Objective To compare the difference of the osteoclastic factors expression between the regenerated periodontal tissue and the healthy periodontal tissue under orthodontic compressional stress. The periodontal tissue was regenerated with the modified biaphasic calcium phosphate(BCP) as scaffold and bone marrow mesenchymal stem cells(BMSCs) as seed cells. To further investigate the possibility of orthodontic tooth movement after periodontal tissue regeneration. Methods Six male beagle dogs were grouped as 1week group,2week group and 4week group randomly. The first premolars were extracted and periodontal defects were made on the mesial aspect of the second premolar. The BMSCs from the dogs were cultured and seeded onto the modified BCP. In experimental group,the BMSCsmodified BCP complex was implanted into periodontal defects in the right upper and left lower quadrant. After 20 weeks of recovery,orthodontic compressional stress was initiated with 1.47 N force. Selfcontrolled experiment was applied,and the other two quadrants were set as 0week group without orthodontic force and control group without neither surgery nor orthodontic force,alternatively. Then two dogs were sacrificed after 1,2 and 4 weeks,and the expressions of NFATc1 and CathK were detected by RealTime PCR and WesternBlot. Results In experimental group,the expression of NFATc1 and CathK in periodontal tissues increased from 0 week to 2 weeks and decreased till 4 weeks. There were no significant differences in expression of these two osteoclastassociate transcript factors between two groups. Conclusions The expression of osteoclastic factors in regenerated periodontal tissue made no difference from that in the healthy periodontal tissue,which brings about the possibility of orthodontic tooth movement after periodontal tissue regeneration.

Objective Realtime quantitative PCR technique would be used to investigate the distribution and levels of A. Actinomycetemcomitans (Aa) and P. Gingivalis (Pg) in subgingival plaque samples from subjects with aggressive periodontitis (AgP) and chronic periodontitis (CP). Methods Subgingival plaque samples were taken from 32 patients with AP,33 patients with CP and 32 periodontal healthy controls. We constructed recombinant plasmid containing speciesspecific gene fragments and the serial dilution of the plasmid standards,and then the bacteria were quantified by realtime PCR with TaqManMGB probes. Results This method showed accurate specificity and sensitivity,and the prevalence of Aa in AgP group was significantly higher than that in CP group,but no significant differences in the counts of both pathogens were found between periodontitis groups. The prevalence and bacterial counts of Pg were significantly higher than those of Aa within each periodontitis group(P＜0.001). In addition,a significant positive correlation was found between the probing depth and the counts of Aa in AgP group (P＜0.01) as well as that of Pg in CP group (P＜0.001). Conclusions These findings indicate the possible relation between the prevalence of Aa in the subgingival plaque and the diagnosis of periodontitis. Moreover,Aa may not be the predominant periodontopathic bacteria in individuals with AgP in Chinese. There is a great potential in the application of the realtime quantitative PCR in the periodontal research.

Objective To investigate the BMP-2 and TNF alpha(TNF-α) on osteoblast proliferation and differentiation of different function and comparative analysis through the BMP – 2 and TNF alpha were stimulated the generation of osteoblast culture. Methods Wistar rat (1 week old) skull were surgery chipped under sterile conditions and osteoblasts were extracted, primary cell cultures, and passaged, purification, amplification. Using different concentrations of BMP-2 and TNF- α induced rat osteoblasts, Methyl thiazolyl tetrazolium (MTT) assay was used to detect the proliferation of osteoblasts, PP-nitrophenyl phosphate (PNPP) was used to detect the alkaline phosphatase (ALP) activity of osteoblasts.Results In vitro cultured cells by ALP staining and calcification were both positive, confirmed the cultured cells have the typical characteristics of mature osteoblasts. Rat osteoblast proliferation activity and ALP activity increases with BMP - 2 concentration, but decreased with increasing TNF-α, there was significant difference with control group (P < 0.05). Conclusion Transfection of BMP-2 can improve the proliferation and differentiation of osteoblasts. TNF- α has inhibitory effect on the proliferation and differentiation of osteoblasts. BMP -2 and TNF alpha respectively promote and inhibit in vitro culture of osteoblasts through different mechanisms.

Objective To investigate the changes of occlusal relationship during the treatment of the second molar scissors bite with modified fixed inclined biteplate. Methods 24 cases (9males,15females,aged from 12~15 years,with the average age of 13.5 years old) were treated with modified fixed inclined biteplate. Cephalometric analysis was carried out before and after treatment.Results After 3 to 4 months′ treatment,the scissors bite of the second maxillary molars was corrected. The mandible showed forward movement. Occlusal relationship came to class I,and the soft tissue profile has improved greatly. The clinical crown height of mandibular molars grew significantly while the growth of upper molars was unobvious. Conclusions Modified fixed inclined plate is a simple but effective intraoral device in treatment of the second maxillary molar with buccal crossbite. It did not cause the clinical crown height of maxillary molar to grow,and the hard and soft tissue changes are satisfactory. This kind of device especially applies to the treatment of the lowangle patients.

Objective To evaluate the longterm clinical efficacy and adverse reactions of the joint of LBP and TGP in the treatment of recurrent aphthous ulcers (RAU). Methods A total of 160 RAU patients were randomly divided into two groups. 80 patients in the treatment group were treated with TGP and LBP extracting from Ningxia lyeium barbaom,and another 80 patients in the control group were treated with TGP only. The course for two groups was 6 months. Then the efficacy was evaluated according to the “RAU Evaluation trial standards” of Chinese Stomatological Association Professional Committee of mucosal disease.Results The efficiency of LBP combined with TGP group was significantly better than the TGP group,with less adverse reactions. Total intermittent periods of two RAU patients groups were extended,and the total number of ulcer in both groups decreased and there was a significant difference in its intermittent period (P<0.01).There was no significant difference in the changes of the number of ulcers (P>0.05). Conclusions The LBP combined with TGP treatment of RAU had a good longterm efficacy,safety and minor adverse reactions.

Objective To investigate changes of the cytokine levels in the gingival crevicular fluid after applying force on the selfligating brackets and conventional brackets,and analyse the periodontal tissue remodeling.Methods Sixteen maxillary protruding patients who needed removing bilateral maxillary first premolars were selected,selfligating appliance being used on one side of the upper dentition as the experimental group,and using traditional straight wire appliance on the other side as the control group.IL1β and PGE2 levels of the gingival crevicular fluid taken at different time points in canine retraction were detected,and to analyze the relationship of their changes with periodontal tissue inflammatory response.Results After retruding the canines,levels of IL1β and PGE2 of the gingival crevicular fluid all increased and reached their top at 24 h.There were no significant differencesin IL1β and PGE2 levels of the gingival crevicular fluid between the experimental group and control group.Conclusions Selfligating appliance did not differ significantly from traditional appliance in periodontal tissue remodeling in the early phase of the orthodontic tooth movement.

Objective To observe the adhesion and growth of human periodontal ligament stem cells (PDLSCs) seeded on small intestinal submucosa (SIS) in vitro and the osteogenic induction of SIS. Methods PDLSCs were successfully isolated and cultured. The compatibility of the biomaterial was evaluated by MTS assay. The osteogenic differentiation of PDLSCs induced by SIS was measured by using Alizarin red staining,the alkaline phosphatase (ALP) activity and reverse transcriptionpolymerase chain reaction (RTPCR) assay. Results The proliferation of PDLSCs in SIS groups was obviously higher than that in the control groups. The higher levels of ALP activity,the larger mineralizing nods were also detected in the experiment groups. RTPCR demonstrated mRNA expression of bone sialoprotein (BSP) and osteocalcin (OCN) in PDLSCs induced by SIS. Conclusions SIS possesses a good cellular compatibility with PDLSCs. It can induce the osteogenic differentiation of PDLSCs.

Objective〓〖WTBZ〗To study the effects of dental cements on corrosive nature of titanium materials.〖WTHZ〗Methods〓〖WTBZ〗 In this study titanium species were respectively cemented with two kinds of cements (GC and PC) which were routinely used in prosthodontic area.And then these specimens were immerged in artificial saliva for 8 weeks.Electrochemical impedance spectroscopy and polarization curve tests were taken after the immersion.〖WTHZ〗Results〓〖WTBZ〗From the Nyquist plots of electrical impedance spectroscopy (EIS) we saw that the GC group showed the smallest semicircular diameter of capacitance loop.In the broad low and middle frequency range of Bode plots,the impedance of GC group was the lowest.And the largest phase angle value of GC group was also the smallest.Values for the elements obtained from the equivalent circuit showed that the constantphase element (CPE) of GC group was significantly higher than the other two groups（P<0.05）.And the values of resistance of barrier layer (Rb) have increased as follows:GC

Objective To explore the protein expression of Akt,pAkt,in the human dental pulp cells stimulated by LTA and LPS,and to investigate the protection function of IGF1 to the human dental pulp cell.Methods MTT chromatometry was used to determine cell inhibition rate of HPDCs stimulated by different concentrations LTA and LPS,and to determine cell inhibition rate of HPDCs costimulated by IGF1 and LTA or LPS.The protein expression of Akt,pAkt,in HPDCs were then evaluated by western bloting.Results LTA and LPS inhibited HPDCs viability in a dosedependent fashion.IGF1 had a protection function of HPDCs inhibition caused by LTA and LPS.The protein expression of pAkt(Ser473) in HPDCs costimulated by IGF1 and LTA or LPS was higher than other groups.Conclusions IGF1 had a protection function to HPDCs inhibition caused by LTA and LPS,and this function might have a relationship with PI3K/Aktpathway.

Objective To study the shaping ability of Mtwo instruments by perparing the simulated curved root canals.Methods Two groups resin blocks were prepared by Mtwo and ProTaper instruments.We recorded the materials removed and changing of the root canal shape.The images before and after preparation were superimposed and analyzed by software.Results There was no statistical signifcance between Mtwo and ProTaper instruments.Conclusions The Mtwo instruments show a good performance in preparing the simulated curved root canals.

Objective To evaluate the clinical effects of diode laser in the secondarystage implant surgery.Methods The 207 implants of 84 patients whose gum covered the surface of implant were treated with diode laser irradiation under the superficial anesthesia three to six months after implantation.The cover screws were taken.The healing abutments were placed on the implants.The ceramometal crown restoration was performed two weeks later.The outcomes were evaluated one month after restoration.Resuits There was no hemorrhage during operation; the operation time was short; there was no pain or swelling after operation and the cut healed quickly.Among the 207 implants,194 implants(93.72%) were at good stage,9 implants(4.35%) were at general stage,and 4 implants (1.93%) were at poor stage.The implant survival ratio was 98.07%.There were no complications.Conclusions Diode Laser is painless,accurate,comfortable,effective,safe and of small harm in the secondarystage implant surgery.

Objective To observe the clinical effect of the application of orthodonticimplant sequential treatment for longterm first molar defect.Methods Orthodontic methods were adopted,including erecting tipped tooth,lowering overerupted tooth,redistributing space of denture to regain enough space for implant restoration.Results Satisfactory esthetic and functional results were achieved for all the cases.Conclusions These results suggest that orthodonticimplant sequential treatment for restoration of patients with longterm first molar defect is necessary and optimal results can be obtained.

Objective To evaluate the effect of ferrule length on the survival of residual crown and roots restored with prefabricated fiber post and core system. Methods 68 defect teeth of residual crown and roots from 56 patients were collected in this study. After prefabricated fiber post and core restoration,all teeth were prepared with different ferrule lengths (0~1 mm,1~2 mm,more than 2 mm) and restored with ceramic crowns. The success rate of prostheses was observed after 2 to 5 years and the data was analyzed by χ2 test. Results The success rates for roots with the ferrule length among 0~1 mm,1~2 mm and more than 2 mm were 60% (12/20),96.8% (30/31) and 100% (17/17) respectively. There were significant differences between roots with ferrule length of 0 to 1 mm and roots with ferrule length of more than 1 mm(P＜0.05). Conclusions More than 1 mm ferrule length will significantly increase the success rate of pulpless residual roots. 

Objective To evaluate the effect of supportive periodontal therapy on maintaining the longterm effect of periodontal nonsurgical treatment. Methods A retrospective study was carried out on patients who have received periodontal treatment before in stomatology hospital. 16 of the patients received supportive treatment while 14 others didn′t. Clinical periodontal examination included periodontal probing depth (PD) and bleeding on probing positive position (BOP (+)). The above clinical examination indexes at the first visit,the return visit after 6 weeks,and the latest visit were analyzed and compared. Results 6 weeks later,PD and BOP(+) percentage in two groups decreased significantly and there was no statistically significant difference between the two groups. At the latest visit,the PD of supportive therapy group was 2.83 mm and the BOP(+) percentage was 15.49%. There was significant difference compared with the 1st visit.The PD of control group was 3.51 mm and the BOP(+) percentage was 60.42%.There was no statistically significant difference compared with the 1st visit,but there was significant difference when compared with the supportive therapy group. Conclusions Periodontal nonsurgical treatment can effectively control periodontitis but its longterm effect needs to be maintained through supportive periodontal therapy.

Objective To evaluate the effects of combined application of rapid maxillary expansion and fixed appliance on dental arch,basal bone sagittal and vertical. Methods Rapid maxillary expansion and fixed appliances were used in nonextraction treatment on 30 mild to moderate crowding cases of permanent dentition and they are divided into two groups:a hyperdivergent group (mandibular plane angle >32 °; n=20) and a normal vertical dimension group (mandibular plane angle ≥22 ° and ≤ 32 °; n=10). Cephalometric analysis was done at T1 (pretreatment),T2 (rapid maxillary expansion after 3 months) and T3 (after fixed appliance treatment). Results No significant differences in treatment effects were found in vertical dentoskeletal variables examined in two groups. There were significant differences in mandibular plane angle at the 3 time points.Y axis,total facial height,upper anterior facial height increased significantly during T1T2 and T1T3. Conclusions Rapid maxillary expansion will lead to downward rotation of the maxillary and mandibular,but there is no clinical significance due to the small variation of the absolute value. Hyperdivergent is not a contraindication for rapid maxillary expansion therapy.

Objective To evaluate the clinical effects of application of reverse Twinblock in treating mixed dentition of Angle class Ⅲ malocclusion.Methods Reverse Twinblock appliance was applied in the treatment of mixed dentition period of class Ⅲ malocclusion in 11 cases,and cephalomertric analysis was performed before and after treatment.Results The profiles of 11 patients of mixed dentition period of class Ⅲ malocclusion have improved,and their anterior teeth overbite and overjet became normal.Conclusions Reverse Twinblock appliance is effective in the treatment of mixed dentition period of class Ⅲ malocclusion.

Objective 　To explore Cyclin D1 expression in oral squamous cell carcinoma of Chinese people and its clinical significance.Methods 　The CNKI,CMCI,VIP,CBM,Wanfang databases were searched electronically. The literature concerning Cyclin D1 and domestic oral squamous cell carcinoma from 2000 to 2013 were included for Meta analysis. Results 　A total of 12 casecontrol studies were carried out,involving 629 cases of oral squamous cell carcinoma and 227 cases of normal oral mucosa. The metaanalysis results showed that the average positive expression rate of Cyclin D1 in oral squamous cell carcinoma of Chinese people was 69%,and the OR value was 20.51 with 95% confidence interval ［CI］12.50 to 33.66,P<0.000 01 ; Cyclin D1 was correlated with node metastasis (P<0.000 01) and clinical stage T (P=0.01) of oral squamous cell carcinoma lymph. Conclusions Cyclin D1 expression is related to the occurrence of oral squamous cell carcinoma of Chinese people,which can be considered as the auxiliary detection index in treatment of oral squamous cell carcinoma and its prognosis.

Objective To investigate the dentofacial features of normal adults in Harbin area with Jarabak cephalometric analysis to set up a normal value of this analysis method in this area. Methods 56 normal adults who were born and bred in Harbin (including 30 male with average age of 22 and 26 female with average age of 21) were selected for this study. Lateral cephalometric X-rays were taken under natural head position (NHP). Computer aided methods were used for Jarabak cephalometric analysis and statistic analysis．Results The range of normal value of Jarabak analysis in Harbin area was obtained. Conclusions The results of the study show that there are no significant differences between male and female groups in angle measurements,but there are significant gender differences in the linear measurements.