目的 :分析先天缺失2颗下切牙患者的侧貌特征,探讨该类患者拔牙矫治前后的侧貌变化.方法 :收集64例先天缺失2颗下切牙患者的头颅侧位片.64例患者的初诊侧位片用于分析患者的侧貌特征,其中38例患者拔除上颌2颗前磨牙进行矫治,初诊和治疗结束侧位片用于比较矫治前后的侧貌变化.对侧位片进行头影测量(包括硬组织和软组织项目),并对结果进行统计学分析.结果 :与正常值比较,先天缺失2颗下切牙患者覆盖、覆牙合、ANB、U1-NA角、面角、Y轴角、Pg-NB、面突角、软组织面角、H角和颏唇沟至H线距较大,SNB、L1-NB角、L1-NB距、L1-MP、牙合平面角和颏唇沟角较小,差异均有统计学意义(P<0.05);拔牙矫治后,覆盖、覆牙合、U1-NA角、U1-NA距、U1-SN、H角和鼻唇沟至H线距变小,L1-NB角、L1-NB距、L1-M P、牙合平面角、Pg-NB和颏唇沟角变大,差异均有统计学意义(P<0.05).结论 :先天缺失2颗下切牙患者下颌发育不足但颏部发育充足,覆牙合覆盖较大,下颌切牙舌向倾斜,颏唇沟较深较锐.拔除上颌2颗前磨牙矫治后患者侧貌整体面型基本未变,但前牙咬合关系明显改善.

创伤、感染、肿瘤、以及各种先天性疾病是导致骨缺损的主要原因,骨移植作为骨缺损修复的常用手段,其材料包括自体骨、同种异体骨、异种或人工合成骨移植材料.理想的移植材料必须具有足够的成骨能力、骨诱导及骨传导能力.脱钙骨基质(demineralized bone matrix,DBM)作为自体骨移植的替代材料,是去除了无机成分的骨.因具有良好的骨诱导、骨传导及促成骨能力,自1965年Urist[1]首次提出DBM具有骨诱导能力以来,其对于骨缺损的修复一直受到人们的青睐.

慢性牙周炎是是以牙周结缔组织破坏和牙槽骨吸收为特点的一种慢性炎症性疾病,其发病率高达80％以上,是成人失牙的主要原因.虽然口腔卫生指导、龈上洁治术、龈下刮治术和根面平整(scaling and root planing,SRP)等是牙周病最基本而有效的治疗方法,但受到牙齿解剖条件如根分叉病变、牙周袋深度等影响[1,2],单纯SRP常不能彻底消除菌斑微生物,故局部药物治疗成为慢性牙周炎重要的辅助治疗手段之一.为了使局部牙周袋内药物浓度始终稳定保持在有效浓度范围内,且维持更长的作用时间,控释给药的方式较为理想.微球制剂是目前常用的控释给药方法,用于包载小分子药物、多肽蛋白质等生物大分子药物以及疫苗等.药物微球化后,能对药物进行控释,提高药物的稳定性和利用率,降低副作用,且由医师给药,提高了患者依从性,减少给药次数.作为一种新型的药物载体,缓释载药微球具有极大的发展潜力,现就其在慢性牙周炎治疗的应用研究进展综述如下.

目的:比较2种不同拔牙方式矫治前后安氏Ⅱ类1分类错(牙合)青少年患者软硬组织侧貌的变化,为临床治疗提供参考.方法:选择安氏Ⅱ类1分类青少年患者60例,根据不同拔牙方式分为44/44组(拔除4颗第一前磨牙,30例)和44/55组(拔除2颗上颌第一前磨牙和2颗下颌第二前磨牙,30例),应用治疗前后的头颅侧位片测量2组患者软硬组织的相关测量指标(T1和T2)及其差值(T2-T1).结果:与治疗前比较,治疗后2组患者硬组织测量指标中Overjet、SNA、ANB、U1-NA、U1-NA距、U1-SN、NA-PA和A-NP减小(P＜0.01),U1-L1和Pg-NB增大(P＜0.05或P＜0.01);与治疗前比较,治疗后2组患者软组织测量指标中H角、上唇突度、下唇突度、上唇-E线距离、下唇-E线距离和鼻下点-H线距离减小(P＜0.05或P＜0.01),下唇倾角增大(P＜0.01);治疗前后2组患者软硬组织测量指标变化量(T2-T1)比较差异无统计学意义(P＞0.05).结论:2种拔牙方式矫治安氏Ⅱ类1分类错(牙合)青少年患者时对于患者面部软硬组织侧貌的改变无明显差别.

壳聚糖是唯一的天然碱性氨基多糖,海藻酸是一种天然阴离子多聚糖,这两种物质都具有良好的生物相容性,无细胞毒性,具有生物可降解性,是制备微球的良好材料.本文综合阐述了近年来国内外联合利用壳聚糖和海藻酸两种天然高分子物质制备微球的主要方法(包括离子交联法和乳化法),以及海藻酸-壳聚糖微球作为药物载体在生物医药领域的应用.

Based on anion and cation electrostatic load principle, using sodium alginate and chitosan as raw materials, sustained-release microspheres were obtained by the drip method and layer-by-layer self-assembly. The microspheres were then put into a certain percentage of sodium alginate-chitosan solution, and a new kind of scaffold with microspheres embedded in the spongy structure called sustained-release microsphere-type scaffolds was obtained. The influences of the component ratio of the sustained-release microspheres on the porosity, contraction, hydrophilicity and degradation properties of the sustained-release microsphere-type scaffolds were investigated. The pore size was between 140 and 200 mu m analyzed by scanning electron microscopy (SEM). There was no difference in the cytotoxicity text of the scaffold s leachate between the experimental group and the control group. When the component ratio of microspheres was 10%, the scaffolds had the highest porosity ratio(68. 2%-70. 8%), the lowest contraction percentage(4. 4%-5. 2%) and the best hydrophilicity. The less microspheres the scaffolds had, the faster the degradation rate was. For preventing the degradation rate too fast and carrying more medicines, the scaffolds, whose component ratio of microspheres was 20%, are much better. The microsphere-type scaffold material has good plasticity before freeze-drying. The microsphere-type scaffolds provided an example of the combination with sustained-release systems and existing porous scaffold materials.

Lithium ion-doped polyglycerol sebacate scaffold(PGS)-Li was synthesized by adding lithium ions to polyglycerol sebacate(PGS) during its crosslinking process due to the specific effects of lithium ions on periodontal ligament cells, cementoblasts and the eminent performance of PGS. The molecular mass, composition, structure, porosity, thermal properties, and hydrophilicity of the composite were characterized by gel permeation chromatography(GPC), Fourier transform infrared spectroscopy(FTIR), inductively coupled plasma optical emission spectrometer(ICP-OES), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), thermogravimetric analyzer(TGA) and contact angle measurments, and the degradation of the material was evaluated by in vitro degradation experiments. The biological activity of PGS-Li scaffold was detected by calcein-AM staining and cytotoxicity test. The results indicate that PGS-Li scaffold has been successfully synthesized, which has similar composition and structure to PGS, but slightly larger molecular weight. In addition, the porosity and pore size of PGS-Li scaffold basically meet the requirements of engineering scaffold materials and the seaffold shows better performance in terms of hydrophilicity and thermal stability than PGS. In vitro degradation experimental results show that the degradation rate of PGS-Li scaffold is higher than that of PGS. What's more, the results of cytotoxicity test and cell staining show that there is no significant difference in the proliferation and cell morphology of cementoblasts.

Objective:To compare the stress magnitude and distribution of residual dentin in mandibular first molar restored with endocrown or post-core crown using three-dimension finite element methods. Methods:The three-dimensional finite element models of mandibular first molar were established after scanning by CT. A complete tooth was set as the control group. After simulating root canal therapy, three experimental group models with three kinds of defects were set as the experimental group:defect of mesial and distal proximal surface (group A);defect of buccal and mesial proximal surface (group B);defect of buccal, mesial, and distal proximal surface (group C). Then, endocrowns and post-core crowns were used to restore the defects. A load of 200 N, simulating intercuspal occlusion, was applied vertically to the occlusal surface, and a load of 200 Nsimulating lateral occlusion was applied to the occlusal surface with a 45°angle to the long axis of the tooth. Von Mises stresses and max principal stresses were calculated by Abaqus software. Results:The stress of tooth tissue restored by endocrown was higher than that of post-core crown even more than 1 times. The stress of endocrown was concentrated in the pulp floor, and that of the post-core crown was concentrated in the distal apical 1/3. Conclusion:Endocrown and post-core crown are both applicable for mandibular first molar with large area defect, however, the post-core crown has better protective effect for the tooth tissue.

根管治疗是治疗牙髓炎及根尖周病的主要手段,其操作精细、器械多样、步骤复杂,需要医护之间的密切配合,以提高工作效率,保证医疗质量,防止交叉感染[1].随着口腔诊疗技术的迅速发展,一种新兴的医护配合模式--"四手操作"护理模式正逐渐在国内口腔多个专业推广,尤其在根管治疗中应用,并取得了良好的效果[2-4].

Objective:To observe the clinical effects of split post crown and split post-core crown in restoring the molars with low occlusogingival distance and large root furcation,and to clarify its advantages and analyze its improvement methods.Methods:Forty-nine molars of twenty-nine patients,which had been completely treated with root canal therapy,were restored by split post crown or split post-core crown according to their wills.Split post crown was used in twenty-three cases,and split post core crown was applied in the other twenty-six cases.The clinical effects of the patients in two groups were observed after 12 and 24 months follow-up.The levels of MMP-8 in gingival crevicular fluid were checked and compared 12 months after restoration.Results:The restoration success rates of split post crown were 95.7％ after 12-month treatment and 82.6 ％ after 24-month treatment,respectively;there was no significant difference between them (P＞ 0.05).The success rates of split post-core crown were 84.6％ after 12-month treatment and 52.2％ after 24-month treatment,respectively;there was significant difference between them (P＜0.05).The success rate of split post crown was significantly higher than that of split post-core crown after 24-month treatment (P＜0.05).The levels of MMP-8 in gingival crevicular fluid of the patients were close to each other,there was no statistical significance (P＞0.05).Conclusion;The split post crown shows better clinical effect in restoring the molars with low occlusogingival distance in 24 months than split postcore crown.Targeted improvement will help to improve the clinical success rate.

Objective:To study the expression characteristics of Dickkopf1 (DKK1) in different time and space during tooth development of the postnatal mice, and to provide the theoretical basis for clarifying the mechanism of Wnt signaling pathway in regulating the tooth development.Methods:The postnatal Kunming mice at days 0.5, 6.5, 12.5, 18.5, 24.5, and 30.5 respectively after birth were selected and divided into various groups by time,three in each group.The mice in each group were sacrificed and the paraffin sections of mandibular bone including the first molar were prepared at the thickness of 5 μm, followed by HE staining and immunohistochemical staining in order to detect the expressions of DKK1 in tooth tissue and periodontal tissue.Results:At 0.5 d after birth, the mandibular first molar tooth germ was in the bell stage.At 6.5 d the enamel development of mandibular first molar was almost completed, and the epithelium root sheath extended to the root direction.At 12.5 d the dentin development of crown was completed, with the root formatted about 1/3. At 18.5 d the root had formatted about 2/3.At 24.5 d the root had reached the full length.At 30.5 d the apical foramen was narrow, and the root development was basically completed.There was no DKK1 expression at 0.5 d, but it expressed in the odontoblasts and predentin at 6.5 d. From days 12.5 to 30.5,the expressions of DKK1 were positive in periodontal ligament, alveolar bone, and cellular cementum as odontoblasts, which were gradually increased with the prolongation of time.However, no expression of DKK1 was detected in the pulp.Conclusion:DKK1 shows regular expressions at different tooth developmental stages after birth, suggesting its potential role in the growth of dentin and periodontal tissues.

采用高温热注入法，以P[N（CH 3 ） 2 ] 3 为磷源合成了具有近红外荧光的Ag：InP/ZnSe纳米晶.采用紫外-可见-近红外吸收光谱（UV-Vis-NIR）、荧光光谱、透射电子显微镜（TEM）、X射线衍射（XRD）等对产物的结构和光学性质进行了表征，并分析了Ag掺杂浓度和温度对InP纳米晶荧光性能的影响.通过调节Ag掺杂浓度和反应温度，发现当Ag掺杂量为6%，反应温度为200℃时，Ag：InP纳米晶的发光效率最高.将制备的Ag：InP的表面包覆ZnSe，粒子的荧光效率从原来的20%提高到45%.将具有近红外荧光的Ag：InP/ZnSe纳米晶应用于细胞成像，结果表明制备的荧光纳米晶在细胞成像中清晰可见且毒性较低.

目的:为选择制备卡铂缓释微粒的材料提供参考.方法:以"卡铂""缓释""微粒""Carboplatin""Release""Microparticle"等为关键词,组合查询1997年1月-2017年4月在中国知网、PubMed、Web of Science、Elsevier等数据库中的相关文献,对常用的制备卡铂缓释微粒的材料特点、制备方法及国内外相关研究等方面进行综述.结果与结论:共检索到相关文献193篇,其中有效文献26篇.常用的制备卡铂缓释微粒的材料有聚乳酸-羟基乙酸共聚物(PLGA)、聚己内酯(PCL)、明胶、海藻酸盐/壳聚糖及其他材料.PLGA的降解时间可通过改变丙交酯和乙交酯的比例使其从几天变到几年,可通过更复杂的表面修饰使PLGA微粒的靶向性更强、到达靶器官的药物浓度更高.但PLGA的制备方法目前难以应用于大规模的生产,其重现性和稳定性还有待提高.PCL不仅可主动和被动地靶向肿瘤组织,而且能避免卡铂给药的溶血副作用.但PCL目前的研究均是在体外及动物体内进行,进入人体的研究相对较少.明胶材料的优点包括易乳化、水溶性、成膜、弹性和天然可生物降解,然而其微粒普遍表现出突释现象,想要制备出缓释性能更好的传递系统,需要与其他材料联合应用.海藻酸钠/壳聚糖微粒能有效地保留高分子的生物活性,作为负载各种药剂及食品抗菌剂的包埋材料在医药、食品工业和化妆品等领域中具有良好的应用前景.但对于卡铂的包载,其受到氯离子的影响,包封率较低.虽然每种缓释材料的特性不同,对卡铂的包载程度不一,但制备出的缓释微粒均比卡铂溶液具有更稳定的化学性质、更长的缓释时间、更强的靶向作用以及更低的全身毒性.今后应从卡铂缓释微粒载药量和包封率的进一步提高、药物释放速率及缓释时间的精确控制、缓释体系的表面改性及多种缓释体系的联合应用等方面进行深入研究.

Objective:To make the fixed partial dentures with different materials and the magnetic resonance imaging (MRI)examination of head and neck was carried out to investigate the effects of fixed partial dentures on MRI.Methods:A qualified volunteer was recruited,who was conventionally restored using fixed partial denture. Co-Cr alloy,Au-Pt alloy and Zirconia were chosen as the inner crown materials,respectively.Three kinds of fixed partial dentures were put into the mouth of patient,and 2 kinds of MRI scan sequences (T1-TSE and T2-TSE) were performed.The scanning images without restorations were used as controls.The change of shape,image signal and involving layers of artifacts of different materials in three groups were observed.The maximum diameter of artifact of three materials in coronal, sagittal and axial images were detected. The safeties of fixed partial dentures were observed. Results: The artifacts were found in all the restorations and showed the changes of strengthen and weaken of the signal and the changs of shapes of images.The range of artifacts was the largest in the involved central plane and varied in sagittal,coronal and axial images. The number of involving layers of artifacts in Co-Cr alloy group was significantly more than those in Au-Pt alloy and Zirconia groups;the artifacts were limited in the repaired lateral maxillofacial region without the cervical spine and head region involvement.The artifacts in Co-Cr alloy group involved or slightly involved in all adjacent tissues,and the artifacts in Au-Pt alloy and Zirconia groups only slightly affected the mandibular teeth,lingual muscles and maxillary crowns.The maximum diameter of artifacts in Co-Cr alloy group was larger than those in Au-Pt alloy group and Zirconia group (P <0.05). No displacement was found in the prosthesis,and the patient had no discomfort.Conclusion:The artifact of the fixed partial denture can be seen in MRI examination.Co-Cr alloy or zirconia can significantly reduce the effect of artifact.Fixed adhesive prosthesis in mouth does not affect the safety of MRI examination.

Objective:To investigate the effects of ursolic acid (UA) on the proliferation and differentiation of osteoclasts (OC), and to explore its role in orthodontic force-induced root resorption and its relationship with OC.Methods:The mononuclear / macrophage cells RAW264.7 were induced to the OC.Tacrolimus acid phosphatase (TRAP) staining and bone resorption lacunae observation were used to identify the induction.CCK-8 method was used to select the appropriate concentration of UA for RAW264.7 cell-free biotoxicity and to observe its effect on the proliferation and differentiation of RAW264.7.In experimental groups, UA with gradient concentrations (1.0,2.5,5.0,10.0,20.0and 40.0 μmol·L-1)were added.UA was not added in control group.Results:The TRAP staining and bone resorption lacunae observation showed that after the RAW264.7 cells were induced for 5 d, the TRAP staining positive cells were found;the resorption lacunae were rounded,and oval, etc,the bottom wall was coarser,and the boundary was clear,which indicated that the RAW264.7 cells were successfully differentiated into the osteoclasts.The CCK-8 detection results showed that high concentration of UA (> 10.0 μmol·L-1) significantly inhibited the proliferation of OC;the appropriate concentration of UA (5.0 μmol·L-1) was in the biological safety concentration range and could inhibit the OC proliferation;low concentration of UA (<2.5 μmol·L-1) had no effect.Conclusion:RANKL can induce the differentiation and maturation of RAW264.7 cells.UA is correlated with the proliferation and differentiation of OC;UA has inhibitory effect on OC at the appropriate concentration (5.0 μmol·L-1) in a time-dependent manner.

Objective:To prepare the multilayer alginate chitosan microspheres loading vascular endothelial growth factor (VEGF) and vancomycin (VAN), and to study in vitro release characteristics.Methods:The microspheres were prepared by emulsion cross-linking and self-assembly techniques.The effects of sodium alginate concentration, calcium chloride concentration, oil/water ratio and span80 concentration on the entrapment efficiency(EE) and drug loading(DL) of VEGF and VAN were investigated by orthogonal experimental design to optimize the preparation process.The surface morphology and particle size of microspheres were observed by scanning electron microscope (SEM).Self-assembly was detected by Fourier transform infrared spectroscope (FTIR).The EE, DL and in vitro release of VEGF and VAN were detected by ELISA double antibody sandwich method and ultraviolet spectrophotometry,and the cumulative release curve was drawn.Results:The prepared microspheres were yellowish brown powder.The SEM results showed that the microspheres were spherical, the surface was smoothy, and the dispersity was better.The average particle size was about 50 μm.Sodium alginate concentration of 1.0 g·mL-1, CaCl2 concentration of 8 g·mL-1, oil to water ratio of 3∶1, and span80 concentration of 2% were the best formula.The EE of VEGF and VAN were 49.63% and 16.67%, respectively.In vitro, the cumulative release last 16.5 d and 12.5 d respectively and the amount reached up to 95%.Conclusion:The multilayer alginate chitosan microspheres loading VEGF and VAN present several advantages, such as smaller particle size, higher EE and better controlled release.

Ag : InP nanocrystals with near-infrared ( NIR ) luminescence properties were synthesized and characterized by means of UV-Vis-NIR absorption spectroscopy, transmission electron microscopy( TEM) and X-ray powder diffraction( XRD) . When Ag doping amount was 6％ and doping temperature was 200 ℃, the Ag:InP nanocrystals have the highest luminous efficiency. The emission of as-prepared samples was tunable in the near infrared region by tuning the size of samples. After the surface of Ag: InP nanocrystals was coated with ZnSe, the stability of the particles was improved, and the fluorescence efficiency of the particles was increased from 20％ to 45％. Also, the biomedical imaging results indicated that as-prepared Ag: InP/ZnS nanocrystals could be a nice carrier with low toxicity.

Objective:To investigate the influence of multilayer alginate chitosan sustained-release microspheres loading vascular endothelial growth factor(VEGF) and vancomycin in the proliferation and osteogenic differentiation of human plaacenta-derived mesen chymal stem cells(HPMSCs),and to provide theoretical basis for its clinical application in the repair of bone defect.Methods:The microspheres were prepared based on the previous research and HPMSCs were co-cultured with drug (VEGF/vancomycin)-loaded microspheres (drug-loaded microspheres+HPMSCs group), non-drug loaded microspheres (microspheres+HPMSCs group) and without any microspheres (HPMSCs group).Then the proliferation rate of HPMSCs was identified by CCK-8 kit.The osteogenic differentiation potential of HPMSCs was detected by Alizarin red staining and alkaline phosphatase (ALP) kit when the HPMSCs had been co-cultured with drug loaded microspheres in osteogenic medium (HPMSCs+drug-loaded microspheres+induction group), non-drug loaded microspheres in osteogenic medium (HPMSCs+microspheres+induction group), without any microspheres in osteogenic medium (HPMSCs+induction group) and without any micropheres in normal medium (HPMSCs+PBS group) for 21 d.Results:Compared with HPMSCs group,the proliferation rates of HPMSCs in drug-loaded microspheres+HPMSCs and microspheres+HPMSCs groups had no significant changes (P>0.05).The calcium deposition in HPMSCs+drug-loaded microspheres+induction group was more than those in microspheress+HPMSCs+indution group and HPMSCs+induction group after Aalizarin red staining;the ALP activity in drug-loaded microspheres+HPMSCs+indution group was higher than those in microspheres+HPMSCs+indution group and HPMSCs+induction group (P<0.05),and the ALP activity in microspheres+HPMSCs+induction group was higher than that in HPMSCs+induction group(P<0.05).Conclusion:The sustained-release microspheres loading VEGF and vancomycin have no significant effect on the proliferation activity of HPMSCs and the microspheres could stimulate the osteogenic differentiation of HPMSCs.

Objective:To study the changes of oral health indexes in adolescent orthodontic patients under different brushing time, and to provide basis for the orthodontists to give effective dental health promotion in clinic.Methods:A total of 123 adolescent orthodontic patients were included, and they were divided into 1-3min, 3-5 min, 5-7 min and 7-10 min groups based on the brushing time recorded in the period of orthodontic treatment.The relationship between different brushing time and oral health indexes was evaluated 1,3,and 6 months after experiment, such as sulcus bleeding index(SBI),plaque index(PLI), debris index-simplified(DI-S) and enamel demineralization index(EDI).Results:Compared with 1-3 min and 3-5 min groups, the SBI, PLI, and DI-S of the patients in 5-7 min group were significantly reduced(P<0.05).There was no significant differences of SBI, PLI, DI-S , and EDI between 5-7 min group and 7-10 min group (P>0.05).Conclusion:Brushing teeth more than 5 min can improve the oral hygiene significantly and the best time is 5-7 min;the orthodontists should require the patients to brush teeth at least for 5 min.

Objective:To explore the protein component changes in human placenta--derived mesenchymal stem cells (hPDMSCs) transfected with LIM mineralization protein-1 (LMP-1) gene using proteomics technologies.Methods:The hPDMSCsLMP-1 and hPDMSCsvector were collected to extract total proteins.The two-dimen sional gel electrophoresis (2-DE) of total proteins in cells of two groups was created.The 2-DE map was analyzed and compared using PDQuest software to find out differentially expressed protein spots.These differentially expressed candidate proteins were identified by matrix-assisted laser desorption-ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS).Six protein spots (PCNA,vimentin,annexin A1,annexin A2,eEF2 and peroxiredoxin-1) which were closely related to osteogenesis and had a higher MALDI-TOF-MS-MS score were selected and detected by Western blotting.Results:The 2-DE maps of total proteins in cells were successfully established.Twenty-two differentially expressed protein spots with a difference in expression between hPDMSCsLMP 1 and hPDMSCsvector were identified by PDQuest 2-D Analysis Software.Combination of MALDI -TOF-MS and database search identified a total of 15 differentially expressed protein spots.Of all the identified protein spots,9 proteins were up-regulated and 6 proteins were down-regulated in hPDMSCsLMP-1 as compared with the hPDMSCsvector.Western blot results were fully consistent with proteomics.Conclusion:Fifteen differentially expressed proteins in hPDMSCsLMP-1 were identified.They were potentially important participants in osteogenic differentiation,laid the foundation for further molecular mechanism elucidation of LMP-1 on hPDMSCs cell function and osteogenic differentiation.