Objective To detect the effect of stem cell factor (SCF) combined with PluronicF127 gel on the directional migration of bone marrow mesenchymal stem cells (BMSCs),then investigate the effect on healing after repair of mandibular defects in rats.Methods ①Transwell chamber was used to observe the migration of BMSCs in SCF gel group and blank control group.Count the number of migrated cells.②Bone defects 3 mm in diameter were established in 30 clean SD rats′ bilateral mandibles,on the right sides of which composite material was injected,while the left sides of which served as control group.6 rats were sacrificed separately in the 1st,2nd,4th,6th,8th weeks after surgery.The mandibles were taken out and the bilateral bone defects were observed by Xray.The specimens were fixed,sliced and dealt with histochemical staining of alkaline phosphatase(ALP) and CD34 separately.The staining was scored.The growth of new vessels was counted.T test was used to analyze and judge the results.Results For bone marrow mesenchymal stem cells cultured in vitro,chemotaxis assay showed that number of migrated cells in SCF gel group was more than that in blank control group（P<0.05）.Composite material in the wound of rats was gradually absorbed 18 weeks after mandibular surgery.Scores of ALP immunohistochemical staining in SCF gel group was higher than that in blank control group after surgery（P<0.05）.Number of new vessels in experimental group was more than that in control group 12 weeks after surgery（P<0.05）,while two groups had no significant difference in number of new vessels during 48 weeks （P>0.05）.Conclusions Composite SCFgel can migrate BMSCs to certain degree.Furthermore,it can promote new vessels′ growth and new bones′ formation and accelerate healing process of orthopaedic injuries in vivo which are larger than selfhealing bone defects.

Objective To investigate the law of TGFβ/Smad signal molecule expression in midpalatal suture remodeling after subjecting to tensional strain loading.Methods 36 Wistar male rats of 5 weeks old were divided into experimental group and control group (including negative controls and blank controls).The expansion appliances were placed into rats in experimental group,with opening loops with an initial force of 0.49 N applied to midpalatal suture.After expansion for periods of 1,4 and 7 days,IHC staining was used to investigate the expression of TGFβ/Smad signal molecules during midpalatal suture expansion at different time points.Results In rat midpalatal suture expansion,expression of TGFβ1,2,3,Smad2,3 and 4 was upregulated,especially in marginal periosteum cells， osteoblasts,secondary cartilage layer，pulp cavity and mesenchymal cells in sutura fiber layer and marginal bone.Expression of Smad7 was kept in a low level.Conclusions Mechanical tensil stress may regulate the expression pattern of TGFβ/Smad in suture cells to stimulate their proliferation,which leads to suture distraction osteogensis.

Objective To study the effects of two different nanoparticles on the mechanical properties of selfdeveloped highstrength glass fiber reinforced lightcured resin composite posts.Methods Configure our own lightcured resin matrix,add nano ZrO2 and nano Al2O3 into resin matrix in the proportion of 1%,3%,4%,5%,make them into FRC posts by pultrusion,and universal mechanical testing machine was used to test flexure modulus,flexure strength and fracture loads of FRC posts.Results Different contents of nano particles affected the mechanical properties of FRC posts.FRC posts made of lightcured resin containing 4% nano ZrO2,nano Al2O3 had the best overall performance:flexure modulus （20.42±0.88）、（19.96±0.69） GPa，flexure strength（464.89±18.84）、（481.17±24.68） MPa，flexure load （146.05±5.92）、（151.23±7.79） N,which had significant difference with FRC posts adding no nanoparticles(P<0.05).Conclusions A small amount of nanoparticles can toughen FRC posts.

Objective To investigate if different RNA extraction methods could affect the total RNA concentration and integrity of samples dissected by LMD system from murine tooth germs.Methods According to the different RNA extraction methods,the samples were divided into three groups:RNA extraction kit group,classic Trizol method group and modified Trizol method group.The tooth germ tissues of the mandibular first molars of CD1 mice at E17 and PN2 stages were dissected by LMD6000 system.Total RNA was extracted from each group in the 3 ways.To ensure the integrity of RNA samples,quality check was adopted with Bioanalyzer 2100 System,Agilent.The 28 S /18 S ratios of ribosome RNA,RNA integrity numbers (RIN) and the peak patterns of the electrophoretograms were integrated as the indices of RNA integrity.The RNA concentration and integrity of all the groups were compared with SPSS statistical analysis software.Results The RNA concentration in modified Trizol method group was the highest,which had significant difference compared with the other two groups.The classic Trizol method group had higher concentration than RNA extraction kit group,however,the difference didn′t have statistical meaning.The comparison of RNA integrity among three groups showed no significant differences taking RIN numbers and 28 S/18 S ratios and electrophoretograms as indicators.Conclusions Our experiment preliminaryly proves that modified Trizol method can extract most total RNA compared with other two groups,while there is no stastically significant difference in RNA integrity among 3 methods.Modified Trizol method will be helpful to get chip experimental samples that meet the inspection standards for high flux experiment.

Objective To investigate the expression of IFNγ and IL10 before and after periimplantitis animal models were built.Methods Select 5 beagle dogs,extract premolars in each dog.3 months after extraction,gingiva perforating pure titanium implants were implanted under general anesthesia.3 months after implantation,ligature wires were used to bind the necks of implants for 3 months,and bone defect more than 40% reached the evaluation standard.Before and after periimplantitis models were built,get the gingival crevicular fluid.Contents of IFNγ、IL10 were evaluated by enzymelinked immunosorbent assay before and after periimplantitis models were built.SPSS was used for statistical analysis.Results The mean value of IFNγ in PICF was 6.64 ng/mL,while that in controll group was 2.22 ng/mL（P=0.01）.The mean value of IL10 in PICF was 5.78 ng/mL,while that in the controll group was 4.78 ng/mL（P=0.54）.Conclusions Level of IFNγ increases significantly in PICF,while IL10 increases with no statistical significence in periimplantitis.

Objective To observe and evaluate clinical efficacy of bone morphogenetic proteininduced active material (osteoinduction active material,OAM) combined with bone autotransplantation to periodontal tissue regeneration and to investigate the impact of different proportions of OMA mixed with autologous bone on periodontal guided tissue regeneration.Methods Thirtynine teeth with periodontal osseous defects were selected and divided into three groups.Thirteen teeth were cured by guided tissue regeneration(GTR) using OAM mixed with autologous bone in 1∶1(group A),thirteen teeth by GTR using OAM mixed with autologous bone in 2∶1(group B) and thirteen teeth by GTR using OAM merely(group C).Clinical indicators like periodontal probing depth(PPD) clinical attachment loss(CAL) and sulcus bleeding index(SBI) were recoreded before operation,and at 12th,24th week after operations.Results The clinical parameters in three groups showed statistically significant changes compared with baseline for all of the evaluated parameters.PPD and CAL significantly reduced at 12th week after operation(P＜0.05) without significant difference at 24th week(P＞0.05) among three groups.No significant differences of PPD and CAL were found between group A and B.SBI reduce showed no significant difference (P＞0.05) among three groups.Periapical films or CBCT before and after operation demonstrated new bone formation in bone defect areas in three groups.Bone density of group A and group B at 12th week increased more significantly compared with group C.Conclusions OAM combined with bone autotransplantation is an ideal method for periodontal tissue regeneration.In this way,periodontal tissue repair occurs earlier compared with OAM merely.No significant correlation is found between the function of periodontal guided tissue regeneration using OAM mixed with autologous bone and proportions of the mixture.

Objective To investigate blone formation,material′s degradability and biological safety using selfdesigned degradable AZ31 magnesium alloy distractor on mandibular distraction osteogenesis (DO).Methods 12 mongrel dogs were used in this study.Unilateral three odontoprisis were moved out 3 months before mandibular osteotomy.Then,unilateral mandibular osteotomy was performed on 12 dogs.By operation,selfmade magnesium alloy and stainless steel distractors were implanted.After 5 days′ latency,the dogs in two groups underwent distraction at the rate of 0.3 mm/8 h for 7 days and entered into consolidation period.12 dogs were respectively sacrificed at the fourth week after consolidation.Vertical height measurements of mandibles,scanning electron microscopy (SEM),histological and liverkidney pathological evaluations were performed,but nothing abnormal was detected.Results The segments in alveolar direction were augmented (6.300±0.018) mm in experimental group and (6.307±0.027) mm in control group.There were no obvious differences (P>0.05).Active osteoblasts,trabeculae and a little mature bone tissue gradually formed in distraction space of two groups.There were obvious cracks on surfaces of the magnesium alloy.There were no abnormalities in the pathological analysis of liver and kidney tissue in experimental group.Conclusions It suggests that four weeks after distraction with AZ31 magnesium alloy distractor,the height of mandibular has been increased and an adequate bone has been created.AZ31 magnesium alloy has a certain degradation speed in mandibles.AZ31 magnesium alloy has not any negative effect on liver and kidney tissues.

Objective To examine the expression of nuclear factorkappa B(NFκB),tumor necrosis factoralpha(TNFα) and interleukin1β（IL1β）in oral lichen planus(OLP) and to investigate the roles of these three cytokines in the development of OLP.Methods Immunohistochemical technique with SP method was used to detect the expression of NFκB、TNFα and IL1β in 35 OLP cases and 10 normal oral mucosa specimens.Furthermore,their correlation and their respective relationship with clinical features of OLP were analyzed.Results NFκB positive staining was mainly found in cytoplasm and nucleu of cells,and it mainly expressed in spinous and basal epithelial keratinocytes and in lamina propria of filtrated lymphocytes.TNFα positive and IL1β positive stainings were mainly detected in cytoplasm and they mainly expressed in the spinous and basal keratinocytes and in filtrated lymphocytes.Expression of NFκB and TNFα、IL1β might be related to clinical classification,but it had not close relationship with lesion sites,genders and ages.Conclusions High expression of NFκB and TNFα,IL1β and the positive correlation of NFκB and the other two in OLP suggest that NFκB signal transduction loop activation has close relationship with overexpression of TNFα and IL1β in the pathogenesy of OLP.

Objective To analyze clinical effect of extraoral appliance in nonextraction treatment of cases of Angle classⅡ1 malocclusion in different maxillary second molar eruption statuses.Methods 36 cases of Angle classⅡ1 malocclusion,who were treated with extraoral appliance in permanent dentition without extraction were chosen,aged 1015 years old with an average age of 12.5 years old.They were divided into four groups according to different maxillary second molar eruption statuses.Pretreatment and posttreatment lateral cephalometrics were analyzed by ANOVA to compare treatment effects.Results Maxilla had a very significant change before and after treatment.The group in which maxillary second molar germs were below maxillary first molar necks had the most indexes which were statistically significant (SNA,ANB,Wits distance,U6Ptv,overjet)， which were obviously better than those in the other three groups.Conclusions Traction with face bows can improve deep overjet in permanent dentition and correct molar relationship.It′s the best choice when the second permanent teeth haven′t erupted,especially when tooth germ is below first molar neck.

Objective To investigate the in vitro culture of osteoblasts of human healthy and periodontitis alveolar bones.Methods Human healthy and inflammatory osteoblasts of alveolar bones were selected,cultured and subcultured by explant culture.Cells at passage 56 were used in experiment.Results The results of in vitro culure showed that cells in both groups grew well.The cells in periodontitis group grew more rapidly than those in healthy group.Histochemical staining and ELISA showed that the cells were positive in ALP staining and the calcium nodules stainning,and that the cultured cells were osteoblasts of alveolar bones.Conclusions Traditional explant culture can be used in isolation and culture of human healthy and periodontitis osteoblasts of alveolar bones.It may be one of identification indexes of periodontitis osteoblasts of alveolar bones.

Objective To study the influence of facial width/length ratios and profile convexity changes on the facial esthetics in male individuals.Methods Threedimensional photo from respectively facial and lateral views of male individuals was selected,which conformed to the aesthetic standards.With Adobe Photoshop CS5 software,male facial width/length ratios from bilateral temporal zygomatic area to mandibular angle were changed into 58%,60%,62%,64%,66%,with changes in widths respectively -2,-4,0,2,4 mm.According to aesthetic plane through the line connecting pronasale and pogonion as the aesthetic standard,profiles was changed into three types:sag,normal and protruded.Match facial images and profile images into 15 groups,and give them to 20 orthodontic doctors for determining VAS scores in the form of questionnaire survey.Data were inputed into SPSS17.0 statistical software and stastically analyzed by 2factor factorial design ANOVA.Results For sag profile,when facial width/length ratios increased,the VAS score decreased; when profile was normal and facial width/length ratio was 62%,the VAS score was the highest (P<0.01); when profile protruded,the VAS scores ranged from high to low by facial width/length ratio:64%> 62%> 66%> 60%>58%(P<0.01).When width/length ratios were 58%,60%,62%,VAS scores′ rank was:normal profile>protruded profile>sag profile.When width/length ratios were 64%,66%,VAS scores′ rank was:protruded profile> normal profile>sag profile(P< 0.01).Conclusions The facial width/length ratio and profile have significant effects on the facial esthetics,and they should be taken into consideration in clinical orthodontic practice.

Objective Evaluate the curative effects of basic fibroblast growth factor in treatment of light recurrent aphthous ulcers.Methods The randomized controlled trials (RCTs) were retrieved about the basic fibroblast growth factor in treatment of light recurrent aphthous ulcers from PubMed,CENTRAL,EMbase,CNKI and WANFANG from January 1,1989 to March 1,2012,and at the same time,the references included in the study were manually selected.After quality evaluation and material extraction by the reviewer,Meta analysis was done to the documents and materials by using software RevMan 5.0.Results 5 RCTs involving 425 patients were included in the study,with 218 cases in the treatment group (using basic fibroblast growth factor) and 207 cases in the control group (using metronidazole,chlorhexidine dexamethasone,and vitamin B).Meta analysis results showed that the pain index,the healing time of the treatment group and recurrent frequency of patients with recurrent light recurrent aphthous ulcers in the treatment group were all better than those in the control group.There was significant difference（P<0.05）.Conclusions Compared with traditional treatment programs,basic fibroblast growth factor can significantly enhance the efficacy of treating light recurrent aphthous ulcers in patients.

Objective To observe the clinical effects of three methods protecting molar teeth during root canal treatment.Methods We applied the orthodontic band,resin fullcrown and steelwire cerclage to protect molar teeth before root canal treatment.Compare the protective effects on molar teeth,looseness,dislocation,and breakage of protective device as well as irritative symptoms at gingivae caused by the three methods.Results The resin fullcrown group and orthodontic band group had obvious difference with steelwire cerclage group in protective effects on molar teeth and irritative symptoms at gingivae as well as looseness,dislocation,and breakage of protective device,while resin fullcrown group and orthodontic band group had no obvious difference with each other.Conclusions Applying resin fullcrown or orthodontic band to molar teeth before root canal treatment can obviously protect molar teeth,avoid crown fracture, and induce less adverse effects than applying steel wire cerclage.

Objective To assess the health statuses and quality of life of patients with recurrent apthous ulcer and performe a preliminary analysis of the influencing factors.Methods This study included a patient group of 65 patients who were diagnosed as RAU and a control group of 65 cases comparable with RAU cases. With the method of case pairing,two groups completed the questionnaires of SF36 and OHIP14 according to requirements.Then analyze the scores, classify them and carry on comparative analysis of two groups. Data on the two groups were processed using SPSS 17.0 software package for statistical analysis. Results In the SF36,the scores of the RAU group such as role limitations caused by physical function, body paining, general health evaluation, vitality and the total scores were lower than the healthy controls（P＜0.05）;and in the OHIP14, the scores of functional limitations, physiological pain, psychological barriers and the total scores in the RAU group were higher than the healthy controls（P＜0.05）.Conclusions The quality of life in patients with recurrent apthous ulcer is worse than that of healthy people. The patient′s quality of life has been affected by disease, psychological adjustment should be paid attention in the clinical.

Objective To clarify the distribution of caries in the first permanent molars of primary school students in Xuzhou, and make analyis to provide reference for oral health care for primary school students.Methods This study adopted the method of crosssectional study.According to the 4th edition of dental health investigation standards of WHO, 3018 primary school students in downtown areas of Xuzhou were surveyed, which included 1565 males and 1453 females.The result was statistically analyzed by SPSS 16.0.Results The total caries prevalence rate of the first permanent molars was 15.11%.The average decayedmissingfilled(DMFT) teeth were 0.283.The permanent caries prevalence increased obviously with age.The caries prevalence of girls was 17.48%, which was higher than that of boys(12.91%), and there was statistically significant difference (P<0.01).The caries prevalence of the first permanent molars in the mandibles were higher than that in the maxillaries.The total caries filling rate was 7.25%.Conclusions The caries prevalence of the first permanent molars in primary school students is high, while the filling rate is low in Xuzhou.Some measures should be taken to prevent and treat caries.