutes after operation. Results: At baseline, there was no significant difference in the three groups, as to the plaque index(PLI）, the probing depth (PD）, and the attachment loss (AL）. The bleeding index (BI）in group A was significantly higher than that in group C (P=0.024), higher than that in group B (P=0.088). The platelet maximum aggregation rate (Aggmax) was detected in some subjects. The average Aggmax value group A was 15.2%, which was much greater than that in group B (60.7%) and group C (62.5%). The three groups were all safe in the treatment of periodontal therapy. There were five cases of active bleeding in group A, one case in group B and one case in group C in 30 minutes after operation. In 60 minutes after operation, there was one case of bleeding actively in group A. Nd:YAG laser was used to stop bleeding successfully. Conclusion: The chronic periodontitis and coronary heart disease patients with longterm oral administration of low dose of aspirin can be safely treated with periodontal mechanical treatment, and the effect of local hemostasis is positive without stopping the drug.

Objective： To explore a new method for rapid extracting and rebuilding three-dimensional (3D) digital root model of vivo tooth from cone beam computed tomography (CBCT) data based on the anatomical characteristics of periodontal ligament, and to evaluate the extraction accuracy of the method. Methods: In the study, 15 extracted teeth (11 with single root, 4 with double roots) were collected from oral clinic and 3D digital root models of each tooth were obtained by 3D dental scanner with a high accuracy 0.02 mm in STL format. CBCT data for each patient were acquired before tooth extraction, DICOM data with a voxel size 0.3 mm were input to Mimics 18.0 software. Segmentation, Morphology operations, Boolean operations and Smart expanded function in Mimics software were used to edit teeth, bone and periodontal ligament threshold mask, and root threshold mask were automatically acquired after a series of mask operations. 3D digital root models were extracted in STL format finally. 3D morphology deviation between the extracted root models and corresponding vivo root models were compared in Geomagic Studio 2012 software. The 3D size errors in long axis, bucco-lingual direction and mesio-distal direction were also calculated. Results: The average value of the 3D morphology deviation for 15 roots by calcula-ting Root Mean Square (RMS) value was 0.22 mm, the average size errors in themesio-distal direction, the bucco-lingual direction and the long axis were 0.46 mm, 0.36 mm and -0.68 mm separately. The average time of this new method for extracting single root was about 2-3 min. It could meet the accuracy requirement of the root 3D reconstruction fororal clinical use. Conclusion: This study established a new method for rapid extracting 3D root model of vivo tooth from CBCT data. It could simplify the traditional manual operation and improve the efficiency and automation of single root extraction. The strategy of this method for complete dentition extraction needs further research.

Objective： To evaluate the clinical effect and safety of periodontal-orthodontic treatment in patients with aggressive periodontitis (AgP) and malocclusion. Methods: A retrospective analysis was conducted in 25 AgP patients, who had received periodontal-orthodontic treatment in Peking University School and Hospital of Stomatology. Clinical indexes, including probing depth (PD), bleeding index (BI) and percentage of sites with bleeding on probing (BOP%) were evaluated at three time points: Baseline (T0); active periodontal treatment finished and before orthodontic treatment (T1); and after orthodontic treatment (T2). Also changes of ratio of the residual alveolar bone height (RBH) and the occurrence of root resorption were evaluated by periapical radiographs. Results: (1) Compared with T0, all the clinical parameters including PD, BI, BOP% and percentage of sites with PD>3 mm were significantly improved (P<0.001). (2) Significant difference was observed in the average RBH between T0 (68.37%±15.60% and T2 (70.27%±14.23%). RBH in upper incisors ［(58.79%±16.71% at T0, 65.54% (55.74%, 78.13%) at T2］, upper canines ［77.62% (66.06%, 87-17%) at T0, 79.57% (69.75%, 86.52%) at T2］ and upper molars ［74.30% (61-69%, 84-45%) at T0, 76.76% (68.12%, 85.09%) at T2］ showed significant increase (P<0.05). (3) After orthodontic treatment, varying degrees of root resorption occurred in (23.94%±13.45%) of teeth per capita, among which the lower and upper incisors showed the highest incidence (68.48% and 65.31% in homogeneous teeth, respectively). Conclusion: After active periodontal treatment, orthodontic treatment in AgP patients had not aggravated inflammation and alveolar bone resorption; root resorption occurred in two-thirds of incisors approximately.

Objective： To observe mesial-distal bone morphology in classes Ⅱ and Ⅲ furcation involvements (FI) of mandibular molars using cone beam computed tomography (CBCT), to develop a classification system of mesial-distal bone morphology of furcation defects and to observe the intrabony defects  on CBCT images. Methods: Based on the existing CBCT data, the mandibular molars with horizontal bone defects in furcation area were observed. One hundred and seventeen sites of 81 mandibular molars with class Ⅱ or class Ⅲ FIclassified on CBCT images were included. The classification system of mesial-distal bone morphology of furcation defects was developed. According to the location of the line drawn from mesial to distal alveolar bone crest (AC-line) of the tooth and bone level under furcation fornix, the bone morphology was classified into three types, including concave type, flat type and protruding type. The concave type was divided into two subtypes according to the location of AC-line and furcation fornix (Fx), which were subtype 1（AC-line coronal or equal to Fx）and subtype 2 （AC-line apical to Fx).The frequency of each type was calculated and analyzed. The intrabony defects was observed on sagittal CBCT images. Results: In the 117 sites with FI, the flat type appeared with the highest rate (64.10%) and the protruding type appeared with the lowest rate (6.84%). The rates of subtype 1 and subtype 2 of concave type were 13.68% and 15.38%, respectively. The rate of subtype1 which was supposed to be beneficial for bone regeneration was 8.96% in class Ⅱ FI and 20.00% in class Ⅲ FI. Thirtyone intrabony defects were found among the 117 FI, 29 of which appeared in proximal aspect of the tooth and the left 2 appeared in furcation area. The highest frequency of the intrabony defects was found in subtype 1 of concave type. Conclusion: The classification of mesial-distal bone morphology on CBCT images may be helpful for clinicians to make accurate treatment plan before surgery and could be used in future studies to understand the influence of bone morphology on regenerative therapy for furcation defects.

Objective： To explore a new method of whole-process digital esthetic prosthodontic rehabilitation combined with periodontic surgery for complicated anterior teeth esthetic defects accompanied by soft tissue morphology, to provide an alternative choice for solving this problem under the guidance of threedimensional (3D) printing digital dental model and surgical guide, thus completing periodontic surgery and digital esthetic rehabilitation of anterior teeth. Methods: In this study, 12 patients with complicated esthetic problems accompanied by soft tissue morphology in their anterior teeth were included. The dentition and facial images were obtained by intra-oral scanning and three-dimensional (3D) facial scanning and then calibrated. Two esthetic designs and prosthodontic outcome predictions were created by computer aided design /computer aided manufacturing (CAD/CAM) software combined with digital photography, including consideration of white esthetics and comprehensive consideration of pink-white esthe-tics. The predictive design of prostheses and the facial appearances of the two designs were evaluated by the patients. If the patients chose the design of comprehensive consideration of pink-white esthetics, they would choose whether they would receive periodontic surgery before esthetic rehabilitation. The dentition design cast of those who chose periodontic surgery would be 3D printed for the guide of periodontic surgery accordingly. Results: In light of the two digital designs based on intra-oral scanning, facing scanning and digital photography, the satisfaction rate of the patients was significantly higher for the comprehensive consideration of pinkwhite esthetic design (P<0.05) and more patients tended to choose priodontic surgery before esthetic rehabilitation. The 3D printed digital dental model and surgical guide provided significant instructions for periodontic surgery, and achieved success transfer from digital design to clinical application. The prostheses were fabricated by CAD/CAM, thus realizing the whole-process digi-tal esthetic rehabilitation. Conclusion: The new method for esthetic rehabilitation of complicated anterior teeth esthetic defects accompanied by soft tissue morphology, including patient-involved digital esthetic analysis, design, esthetic outcome prediction, 3D printing surgical guide for periodontic surgery and di-gital fabrication is a practical technology. This method is useful for improvement of clinical communication efficiency between doctorpatient, doctor-technician and doctors from different departments, and is conducive to multidisciplinary treatment of this complicated anterior teeth esthetic problem.

Objective： To compare the effect of four different techniques on removal of vapor lock in the apical region of curved root canals. Methods: Forty simulated resin root canals with 45° curvature were prepared using WaveOne Primary, then the apical foramen were sealed with soft wax. The teeth were divided randomly into 4 groups thereafter (n=10). Contract solution was injected into the canals using a 30 G side-vented needle and scanned with cone-beam CT (CBCT) to identify the volume of the vapor lock. Four different techniques including photon-induced photoacoustic streaming (PIPS) laser-activated irrigation, gutta-percha cone technique, ultrasonic irrigation, and sonic irrigation were used to remove the vapor locks in the root canals. The residual volume of the vapor lock was identified again using CBCT scanning data. Accordingly, the reduction rates of the vapor lock were calculated. Furthermore, the initial and residual vapor lock length was calculated. The data were analyzed by using the One-Way ANOVA analysis and Kruskal-Wallis H test at a significance level of P<0.05. Results: There was no significant difference in the initial vapor lock volume (P>0.05). Residual volume of the vapor lock for PIPS laser-activated irrigation was 0 mm3, and that for gutta-percha cone technique was (0.02±0.07) mm3, significantly lower than those of ultrasonic and sonic irrigation, the values being (0.20±0.09) mm3 and (0.23±0.06) mm3 (P<0.001), respectively. The reduction rates of the vapor lock of PIPS laser-activated irrigation and gutta-percha cone technique were 100.00% (100.00%, 100.00%) and 100.00% (77.66%, 100.00%), respectively, significantly higher than those of ultrasonic irrigation ［70.37% (56.41%, 91.43%)］ and sonic irrigation ［63.54% (51.47%, 74.00%), P<0.001］. The length of the residual vapor lock for PIPS laseractivated irrigation was 0 mm, and that for gutta-percha cone technique was (0.15±0.47) mm, significantly lower than those of ultrasonic and sonic irrigation, values being (2.21±0.09) mm and (2.34±0.08) mm (P<0.001), respectively. The length of the residual vapor locks in the ultrasonic and sonic group remained approximately the same as the distance between the working tip and the apical foramen. Conclusion: PIPS laser activated irrigation and gutta-percha cone technique could remove the vapor lock from the apical region of curved canals effectively.

Objective： To analyze the accuracy of the digital imaging fiber optic transillumination (DIFOTI) on diagnosis of caries lesions depth using DIAGNOcam system. Methods: This experiment adopted self-matching design. Seventy-four extracted teeth (molar: sixty-six, premolar: eight) with one caries lesions in proximity which were not damaged in surface marginal ridge were selected. Dental calculus and dental stains were removed from the extracted teeth for standby application. A sign was marked in the middle of the occlusal surface edge at the side of decay. Then the teeth were fixed in the standard model of dentition and cavities were adjacent with the sound tooth surface. Sticky wax was applied to seal the level of 2 mm beyond cemento-enamel junction (CEJ) in the direction of occlusion and interproximal space to imitate gingival margin and gingival papilla. The standard models of dentition was seated in imitation head mold. The lesions depth degree was looked into and checked with DIAGNOcam system. Besides, the pictures on the occlusal surfaces were recorded and saved. The sign above could be seen on the picture. The measuring tool in DIAGNOcam system was used to measure the depth of the caries from the sign (as starting point) to the deepest point of caries in the pictures and its length was recorded for a. The line a was lengthened to the contralateral edge of occlusal surface in the photo and the length was recorded for b. A line from the marked point on the occlusal surface edge of the extracted teeth was draw parallel to the line b on the corresponding photo and its length was recorded for c. The depth of the cavities on the projected images was recorded for d, and calculated d/a=c/b (digital optical fiber measured decay depth/caries damage depth of the image = actual tooth width/tooth width of the image), and d=c/b×a inferred. At last, the teeth were taken out from the standard model dentition. The decay of the tooth was removed completely. The actual depth of the cavity was recorded for D. The difference between d and D was recorded for Δd. The software of SPSS 20.0 was used to test the consistency of the results, and the MedCalc 14.8.1.0 software was used for Bland-Altman analysis. Results: The intraclass correlation coefficient (ICC) between d and D was 0.951 (ICC>75%), P=0.263. There was a function relationship y=0.23+0.91x between d(x) and D(y). BlandAltman analysis method showed that the mean of Δd (Δdmean) was 0.05 mm, the standard deviation of Δd (ΔdSD)=0.308, and the 95% confidence interval was (-0.55 to 0.65). The amplitude of difference was clinically acceptable. So the consistency of the two measurement modes was high. Conclusion: There was no significant difference between the depth of caries lesions checked with DIAGNOcam system and the depth of the actual cavity, and the consistency was very good. The vitro study suggests that the DIAGNOcam system may be used to assess the depth of caries cavity as a useful tool in diagnosis and treatment.

Objective： To compare the technician fabrication time and clinical working time of custom trays fabricated using two different methods, the three-dimensional printing custom trays and the conventional custom trays, and to prove the feasibility of the computer-aided design/computer-aided manufacturing (CAD/CAM) custom trays in clinical use from the perspective of clinical time cost. Methods: Twenty edentulous patients were recruited into this study, which was prospective, single blind, rando-mized self-control clinical trials. Two custom trays were fabricated for each participant. One of the custom trays was fabricated using functional suitable denture (FSD) system through CAD/CAM process, and the other was manually fabricated using conventional methods. Then the final impressions were taken using both the custom trays, followed by utilizing the final impression to fabricate complete dentures respectively. The technician production time of the custom trays and the clinical working time of taking the final impression was recorded. Results: The average time spent on fabricating the three-dimensional printing custom trays using FSD system and fabricating the conventional custom trays manually were (28.6±2.9) min and (31.1±5.7) min, respectively. The average time spent on making the final impression with the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually were (23.4±11.5) min and (25.4±13.0) min, respectively. There was significant diffe-rence in the technician fabrication time and the clinical working time between the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually (P<0.05). Conclusion: The average time spent on fabricating three-dimensional printing custom trays using FSD system and making the final impression with the trays are less than those of the conventional custom trays fabricated manually, which reveals that the FSD three-dimensional printing custom trays is less time-consuming both in the clinical and laboratory process than the conventional custom trays. In addition, when we manufacture custom trays by three-dimensional printing method, there is no need to pour preliminary cast after taking the primary impression, therefore, it can save the impression material and model material. As to completing denture restoration, manufacturing custom trays using FSD system is worth being popularized.

Objective： To compare the fracture resistance of roots of mandibular premolar with diffe-rent apical preparation diameters. Methods: Sixty single-rooted single canal permanent mandibular premolar teeth extracted newly for orthodontic reason without immatureness, fracture or cracks were selected, with a curvature less than 10°, and internal length: short diameter of less than 2 at a level 5 mm from the apex. All the teeth were decoronated, leaving roots 13 mm in length. The initial apical file size for the teeth was ≤15#. The roots were assigned to 6 groups based on weights with random block design. Group A:  blank control group, no instrumentation was performed. Groups B-F: the master apical file (MAF) was 40#, 45#, 50#, 55# and 60#, respectively. In the five experimental groups the roots were instrumented using hand files with stepback technique at 1 mm increments, resulting in a taper of 0.05. The irrigant used was distilled water. After mounted in acrylic resin, all the teeth were subject to vertical loading using an Instron testing machine until fractured. The occurrence of fractures was detected when the applied load suddenly decreased. The fracture load values and fracture modes were recorded. One-way ANOVA and post-hoc Tukey test were used to determine the difference of fracture load values between the groups (P＜0.05). Chi-square tests were used to compare the modes of root fracture. Results: Five experimental groups exhibited lower fracture load values than that of control group ［(1 444±155) N］. The mean fracture load values for roots instrumented to an apical diameter of 50# ［(1 027±128) N］, 55# ［(994±150) N］ and 60# ［(983±166) N］ were significantly lower than that of control group and 40# group ［(1 339±131) N］ and 45# ［(1 287±144) N］ (P<0.05). Buccal-lingual fracture, mesio-distal fracture and compound fracture occurred 55%, 13% and 32%, respectively. No difference of fracture mode was detected in the six groups. Conclusion: The fracture resistance reduced significantly when the roots were instrumented to an apical diameter of 50# or larger.

Objective： To estimate the bond strength between different resin composite interfaces, and to evaluate the effect of saliva contamination and management with the contamination on the bond strength. Methods: Two commercial resin composites containing different types of fillers (AP-X: barium-glass; P60: quartz) were tested in this study. The basic composite blocks were made of AP-X. After wet-ground flatted, the experimental groups were divided into three groups according to the surface treatment: （1）Direct bonding group:  the bonding surface was rinsed with distilled water for 20 s, then dried with oil-free air for 20 s; （2）Saliva contamination group: the bonding surface was bathed in saliva for 30 min, then distilled water was rinsed for 20 s and dried with oilfree air for 20 s; （3）Saliva contamination and 75% ethanol wiping group: bonding surface bathed in saliva for 30 min, then wipe the surface with 75% ethanol, distilled water rinse for 20 s and dry with oil-free air for 20 s; The control group was made of the basic composite bulks of AP-X directly bonding with composite P60. Cut each resin block into 1 mm×1 mm×14 mm sticks, observing the micro-structures and detecting the micro-tensile strength of the resin composite interfaces. The bonding strength was measured using micro-tensile tester, then calculated and statistically analyzed by one-way ANOVA. Results: Scanning electronic microscope observation revealed that the control group as well as the direct bonding subgroups, two dif-ferent resin tags were in good contact with each other. The saliva contamination subgroups had lots of gaps or craters, indicating saliva might have been trapped in the composite buildup and wiping the surface with 75% ethanol had no effect. The micro-tensile bond strength of the control group was (84.07±1.57) MPa and significantly higher than all the other 3 experimental subgroups（P＜0.001）. In experimental groups, the micro-tensile strength of 3 subgroups was (76.08±2.42) MPa, (70.98±2.33) MPa and (71.08±2.33) MPa, respectively. The saliva contamination subgroup was significant lower than the direct bonding subgroup（P＜0.001）, but no statistical significance with the ethanol wiping subgroup（P=0.893）. Conclusion: The bond strength of inner polymerization of resin-resin was greater, but decreased after resin composites interfacial bonding. Saliva contamination reduced the tensile bond strength between resin composites surface, wiping the surface with 75% ethanol had no effect.

Objective： To determine the effects of curing mode of one-step and two-step universal adhesives on the micro-tensile bond strength (μTBS) of different dual-cure resin cements to dentin. Me-thods: One-step universal adhesive Single Bond Universal (SBU), and two-step universal adhesive OptiBond Versa (VSA) were chosen as the subjects, one-step self-etching adhesive OptiBond All in One (AIO) and two-step self-etching adhesive Clearfil SE Bond (SEB) were control groups, and two dual-cure resin cements RelyX Ultimate (RLX) and Nexus 3 Universal (NX3) were used in this study. In this study, 80 extracted human molars were selected and the dentin surface was exposed using diamond saw. The teeth were divided into 16 groups according to the adhesives (AIO, SBU, SEB, VSA), cure modes of adhesives (light cure, non-light cure) and resin cements (RLX, NX3). The adhesives were applied on the dentin surface following the instruction and whether light cured or not, then the resin cements were applied on the adhesives with 1 mm thickness and light cured (650 mW/cm2) for 20 s. A resin was built up (5 mm) on the cements and light cured layer by layer. After water storage for 24 h, the specimens were cut into resincement-dentin strips with a cross sectional area of 1 mm×1 mm  and the μTBS was measured. Results: Regarding one-step universal adhesive (SBU) light cured, the μTBS with RLX ［(35.45±7.04) MPa］ or NX3 ［(26.84±10.39) MPa］ were higher than SBU non-light cured with RLX ［(17.93±8.93) MPa)］ or NX3 ［(10.07±5.89) MPa, P<0.001］. Compared with AIO, light-cured SBU combined with RLX presented higher μTBS than AIO group ［(35.45±7.04) MPa vs. (24.86±8.42) MPa, P<0.05］. When SBU was not lighted, the μTBS was lower than AIO ［(17.93±8.93) MPa vs. (22.28±7.57) MPa, P<0.05］. For two-step universal adhesive (VSA) and control adhesive (SEB), curing mode did not affect the μTBS when used with either RLX or NX3 (25.98-32.24 MPa, P>0.05). Conclusion: Curing mode of one-step universal adhesive may affect the μTBS between dual-cure resin cements and dentin, while for two-step universal adhesive, the curing mode and the type of resin cements did not influence the μTBS.

Objective： To evaluate the influence of sodium hypochlorite (NaOCl) solution used during root canal therapy on dentin bond strength. Methods: In the study, 15 freshly extracted human third molars with complete dental crowns, caries and filling-free were selected. The occlusal enamel was removed perpendicular to the long axis of the tooth to expose middle flat surfaces of sound dentin. The occlusal dentin surfaces were then polished using 600-grit silicon papers for 1 min and rinsed with deio-nized water for 1 min. The teeth were randomly divided into three groups according to the treatment received: group A (negative control group), the samples were immersed in deionized water for 20 min; group B, the dentin surfaces were immersed in 2.50% NaOCl solution for 20 min, with the solution being renewed every 5 min; group C, the dentin surfaces were immersed in 5.25% NaOCl solution for 20 min, with the solution being renewed every 5 min. All the treated dentin surfaces were bonded using a self-etching adhesive system (SE bond) with a 5 mm in height resin composite (AP-X). After storage in deionized water at 37 ℃ for 24 h, the adhesive samples were sectioned longitudinally to produce 1.0 mm×1.0 mm stick specimens(n=45) for micro-tensile bond strength testing (MPa). Failure modes (adhesive failure, cohesive failure or mixed failure) at the dentin-resin interface were observed using a stereomicroscope. The micro-tensile bond strength data among the three groups were analyzed by a one-way ANOVA, then the Post-hoc test（LSD）was employed for pairwise comparison. The distribution of failure modes among the groups were analyzed by chi square test. Results:  Significant decreased bond strength values were found for the 2.50% NaOCl-treated group (26.04±5.74) MPa and 5.25% NaOCl-treated group (24.46±3.77) MPa when compared with the strength of negative control group (48.71±7.77) MPa，P=0.000. Compared with the negative control group, themicro-tensile bond strength of the 2.50% NaOCl-treated group and 5.25% NaOCl-treated grouphad dropped by 46.5% and 50.2%. However, there was no significant difference of bond strength between the 2 NaOCl-treated groups （P=0.214）. The distribution of failure modes showed significant difference in all the three groups （2=56.324, P=0.000）. The mixed failure (68.9%) was the most mode of fracture in the negative control group, followed by adhesive failure(24.4%), and the cohesive failure was least（6.7%）. The proportion of adhesive failure mode was higher in NaOCl-treated groups than in negative control group  (P=0.000)． There was no significant difference of the distribution of failure modes between the 2.50% NaOCl-treated group and 5.25% NaOCl-treated group（P=0.197）, and there was no cohesive failure mode detected in the two groups. Conclusion： The micro-tensile bond strength of dentin to composite resin was lower after exposure to NaOCl solution.

Objective： To investigate the effect of thermal conductivity on the apical sealing ability of different dental gutta-percha cones during the warm vertical condensation obturation. Methods: Four kinds of dental gutta-percha cones were used in this study: Bio-GP points (BP, B&L, Korea), large-tapered guttapercha (DP, DENTSPLY, America), PROTAPER Universal gutta-percha points (DPP, DENTSPLY, America) and mtwo gutta-percha points (VP, VDW, Germany). Volume differences me-thod was used to determine the main components and the thermal conductivity determinator was used to measure the thermal conductivity of these dental gutta-percha cones. Furthermore, 20 cones randomly selected from each kind of dental gutta-percha cones. And 10 cones of each dental gutta-percha cones, which were cut out the part of 4 mm in length from the apical end, were heated (200 ℃) from the upper end without compression, and the temperature of the gutta perchacones surface was monitored in time by the infrared thermal imager during the whole heating process. In addition, the rest of the 10 cones of each dental gutta-percha cones were used to obturate the root canal in the transparent root canal resin model using warm vertical condensation technique. The cross-sectional surface was observed by stereomicroscope (× 40) at 1 mm and 3 mm from the working length and the gutta-percha obturation area proportion was measured and analyzed. The data were analyzed by one-way ANOVA．Results： The proportion of inorganic fillers (80.90%±1.14 %) (P<0.05) and the thermal conductivity (2.247±0.002) of DP was significantly higher than BP (79.28%±3.88%, 1.179±0.003), DPP (68-46%±5.09%, 0.604±0.001), VP (78.86%±1.87%, 1.150±0.001) (P<0.05). During the thermal obturation without compression at the setting temperature (200 ℃), DP could achieve 65 ℃ beyond 1 mm from the heating point, and BP, DPP and VP only reached 65 ℃ within 1 mm. After warm vertical condensation obturation, all the groups showed increased gutta-percha obturation area proportion. At the position of WL-3, DP (96.89%±0.03%) showed significantly higher proportion of gutta-percha obturation area than BP (95.47%±0.06%), DPP (95.21%±0.03%) and VP (95.15%±0.03%) (P<0.05). Conclusion: DP contains more inorganic fillers, possesses higher thermal conductivity, and leads a better apical sealing ability than BP，DPP and VP at the position of WL-3 during warm vertical condensation obturation.

Objective： To investigate the long-term efficacy of oral appliance treating of obstructive sleep apnea and hypopnea syndrome (OSAHS) in different periods of treatment. Methods: A total of 55 patients were included in the study. Patients were all diagnosed with OSAHS by overnight polysomnography and all received oral appliance (OA) as the therapy. The OA positioned the mandible at 60%－70% of the maximal mandible advancement position and created a 4－5 mm incisor separation. The patients were instructed to wear the appliance during sleep, 6-8 hours per day, for 5－7 days per week. They were divided into four groups by the period of treatment, including less than 1 year group; 1－2 years group; 2－6 years group and 6－9 years group. The polysomnographic study was used to investigate the efficacy of the four groups. The outcome measures included the score on the apnea-hypopnea index (AHI), the longest apnea time and the lowest oxygen saturation (LSaO2) levels during an overnight sleep. Results: The AHI decreased significantly in all the four groups. The less than 1 year group decreased from 24.50 (14.65， 54.05) to 7.40 (2.12，10.00) events/h (P<0.001); The 1－2 years group decreased from 19.50 (12.15， 39.23) to 1.80 (0.70， 6.58) events/h (P=0.001); The 2－6 years group decreased from 25.00 (11.41， 42.60) to 4.50 (1.35， 7.90) events/h (P=0.001); The 6－9 years group decreased from 26-2 (16.95， 47.45) to 4.00 (1.90， 26-70) events/h (P=0.043). The longest apnea decreased significantly in less than 1 year group, 1－2 years group and 2－6 years group. The longest apnea decreased from 57.00 (37.70, 61.50) to 25.00 (15.90, 33.50) seconds (P<0.001) in the less than 1 year group, from 41.00 (25.50, 62.26) to 13.10 (0.00, 22.10) seconds (P=0.001) in the 1－2 year group and from 42.50 (30.35, 58.15) to 15.60 (0.00, 28.10) seconds (P=0.003) in the 2－6 year group. The LSaO2 levels increased significantly in the less than 1 year group and 2－6 years group. The LSaO2 levels rose significantly in the less than 1 year group, from 74.18%±7.96% to 84.06%±7.67% (P=0.001), and in the 2－6 years group, from 76.71%±10.98% to 84.06%±4.64% (P=0.006), The LSaO2 levels did not increase significantly in the 1－2 years and 6－9 years groups. Kruskal-Wallis test showed that there were no statistically significant differences in the AHI, longest apnea time and LSaO2 in 4 the groups. Conclusion: The oral appliance is an effective therapy for patients with OSAHS in the long-term treatment. However, it’s recommended to make appointments with patients as a follow-up supervision whether there is any efficacy decrease. And the oral appliance should be replaced if necessary.

Objective： To assess type C behavior in patients with oral lichen planus (OLP) in order to provide basis for clinical prevention, treatment and psychological intervention of OLP. Methods: Type C behavior scale was used on 85 OLP patients and 85 control patients, who were in accordance with the inclusion criteria, in order to investigate their type C behavior. The scale included 9 items: anxiety, depression, anger, anger toward inside (anger-in), anger toward outside (anger-out), reasoning, domination, optimism, and social support. Scores of the 9 items between OLP patients and control group were calculated under the instruction of the scale and were statistically analyzed, and OLP group was further stratified statistically by sex, reticulate-erosive-ulcerative (REU) pathological type and course of diseases, and the scores of each group were analyzed and compared. Results: Among the 85 OLP patients, there were more females, more non-erosive lesion type, and the most common site for OLP was the buccal mucosa. The scores of the type-C behavior questionnaire for anxiety, depression, anger and optimism were respectively 43.01±7.47, 44.02±7.61, 21.56±5.26, 22.15±4.00 among the OLP patients and were 37.94±8.70, 39.58±7.35, 18.12±5.39, 24.05±3.23 among control group, with significant differences(P<0.05 for all) between the two groups. The female OLP patients had higher anxiety, depression, anger scores (43.21±6.97, 44.29±7.54, 21.64±5.09) and lower reasoning, domination, optimism scores (39.12±5.66, 16.29±3.95, 22.05±4.12) with significant differences (P<0.05 for all) compared with those of the female controls. The scores between male patients and male controls showed no significant difference. The patients with erosive lesions had higher anger score (22.94±5.26) than that of the patients without erosive lesions(20.60±5.03), with a significant difference(P＜0.05). With the development of the disease, the tendency of anxiety and depression of the patients were more obvious, while optimism scores remained declining. The patients suffering more than 3 years of OLP had higher anger-toward-outside scores (17.36±3.35) than the patients suffering less than 3 years of OLP (15.19±3.99), with a significant difference (P＜0.05). Conclusion: OLP patients showed an obvious type C behavior characteristic, especially in anxiety, depression, anger and low optimism. This research provides the C behavior characteristic of OLP for further psychological consultation or intervention during OLP treatment.

Objective： To evaluate the impacts of high glucose on the repair function of kidney stem cells (KSC) conditional medium to the hypoxia-injured renal tubular epithelium cells (RTEC). Me-thods: KSC were isolated from the renal papilla in 4-week-Sprague-Dawley rats. The KSC were pretreated in media with high glucose (30 mmol/L) or with normal glucose (5.6 mmol/L), respectively. The supernatants of the pre-treated KSC were collected as the conditional media. The hypoxia/reoxygenation (H/R) model of rat RTEC was established using the NRK-52E cell line. The effects of KSC conditional media on the H/R RTEC were investigated. Results: (1) The best H/R model of RTEC was established using hypoxia for 4 h and reoxygenation 2 h. (2) After hypoxia, the early and late cell apoptosis rates of the H/R RTEC were increased. The H/R RTEC were co-cultured with KSC conditional media for 12 h and 24 h, respectively. The H/R RTEC were co-cultured with DMEM/F12 as a control group. The cell apoptosis rate of H/R RTEC was lower after co-cultured with KSC conditional media (P<0.01), and the cell apoptosis rate of H/R RTEC in high glucose group was much higher than that in normal glucose group after co-cultured 24 h (P=0.02). (3) After hypoxia, the lactic dehydrogenase (LDH) and malondialdehyde (MDA) levels of the H/R RTEC supernatant were increased, and the superoxide dismutase (SOD) level decreased. The LDH and MDA levels were lower and the SOD level was higher after co-cultured with KSC conditional media for 12 h and 24 h, respectively (P<0.01). The LDH and MDA levels of H/R RTEC supernatant were much higher in the high glucose group than in the normal glucose group (P<0.05), and the SOD level of H/R RTEC supernatant was much lower in the high glucose group than in the normal glucose group (P<0.01). Conclusion: KSC conditional media could repair the H/R injury of RTEC. The effects were mainly by inhibiting cell apoptosis, and reducing oxidative stress; the anti-cell apoptosis ability and the anti-oxidative stress capacity of the conditional medium were reduced after KSC were pre-treated with high glucose.

Objective： To investigate the incidence rate and risk factors of acute kidney injury (AKI) after off-pump coronary artery bypass grafting (CABG)，and to compare the effects of AKI on complications after operation and major adverse cardiovascular and cerebrovascular events (MACCE) after 3 years’ follow-up. Methods: In the study, 299 consecutive patients who underwent scheduled off-pump CABG from January 2010 to March 2012 were included. The patients were divided into AKI group with AKI and control group without AKI after operation. The data during perioperative stage were compared, and multivariable Logistic regression modeling was used to identify the risk factors of AKI. The complications were compared after surgery and the patients were followed up for 3 years to observe the difference of MACCE between the two groups. Results: AKI occurred in 37.1% patients (111/299). The elevated serum creatinine levels（Wald=9.276, P=0.002, 95%CI 1.006-1.028）, chronic obstructive pulmonary disease(COPD) （Wald=3.469,P=0.063,95% CI 0.950-7.630）, decreased left ventricular ejection fraction(LVEF)（Wald=4.414,P=0.036,95% CI 0.965-0.999），and implantation of intra-aortic balloon pump (IABP) before or after operation（Wald=6.745, P=0.009, 95% CI 1.336-7.925）were risk factors of AKI in multivariable logistic regression modeling. More complications occurred in AKI group, such as the duration of mechanic ventilation, the time of ICU and the length of stay post operation, reintubation, pulmonary infection, stroke, hemorrhage of digestive tract, the volume of blood transfusion (plasma and red blood cell) and renal replacement therapy（P＜0.05）. The difference of mortality rate had no statistical significance between the AKI group and the control group, but two patients died in the AKI group. The difference of MACCE between the two groups had no statistical significance after 3 years’ follow-up either. Conclusion: The incidence of AKI was high (37.1%) after off-pump CABG. The elevated serum creatinine levels, COPD, decreased LVEF，and implantation IABP before or after operation were independent risk factors of AKI in multivariable Logistic regression modeling. More complications occurred in AKI group during perioperative period, but the difference of MACCE between the two groups after 3 years’ follow-up had no statistical significance.

Objective： To investigate the effects of early rehabilitation training after total knee arthroplasty surgery by continuous femoral nerve block (CFNB) with or without periarticular local infiltration analgesia (PLIA). Methods: In this randomized, double-blind, controlled study, 100 patients under-going primary unilateral total knee arthroplasty in patients with knee osteoarthritis were enrolled. All the patients received CFNB for postoperative analgesia before combined spinal epidural anesthesia. They were randomly divided into 2 groups (n=50 each): CFNB group, CFNB combined with PLIA group (PLIA group). Group PLIA received periarticular local infiltration analgesia with 20 mL ropivacaine (5 g/L), while the equal volume of normal saline was used instead of ropivacaine in group CFNB. Postoperative pain during rest and passive exercises including front and rear portions of knees, the time of ability to perform an active straight leg raise, the time of ability to reach 90° knee flexion, and preoperative and postoperative hospital for special surgery knee score (HSS) were evaluated. Results: Compared with group CFNB, the visual analogue scores (VAS) of front of knees at rest time in group PLIA had no significant difference (P>0.05); there were significant differences at 4, 8, 12, 24 h postoperation in portions of knees at rest time (P<0.05); the VAS had significant differences at 24 h in passive exercises of knees (P<0.05); the VAS had significant differences at 12, 24 h in portions of knees at passive exercises of the knees (P<0.05); the time of ability to perform an active straight leg raise had significant differences in the two groups (P<0.05). Conclusion: Compared with CFNB postoperative analgesia alone, CFNB with PLIA could relieve rest pain and pain during passive movement after total knee arthroplasty. CFNB with PLIA could shorten the time to perform an active straight leg raise and the time of ability to reach 90° knee flexion. And so some patients could improve postoperative rehabilitation training.

Objective： To compare the pain control efficiency of continuous adductor canal block (ACB) and femoral nerve block (FNB) in total knee arthroplasty. Methods: From April to September 2016, patients with severe knee osteoarthritis undergoing primary unilateral total knee arthroplasty (TKA) were prospectively observed, and all the patients were randomized received ultrasound-guided continuous ACB or FNB after surgery. Numeric pain rating scales（NPRS）pain scores in rest and activity 2, 6, 12, 24 and 48 h after surgery were collected, and the preoperative and postoperative quadriceps strength at 24 and 48 h were analyzed. Opioids consumption and anesthesia related adverse effects were also recorded. Results: In the study, 40 patients were enrolled, with 20 patients in each group, male ∶female=7 ∶33, the age: (63.8±10.1) years , and the body mass index (BMI): (28.5±3.5) kg/m2.The general conditions were comparable between the two groups. Though the rest pain 2 h after surgery ［ACB=0.0(0,6), FNB=3.0(0,5), P=0.004］ and activity pain 12 h post operation ［ACB=3.0(3,0), FNB=5.5(0,10), P=0.004］ were lower in ACB group compared with FNB group, there was no statistical difference in the other pain checking points between the two groups. The quadriceps strength 24 h and 48 h after surgery were(85.3±27.6) N and (80.0±30.1) N in ACB group, (69.0±29.4) N and (64.4±32.0) N in FNB group, both of them were declined by time. The exact data were higher in ACB group, however, there was no statistical difference between the two group by repeated measurements variance analysis（F=2.703, P=0.108）.Four patients in ACB group and five in FNB acquired additional use of dolantin once (100 mg/per time) within 24 h. And among them, three patients acquired once dolantin in ACB, two in FNB, from 24 to 48 h postoperation. There were five patients who suffered nausea postoperation in ACB group, and one who reported xerostomia. Four patients in FNB had nausea with vomiting, and three experienced xerostomia. Deep vein thrombosis appeared in 2 patients in FNB group, but no one in ACB group. Conclusion: Continuous ACB is not superior in pain control after TKA compared with FNB, and the quadriceps strength could be reserved more by this method, which performed early benefits in fast rehabilitation.

Objective：To evaluate the feasibility and success rate of in-plane ultrasound-guided paravertebral block using laterally intercostal approach. Methods: In the study, 27 patients undergoing elective thoracic surgery were selected to do paravertebral block preoperatively. The fifth intercostal space was scanned by ultrasound probe which was placed along the long axis of the rib and 8 cm lateral to the midline of the spine. The needle was advanced in increments aiming at the space between the internal and innermost intercostal muscles. Once the space between the muscles was achieved, 20 mL of 0.5% (mass fraction) ropivacaine was injected and a catheter was inserted. Whether the tip of catheter was in right place was evaluated by ultrasound image. The block dermatomes of cold sensation were recorded 10, 20 and 30 min after the bolus drug was given. Then 0.2% ropivacaine was infused with 6 mL/h via the catheter by an analgesia pump postoperatively. The block dermatomes of cold sensation and pain score were recorded 1, 6, 24 and 48 h postoperatively. Results: The first attempt success rate of catheteration was 81.48% (22/27); the tips of catheter were proved in right places after the second or third attempt in 5 patients. The median numbers of the block dermatomes 10, 20 and 30 min after the bolus drug was given were 2, 3, 4; the median numbers of block dermatomes were 5, 5, 5, 4, and of pain score were 1, 1, 2, 2 at 1, 6, 24, 48 h postoperatively; no case of bilateral block, pneumothorax or vessel puncture occurred. Conclusion: Thoracic paravertebral block using laterally intercostal approach is feasible, which has high success rate of block and low rate of complications.

Objective： To evaluate the safety and effectiveness of neglecting superficial femoral artery (SFA) recanalization for chronic lower extremity arteriosclerosis obliterans (ASO). Methods: Thirty-six cases treated for severe stenosis or occlusion of superficial femoral artery resulted from ASO were randomly divided into 2 groups. Twenty of them were treated by endovascular reconstruction of superficial femoral artery and the other 16 cases were not treated with their superficial femoral artery, but were only treated with the accompanied iliac and/or profunda femoral artery lesion. Results: There was no significant difference between the two groups on mean age, gender, ABI before treatment, accompanied diseases, Rutherford classification and trans-atlantic inter-society consensus (TASC) classification （P>0.05）.One week after operation, the reconstruction group had better marked effect and total effective rate ［75.0% vs.12.5%（P<0.001）； 90.0% vs. 37.5%（P=0.001）］ and lower no effective rate ［10.0% vs. 62.5%（P=0.001）］， There was no significant difference between the two groups on effective rate ［15.0% vs. 25.0%（P=0.675）］. The deteriorate cases in both groups were zero, and there was no morbidity of complications and death in both groups during the perioperative period. In the 3-month follow up, the reconstruction group had a better marked effect rate ［65.0% vs.25.0%（P=0.017）］；There was no significant difference between the two groups on the effective rate, no effective rate and total effective rate ［20.0% vs.43.8%（P=0.124）； 15.0% vs.31.3%（P=0.422）； 85.0% vs.68.8%（P=0.422）］. The deteriorate cases and morbidity of complications and death in both groups during the perioperative period were still zero. In the 6-and 12-month follow ups, there were no significant differences between the two groups on marked effect and total effective rate ［60.0% vs.37.5%（P=0.180）， 80.0% vs.87.5%（P=0.672）； 60.0% vs.43.8%（P=0.332）, 85.0% vs.87.5%（P=1.000）］. The deteriorate case was zero in both groups, and there was no morbidity of complications and death in both groups. The limb salvage rate in both groups was 100% during the whole follow up period. The reconstruction group had a higher cost［（53 367.4±24 518.3） yuan vs.（30 397.5±15 354.4） yuan（P=0.011）］. There were 8 cases of SFA restenosis/ reocclusion during the follow up，three of which accepted another endovascular treatment, and the reoperation rate was 15.0%. while in the nonreconstruction group, there was no case that needed another endovascular therapy, and the reoperation rate was zero. Conclusion: Only dealing with accompanied iliac and profunda artery lesion and neglecting superficial femoral artery reconstruction is a safe, effective and inexpensive therapy for chronic lower extremity arteriosclerosis obliterans, and should be the preferred alternative for some patients.

Objective： To investigate the significance of filtration fraction (FF) and renal artery sten-ting in the treatment of atherosclerotic renal artery stenosis. Methods: In the study, 42 cases of renal artery stenosis were treated with 52 renal artery stent implantation. Percutaneous transluminal renal angioplasty and stent (PTRAS) of the patients’ health side kidney, ipsilateral kidney (renal) glomerular filtration rate (GFR), renal effective renal plasma flow effective renal plasma flow (ERPF), kidney filtration fraction changes of preoperative and postoperative serum creatinine (SCR) and the changes in the patients with blood pressure (SBP) and the changes after taking antihypertensive drugs were observed and analyzed. Results:The 52 cases of renal artery stent implantation were all successful. Preoperative ipsilateral GFR was significantly lower than that of normal side (t=－3.989, P=0.000); preoperative ipsilateral ERPF was significantly lower than the contralateral side (t=－4.926, P=0.000). On both sides, the overall FF values were equal (t=1.273, P=0.207). Postoperative ipsilateral renal GFR was increased, but there was no statistical difference (t=－1.411, P=0.164). Postoperative ipsilateral renal ERPF was increased significantly (t=－4.954, P=0.000), and FF lower ( closer to the normal value (t=3.274, P=0.002). Postoperative side GFR was significantly reduced (t=2.569, P=0.000), the contralateral ERPF was significantly reduced (t=3.889, P=0.001), and FF had no significant change (t=－0.758, P=0.454). Postoperative side GFR was lower than that of the contrala-teral (t=－3.283, P=0.002) and postoperative side ERPF was still lower than that of the contralateral (t=－3.351, P=0.001), but on both sides, the FF values were equal (t=－0.361, P=0.719). Preoperative FF was relatively normal in the patients with kidney, and the postoperative FF value change was small (t=0.799, P=0.430); preoperative FF was significantly higher in the patients with kidney, and the postoperative FF value was lower than the preoperative (normal value, t=5.299, P=0.000). Postoperative overall serum creatinine was significantly decreased (t=2.505, P=0.016); but for the patients with unilateral renal artery stenosis, the changes in serum creatinine had no statistical difference (t=1.228, P=0.299); and for the patients with bilateral renal artery stenosis and serum creatinine compared with the preoperative, the changes were decreased significantly (t=2.518, P=0.030); postoperative blood pressure (SBP) was significantly decreased compared with that before operation (t=8.945, P=0.000); antihypertensive drugs taken were decreased significantly compared with the preoperative (t=5.280, P=0.000). Conclusion: For the patients with renal artery stenosis, FF is a useful index to understand the pathophysiological process of renal ischemia. Whether preoperative FF is significantly increased or FF is relatively normal, should be regarded as the indications of renal artery stent implantation.

目的：探讨颅底手术中出现三叉-心反射（trigeminocardiac reflex, TCR）的形成机制、临床特征及相关预后。方法： 回顾性分析2009年1月至2015年10月北京大学第一医院神经外科291例颅底手术患者，通过复习相关的手术资料及麻醉记录，找出术中出现TCR的病例（在刺激或操作三叉神经相关区域时，出现与麻醉因素无关的平均动脉压突然下降和心率突然减慢并超过基线值的20%）， 分析其手术方式、临床特征、影响因素及相应预后。结果： 291例颅底手术患者中，9例患者术中共出现TCR 19 次，包括神经鞘瘤4例（听神经瘤3例，三叉神经鞘瘤1例）、脑膜瘤1例、表皮样囊肿1例、海绵窦海绵状血管瘤1例、垂体瘤1例、三叉神经痛1例。TCR诱发方式均与三叉神经主干或其分支受操作、牵拉有关，操作前基线心率为62~119 /min，平均（79.4±14.6） /min，TCR发生时，心率为22~60 /min，平均（44.2±9.6） /min，心率下降比例为29.0%~66.4%，平均下降比例为44.3%。基线平均动脉压为75~103 mmHg，平均（87.5±7.8） mmHg，TCR发生时，平均动脉压为45~67 mmHg，平均为（54.9±6.3） mmHg，血压下降比例为23.4%~47.2%，平均下降比例为37.3%。TCR出现后，停止刺激或操作心率血压自行恢复者8例次，应用阿托品8例次，剂量0.5~1.0 mg，平均0.69 mg,应用盐酸麻黄碱1例次,应用肾上腺素1例次，应用多巴胺1例次，患者血压及心率均很快恢复至基线水平，重复刺激可再次诱发。术后24 h无TCR相关心血管并发症及神经功能障碍。结论： TCR是在颅底手术中由于对三叉神经或其分支操作刺激时出现的一种以心率变慢、血压降低为表现的神经反射，虽然其预后良好，但仍需正确判断、密切观察，必要时需给予处理。

Objective： To evaluate bone formation in human extraction sockets with absorbed surroun-ding walls augmented with Bio-Oss-and Bio-Gide-after a 6-month healing period by histologic and histomorphometric analyses. Methods: Six fresh molar tooth extraction sockets in 6 patients who required periodontally compromised moral tooth extraction were included in this study. The six fresh extraction sockets were grafted with Bio-Oss-particle covered with Bio-Gide^R. The 2.8 mm×6.0 mm cylindric bone specimens were taken from the graft sites with aid of stent 6 months after the surgery. Histologic and histomorphometric analyses were performed. Results: The histological results showed Bio-Oss-particles were easily distinguished from the newly formed bone, small amounts of new bone were formed among the Bio-Oss-particles, large amounts of connective tissue were found. Intimate contact between the newly formed bone and the small part of Bio-Oss-particles was present. All the biopsy cylinders measurement demonstrated a high inter-individual variability in the percentage of the bone, connective tissues and Bio-Oss-particles. The new bone occupied 11.54% (0-28.40%) of the total area; the connective tissues were 53.42% (34.08%-74.59%) and the Bio-Oss-particles were 35.04% (13.92%-50.87%). The percentage of the particles, which were in contact with bone tissues, amounted to 20.13% (0-48.50%). Conclusion: Sites grafted with Bio-Oss-particles covered with Bio-Gide-were comprised of connective tissues and small amounts of newly formed bone surrounding the graft particles.

Objective： To introduce a technique of second order wave-shaped arch wire to orthodontically treat dental occlusal plane canting (DOPC) with left-right interactive anchorage, and to test its cli-nical efficacy. Methods: Among the permanent dentition malocclusion patients who showed no obvious facial asymmetry, we screened for patients who showed anterior occlusal plane canting (AOPC) after routine orthodontic examination, treatment planning, MBT fixed appliance installation and serial arch wires alignment. Each patient had been clinically appraised in frontal view by 2 orthodontists and the patient him/herself; if all 3 agreed that the AOPC was obvious, the patient was included. By this means, we included 37 patients, including 10 males and 27 females; the average age was (21.9±5.2) years. To correct AOPC, opposite direction equal curvature second order rocking-chair curve was bent on each side of 0.46 mm×0.56 mm stainless steel edgewise wire. With reference to normal occlusal plane, a curve toward the occlusal surface was made to extrude undererupted teeth on one side while a curve toward the gingiva was made to intrude over-erupted teeth on the other side, so that the arch wire was made into a wave shape in vertical dimension. Before and after application of wave-shaped arch wire, frontal facial photographs were taken when the patient’s mouth was open slightly with lips retracted to show anterior occlusal plane (AOP) clearly. An AOP was constructed by connecting the center of the slot in the medial edge of canine bracket on each side in the photograph. The angles between the bipupillary plane(BPP) and the constructed AOP were measured in ImageJ1-48v software and the angle differences before and after treatment were compared with paired Wilcoxon test in SPSS 10.0 software. Results: The wave-shaped arch could correct AOPC effectively in 3 to 10 months time with an average of 5.5±1.7 months; the angles between AOP and BBP before treatment ranged from 2.90° to 6.12° with a median of 4.01°; after treatment the angles were from -0.17° to 2.57° with a median of 1.87°, the decrease of the angles between AOP and BBP after treatment ranged from 1.08° to 4.15° with a median of 2.21°. Paired Wilcoxon test P was 0.000. Conclusion: The wave-shaped arch can be used independently or in combination with other treatment methods, which can take advantage of left and right interactive anchorage to correct AOPC effectively, so it has certain application value in clinical practice.

Tooth eruption is defined as the movement of a tooth from its site of development within the alveolar process to its functional position in the oral cavity. The process of tooth eruption can be divided into different phases: pre-eruptive bone stage, alveolar bone stage, mucosal stage, preocclusal stage, occlusal stage and maturation stage. Any disturbance in these phases can lead to eruptive anomalies. The incidence of unerupted teeth is usually higher among permanent teeth than among deciduous ones. Of the primary teeth reported as unerupted, second deciduous molars are the teeth most frequently involved, followed by primary central incisors. At present almost no coverage is seen about the impaction of the first deciduous molar. In this case, a 4-year-old boy who presented with an impacted left maxillary first deci-duous molar came to the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. This tooth, located higher to the left maxillary first premolar, was well near to the maxillary sinus. The family and medical histories were noncontributory and his physical findings were within normal limits. The mother was reported as having experienced no illness or other complications and taken no medications during pregnancy. His clinical extraoral examination was noncontributory. His clinical intra-oral examination revealed that the maxillary left first primary molar was not present. No enlargement of the area was apparent visually or on palpation. The remaining primary dentition was well aligned and in good condition. His oral hygiene was good, although there were incipient occlusal carious lesions in the mandibular second primary molars. There was no history or evidence of dental trauma. A diagnosis of a left maxillary first deciduous molar was made on the basis of the clinical and radiographic evidence. Numerous local etiologic factors have been described for impacted teeth. These include anomalous teeth, malposition, fusion with adjacent or supernumerary teeth, odontoma, dentigerous cysts, tumors, underdevelopment of the jaws, keratinized epithelial lining, hereditary conditions, and trauma. In this case, the reason for impaction was not clear. After the comprehensive clinical evaluation, treatment consisted of placement of a space maintainer, the periodic examination was indicated for the follow-up, so that early interventions, such as subsequent surgical intervention and orthodontic traction could be recommended timely to manage orofacial disfigurement and to avoid consequent problems with resultant proper functioning and good periodontal health.