循环加载对牙本质黏结界面纳米渗漏的影响

目的:探讨循环加载对牙本质黏结界面纳米渗漏的影响。方法:选用3种黏结系统:Prime & BondNT(NT),Adper Prompt(AP)和Contax。用扫描电镜(SEM)观察这3种黏结系统在有无循环加载的作用下,牙本质黏结断面银渗漏情况,并用NHl图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价纳米渗漏程度。结果:各对照组银沉积面积的百分比分别为NT(11.48%±2.84%)、AP(21.18%±3.66%)、Contax(14.30%±2.52%),实验组分别为NT(25.20%±4.69%)、AP(38.96%±8.78%)、Contax(29.94%±4.51%)。结论:无论加载与否,所用3种黏结系统都不能避免纳米渗漏的产生;循环加载使黏结系统黏结界面纳米渗漏增加,尤其以AP最为显著。     

人工唾液浸泡对两种牙本质粘接剂粘接界面的影响

目的：探讨含细菌的人工唾液对两种牙本质粘接剂粘接界面纳米渗漏的影响。方法：选用全酸蚀粘接剂Prime Bond NT（NT）与自酸蚀粘接剂Adper Prompt（AP）分别与正常牙本质粘接并制备微拉伸试件,之后将试件浸泡于含细菌的人工唾液中,分别在即刻、1周、1月、3月时取出进行硝酸银染色,用扫描电镜（SEM）观察粘接界面银沉积情况,并用NIH图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价界面纳米渗漏程度。结果：粘接界面在即刻、1周、1月、3月时的银沉积面积百分比分别为NT：（10．97±5．14）％、（12．25±4．01）％、（16．49±4．43）％、（21．03±5．65）％：AP：（17．00±5．40）％、（18．71±6．94）％、（22．81±5．60）％、（26．79±5．77）％。结论：无论浸泡人工唾液与否,粘接试件都无法避免纳米渗漏的产生;含细菌的人工唾液浸泡会影响粘接的稳定性,浸泡3个月即表现出界面银渗漏程度的显著增加。     

人工唾液浸泡对牙本质黏结耐久性的影响

目的:研究人工唾液浸泡对牙本质黏结强度和黏结界面纳米渗漏的影响.方法:选取30个无龋损人磨牙,用600目碳化硅砂纸在流水冲洗下预备牙本质黏结面,分别用3种(Prime&Bond NT,Adper Prompt和Contax)黏结剂进行黏结处理,复合树脂充填.制备黏结面积为Imm2的条形树脂牙本质试件,在人工唾液中分别浸泡1天(对照组)、90天、180天,然后进行硝酸银染色后测定微拉伸黏结强度,场发射扫描电镜下比较界面纳米渗漏.结果:唾液浸泡180天后,Prime&Bond NT和Adper Prompt黏结强度显著小于对照组,界面纳米渗漏百分比与对照组相比显著增加,Contax黏结强度和界面纳米渗漏百分比与对照组无显著变化.结论:"2步法"自酸蚀黏结剂Contax牙本质黏结界面的耐久性优于"1步法"自酸蚀黏结剂AdperPrompt和全酸蚀黏结剂Prime&Bond NT.     

自酸蚀黏结剂的牙本质黏结界面纳米渗漏观察

目的观察并评价3种自酸蚀黏结剂(ClearfilTMSEBond、AdperTMPromptTM、PANAVIATMF)黏结处理后的牙本质纳米渗漏。方法选取9颗无龋坏人磨牙,用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质黏结面玷污层。分别用3种自酸蚀黏结剂按使用说明进行黏结处理。每颗牙齿垂直于黏结面切割出5个0.9mm厚黏结试件,避光贮存于氨化硝酸银溶液中24h,在透射电镜(TEM)下观察牙本质黏结界面纳米渗漏。结果3种自酸蚀黏结剂试件牙本质黏结界面混合层的底部在TEM下均观察到排列规则的银粒子渗漏。结论自酸蚀牙本质黏结界面下可能存在未完全封闭的牙本质脱矿层,存在纳米渗漏。     

3种黏结剂黏结釉质的界面微渗漏研究

目的：评价3种牙齿黏结剂黏结釉质后界面微渗漏情况。方法：离体尖牙或前磨牙60个，在牙齿的唇颊面磨出直径3mm的釉质平面，用黏结剂（Prime＆Bond NT，Xenol Ⅲ，Adper Prompt）黏结釉质平面，并用复合树脂覆盖。24h后在黏结部位中部，以垂直于黏结界面和牙齿长轴的方向切一细槽，深度超过黏结界面。将每种黏结剂黏结的牙齿分为2组，每组10个，其中一组的牙齿进行10000次冷热循环，另一组浸于37℃水中。在牙齿的表面涂指甲油，然后将牙齿浸于500g／L的氨化硝酸银溶液中，24h后取出，再浸于显影液中，8h后取出。将牙齿纵向并垂直于黏结面切成两半，在测量显微镜下测量剖面银从细槽处沿黏结界面渗入的深度，最后在扫描电子显微镜下观察黏结界面处银渗漏情况。结果：Prime＆Bond NT的未冷热循环组与冷热循环组的银渗漏深度无显著差异（P〉0.05），Xenol Ⅲ及Adper Prompt的冷热循环组的银渗漏深度显著大于未冷热循环组（P〈0．01）。3种黏结剂间相比，Prime＆Bond NT的银渗漏显著小于Xenol Ⅲ及AdperPrompt（P〈.01）。结论：自酸蚀黏结剂黏结釉质的密合性差于酸蚀一冲洗型黏结剂，形成的黏结界面的耐老化性能也不好。     

黏结面润湿度对牙本质黏结界面纳米渗漏和黏结强度的影响

目的: 研究、比较不同黏结面湿润度对4种伞酸蚀黏结剂(OptiBond Solo、Single Bond、One-Step、Prime & Bond NT)牙本质黏结界面纳米渗漏和黏结强度的影响.方法:选取60个无龋损人磨牙,用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质黏结面玷污层,分别选用4种黏结剂在不同黏结而湿润度条件下进行黏结处理.每个牙齿垂直于黏结面切割出8个1.0 mm×1.0 mm×4.0 mm黏结试件,分别在TEM下观察其黏结界面纳米渗漏以及进行微拉伸强度(μTBS)测试.结果:4种黏结剂在润湿的黏结面上均取得了最高的牙本质黏结强度和较少的纳米渗漏.结论:通过合理控制黏结面润湿度,可以在提高牙本质黏结强度的同时,减少黏结界面纳米渗漏的产生.     

牙本质黏结界面的微渗漏与纳米渗漏

目的：观察牙本质黏结界面微渗漏与纳米渗漏,探讨两者的关系。方法：在离体人磨牙的颊、舌侧颈部制备盒形单面洞（直径3mm,洞深2mm）,将牙分为2组,每组5个牙。对2组牙的窝洞分别应用黏结剂Single Bond、Clearfil SE Bond,然后充填复合树脂并光照固化。所有牙齿进行冷热循环5000次,之后在牙齿表面涂指甲油。将牙齿浸泡于500g/L氨化硝酸银液（pH8.0）中,24h后再浸泡于显影液中8h。随后将牙纵向剖开,暴露充填物剖面,在体视显微、扫描电镜下观察剖面充填物龈缘渗漏情况。结果：所有牙剖面修复体龈缘均存在程度不同的微渗漏,有微渗漏的黏结界面处并未发现因黏结原因所造成的裂缝或微裂隙,但在混合层内观察到纳米渗漏。结论：牙本质黏结界面的微渗漏染色不一定因界面裂缝所致,界面无裂缝的纳米渗漏同样可造成微渗漏染色。     

循环加载后牙本质粘结强度与界面纳米渗漏之间相关性的研究

目的 研究循环加载后三种牙本质粘结剂界面银渗漏面积与微拉伸粘结强度之间的相关性.方法 36颗新鲜拔除的无龋第三磨牙垂直牙体长轴除去冠部釉质,在牙合面制备盒型洞,随机分成3组,分别用粘结剂粘结Prime&Bond NT(NT)、Adper Prompt(AP)、Contax,复合树脂充填.每组再随机分成实验组和对照组.实验组以50N大小的力进行循环加载.加载10000次.制备测试微拉伸粘结强度的条状试件.硝酸银染色.在拉力试验机上测定粘结强度,并用NlH图像分析软件量化计算界面的银沉积面积百分比.结果 循环加载前,三种粘结剂的界面银渗漏面积与微拉伸粘结强度未表现出明显的相关性(P＞0.05).加载后,界面银渗漏面积与微拉伸强度表现出相关性(P＜0.05).结论 循环加载使三种粘结剂界面的银渗漏面积的增大以及微拉伸粘结强度的降低,并且加载后界面的银渗漏面积与微拉伸粘结强度表现出显著的相关性.     

冷热循环对牙本质粘结耐久性的影响

目的:研究冷热循环对牙本质粘结强度和粘结界面纳米渗漏的影响.方法:选取30个无龋损人磨牙,用600目碳化硅砂纸在流水冲洗下预备牙本质粘结面,分别用3种(Prime&Bond NT,Adper Prompt和Contax)粘结剂进行粘结处理,复合树脂充填.纵向片切牙齿,制备粘结面积为1 mm2的条形树脂牙本质试样.冷热循...     

人工唾液浸泡对两种自酸蚀粘接剂粘接界面的影响

目的探讨含细菌的人工唾液对两种自酸蚀粘接剂粘接界面纳米渗漏的影响。方法选用自酸蚀粘接剂Adper Prompt（AP）和Contax分别与正常牙本质粘接并制备微拉伸试件,之后将试件浸泡于含细菌的人工唾液中,分别在即刻、1周、1月、3月时取出进行硝酸银染色,用扫描电镜（SEM）观察粘接界面银沉积情况,并用NlH图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价界面纳米渗漏程度。结果粘接界面在即刻、1周、1月、3月时的银沉积面积百分比分别为AP：（17.00±5.40）%、（18.71±6.94）%、（22.81±5.60）%、（26.79±5.77）%;Contax：（11.90±5.17）%、（12.41±4.42）%、（14.73±3.46）%、（17.64±5.39）%。结论无论浸泡人工唾液与否,粘接试件都无法避免纳米渗漏的产生;含细菌的人工唾液浸泡会影响粘接的稳定性,其中以AP组的稳定性较差,浸泡三个月即表现出界面银渗漏程度的显著增加。     

替牙期骨性Ⅲ类错牙合患者颞下颌关节特征的锥形束CT研究

目的:采用锥形束CT(CBCT)研究替牙期骨性Ⅲ类错牙合患者颞下颌关节的影像学特征,探讨Ⅲ类功能状态下,颞下颌关节的生长、改建机制。方法:从就诊于昆明医科大学附属口腔医院正畸科的患者中选取符合纳入标准的替牙期骨性Ⅲ类错牙合患者及骨性Ⅰ类错牙合患者各20名,使用NNT viewer 5.3图像处理软件进行三维重建及线距和角度的测量,并进行统计学分析。结果:替牙期骨性Ⅲ类错牙合患者组和替牙期骨性Ⅰ类错牙合患者组对比结果为:矢状面双侧关节前间隙偏小、双侧关节上间隙偏小、双侧关节结节斜度偏小;冠状面双侧关节内间隙偏小,双侧关节上间隙偏小,双侧关节外间隙偏小,右侧髁状突角度偏小;横截面右侧髁状突前后径偏小。结论:替牙期骨性Ⅲ类错牙合患者颞下颌关节发育不充分,呈现髁状突,关节窝深度,关节结节斜度;冠状面关节内、外间隙均较小的特征。骨性Ⅲ类错牙合患者髁状突在关节窝中处于前置近关节窝顶位置。骨性Ⅲ类错牙合患者颞下颌关节影像学特征与其功能状态相适应。     

柠檬精油对牙周致病菌抑制作用及其安全性初步研究

目的:探讨柠檬精油对牙周致病菌的体外抗菌活性及对细胞增殖的影响。方法:采用微量液体稀释法测定柠檬精油对Pg、Fn、Aa、Pi的最小抑菌浓度(minimal inhibitory concentration,MIC)及最小杀菌浓度(minimum bactericidal concentration,MBC);以较低浓度的MIC为标准稀释LEO作为实验组,采用MTT法测定柠檬精油对HUVECs的毒性作用,明确抑菌浓度下LEO的安全性。结果:柠檬精油对牙周主要致病菌均有抑菌作用,Pg、Fn、Aa、Pi的MIC分别是9.0 g/L、4.5 g/L、4.5 g/L、9.0 g/L,Aa、Fn的 MBC是9.0 g/L,Pg、Pi的MBC未测得。1/2MIC、1/20MIC浓度的LEO能够抑制人脐静脉内皮细胞的生长,而低于1/200MIC浓度的LEO则对人脐静脉内皮细胞的生长没有影响,其中1/200MIC浓度的LEO作用明显优于0.02%的CHX。结论:体外环境中,柠檬精油对牙周致病菌Pg、Fn、Aa、Pi具有抗菌活性,低浓度应用对机体相对安全。     

Computer-assisted planning for maxillofacial prosthodontic rehabilitation

Computerized tomography (CT) planning and the use of CT derived surgical templates for implant placement have shown promise for restoring function within months after surgical reconstruction of acquired post-oncologic defects.     

Ghlorhexidine as a root canal medicament for treating inflammatory lesions in the periodontal space

Abstract— The purpose of the present study was to investigate the therapeutic effect of intra-canal application of chlorhexidine on inflammatory root resorption. Dental pulps from monkey incisors were infected and resealed prior to extraction of the teeth. Root dentin was mechanically exposed and the teeth were replanted under aseptic conditions. After 4 weeks, the experimental teeth were dressed with chlorhexidine gel and resealed. Animals were sacrificed 4 weeks later, and their jaws prepared for histologic examination. Results showed that both marginal and apical periodontal inflammation and resorption were reduced in the chlorhexidine-treated teeth. It was concluded that the use of intra-canal chlorhexidine may be a useful adjunct in the treatment of inflammatory root resorption, but further human trials need to be undertaken before its clinical use can be recommended.     

Effect of Pingyangmycin on human venous malformation endothelial cells

Purpose: Venous malformations are common vascular anomalies with a propensity of the head and neck. Intralesional injection of Pingyangmycin (PYM, bleomycin A5 hydrochloride) is a widely used sclerotherapy method for the treatment of venous malformation.     

小鼠牙髓干细胞同种异体移植后体内免疫反应初探

目的:初步探究小鼠牙髓干细胞同种异体移植后的全身免疫反应。方法:牙髓干细胞分离获得自C57BL/6 小鼠牙髓组织,培养至第3 代,与纳米羟基磷灰石(n-HA)复合培养形成复合物,扫描电镜观察其生长黏附情况。40只4周龄的C57BL/6 小鼠随机分成两组。实验组将复合物移植入上背部皮下,对照组将纳米羟基磷灰石植入上背部皮下,术后均使用外科方法严密缝合创口。两组动物术后均观察4周、6周处死,分离脾脏,制成脾淋巴细胞悬液,流式细胞仪测定CD4⁺、CD8⁺的值。结果:牙髓干细胞在体外与纳米羟基磷灰石结合良好;免疫组化染色实验组4周、6周均可见牙本质涎蛋白(dentin sialoprotein,DSP)阳性表达;实验组与对照组相比,术后4周、6周CD4⁺/CD8⁺值均无明显差异。结论:牙髓干细胞同种异体移植后,尚不能够引起机体的免疫排斥反应,其在体内仍具有低免疫原性,有望成为组织工程同种异体种子细胞来源。     

Clinical and pathological aspects on some odontogenic tumors

Odontogenic tumors constitute a very diverse group of lesions that reflects the complex processes of odontogenesis. Controversies over their classification/subtyping, terminology and diagnosis have been persisted, which has direct bearings on therapeutic and/or prognostic implications.     

Cytokine-induced endogenous procollagenase stored in the extracellular matrix of soft connective tissue results in a burst of collagen breakdown following its activation

Numerous data strongly suggest the involvement of cytokines and the matrix metalloproteinase collagenase (MMP-1) in the pathogenesis of periodontitis. Recently, we have demonstrated that, upon culturing under the influence of IL- lα+EGF, a large amount of inactive procollagenase (MMP-1) is stored in the extracellular matrix of periosteal tissue. We now show that this endogenous reservoir of proenzyme can be operative after activation with plasmin and is able to induce a rapid and almost complete breakdown of the collagenous extracellular matrix. The level of collagen degradation following activation showed a strong correlation with the amount of proenzyme that was incorporated in the tissue. The highest levei of degradation (70% of the total amount of collagenous proteins) was found with the IL-lα+EGF-treated explants, followed by those treated with IL-1α alone (35%). Explants cultured with EGF or in the absence of cytokines, containing only small amounts of procollagenase, showed little collagen breakdown following plasmin activation (7%). Inhibition of metalloproteinases by EDTA, or blockage of plasmin by PMSF, prevented the degradation in all explants irrespective of the amount of proenzyme present in the tissue. Our findings demonstrate that endogenous proenzyme stored in a native connective tissue matrix can be activated at a later time interval which results in a massive breakdown of the tissue. This study shows a possible pathway of collagenase-induced breakdown without recent de novo synthesis of the enzyme. Such a sequence may be operative in chronic inflammatory diseases, such as periodontitis, where production of procollagenase under the influence of cytokines spans a longer time period, whereas breakdown is often characterized by a cyclic behaviour.     

Current management of oral cancer

This presentation will summarize some of the current areas of interest in the management of oral cancer. The presentation will be divided into a brief review of epidemiology and diagnosis, with a more extensive discussion regarding the controversial areas in surgery and a review of the adjuvant roles of radiation and chemotherapy.