树脂加强型玻璃离子水门汀临床初步应用的研究

目的了解树脂加强型玻璃离子水门汀在临床使用的脱落率,探讨树脂加强型玻璃离子水门汀在临床使用的可行性.方法20名正畸初诊患者的上颌左右侧分别使用正畸用树脂加强型玻璃离子水门汀,复合树脂型正畸釉质粘结剂粘结正畸托槽,观察其临床脱落率.结果树脂加强型玻璃离子水门汀粘结托槽的脱落率与临床普遍使用的复合树脂型正畸釉质粘结剂粘结托槽的脱落率相似.结论树脂加强型玻璃离子水门汀可以满足临床需要.     

不同剂型玻璃离子水门汀对牙本质粘结剪切强度的比较

目的:比较不同剂型玻璃离子水门汀对牙本质粘结剪切强度,为临床使用提供参考。方法:临床收集新鲜拔除的磨牙30个,用慢速精密齿科片切机切取颊面浅层牙本质薄片(片厚2 mm),自凝塑料包埋,仅暴露颊侧浅层面作为粘结面,流水冲洗4 s,无油气体吹干,于每个试件的粘结面上固定一直径4 mm,高2 mm成型管。然后将30个试件随机分为3组(每组10个),分别使用RelyXTM Luting Cement(粉液剂型)、GC Fuji PLUS(粉液剂型)和GC Fuji CEM(双糊剂型)3种玻璃离子水门汀进行充填,制作粘结试件后,试件置于盛有人工唾液的容器中37℃24 h,用万能测试机测定每个试件的粘结剪切强度。结果:3种玻璃离子水门汀的粘结剪切强度由底到高分别为:RelyXTM Luting Cement(粉液剂型)(6.163±1.177)MPa、GC Fuji PLUS(粉液剂型)(8.004±0.962)MPa、GC Fuji CEM(双糊剂型)(10.31±0.893)MPa,三者间差异有统计学意义(P<0.05)。结论:双糊剂型玻璃离子水门汀抗粘结剪切强度明显高于两种粉液剂型玻璃离子水门汀,是临床修复治疗的良好选择。     

粘接处理剂对自粘接树脂水门汀和RMGIC的牙本质粘接强度的影响

目的:实验评价牙本质粘接处理剂对自粘接树脂水门汀和树脂加强型玻璃离子水门汀(RMGIC)的牙本质微拉伸粘接强度的影响.方法:选用离体人无龋第三恒磨牙24颗,用低速切片机垂直于牙体长轴方向将磨牙冠(牙合)中1/3交界线处切开待用.实验组牙本质表面涂布牙本质粘接处理剂,对照组不涂粘接处理剂.后将试样分别用自粘接树脂水门汀(Unicem,3M ESPE;seT PP,SDI)或树脂加强型玻璃离子水门汀(Fuji CEM,GC)原位对位粘接.水浴中储存24h后,用低速切片机把样本切割成约1mm×1mm×8mm条状,随后进行微拉伸测试.用扫描电镜观察粘接界面形貌.结果:无论是否使用粘接处理剂,Unicem的牙本质粘接强度显著高于seT PP 和Fuji CEM(P <0.01).与对照组相比,实验组的粘接强度显著提高(P <0.05).结论:粘接处理剂表面处理增强自粘接树脂水门汀及树脂加强型玻璃离子水门汀的牙本质粘接强度.     

3种水门汀早期溶解性比较研究

目的：离体比较临床常用的3种水门汀在早期接触水状况下的溶解情况,并探讨边缘隔湿剂对水门汀溶解性的影响。为临床水门汀应用的远期效果预测提供理论依据。方法：用3M树脂加强型玻璃离子水门汀,登士柏玻璃离子水门汀,松风聚羧酸锌水门汀分别粘接冠与离体牙,并于粘接后3、6、9min后浸泡于人工唾液中,时间持续30d,其间冷热循环3000次,设立隔湿对照组,电镜测量冠边缘粘接剂剩余厚度。结果：3种水门汀的剩余厚度是不同的,树脂加强型水门汀对溶解的改善是显著的。溶解度由低到高依次是3M树脂加强型玻璃离子水门汀,登士柏玻璃离子水门汀,松风聚羧酸锌水门汀。早期接触水对3种水门汀的溶解度均有很大影响,隔湿剂的应用对改善水门汀早期抗溶解性有很大意义。结论：树脂加强型玻璃离子水门汀理化性质稳定,溶解度小,是未来充填剂和粘固剂的良好选择。     

不同pH值的浸泡液对玻璃离子水门汀溶解性的影响

目的 评价四种玻璃离子水门汀的溶解性,探讨浸泡液pH值的不同对玻璃离子水门汀溶解性的影响.方法 将四种玻璃离子水门汀制成直径15 mm、厚1 mm表面光滑平整的圆片共120个(试件分为S组、F组、D组、A组),Paffenbarger重量法测定各组试件在三种浸泡液中的重量改变.结果 S组、D组和A组在乳酸液中的溶解值高于其它两种浸泡液中的溶解值(P＜0.05);而F组在三种浸泡液中的溶解值差异无显著性.结论 浸泡液pH值对玻璃离子溶解性有影响;玻璃离子水门汀所表现出的对浸泡液pH值的敏感性可能与玻璃离子本身的化学组成及亲水性有关.     

四种玻璃离子充填材料释氟性与溶解性的研究

目的 比较4种玻璃离子充填材料短期内氟离子释放能力和溶解性,为临床选择充填材料提供依据.方法 实验选取1种传统型玻璃离子水门汀(SC),2种高强度玻璃离子水门汀FujiⅨ(F9)和Ketac Moler(KM),1种树脂改良型玻璃离子水门汀FujiIILC (F2LC),和1种复合树脂Z100( CR,3M)共5种材...     

树脂加强型玻璃离子水门汀在托槽粘结中的应用

目的探讨两种树脂加强型玻璃离子水门汀对托槽粘结强度的影响。方法收集离体人前磨牙60个,随机分成6组。第1组和第2组(对照组):35%磷酸酸蚀30 s,冲洗、吹干,涂粘结剂,采用光固化复合树脂粘结托槽。第3、4、5、6组:10%聚丙烯酸酸蚀30 s,冲洗,保持潮湿,第3组和第4组采用化学固化型的Fuji Ortho树脂加强型玻璃离子水门汀粘结托槽,第5组和第6组采用光固化型的Fuji Ortho LC树脂加强型玻璃离子水门汀粘结托槽。第1、3、5组进行抗剪强度测定,第24、、6组进行抗张强度测定,测试后观察断面形态。结果光固化复合树脂的抗剪强度高于其他2组,抗张强度各组间差异无显著性。各种材料的抗剪强度均高于抗张强度。在断面形态观察中,第1组与第3组、第5组差异有显著性,其余差异无显著性。结论两种树脂加强型玻璃离子水门汀的抗剪强度低于复合树脂,但能满足临床的需要。     

树脂加强型玻璃离子水门汀抗拉伸粘接性能的研究

目的 研究树脂加强型玻璃离子水门汀(RMGIC)在不同牙面处理条件下,其抗拉伸粘接强度随时间变化的情况,为临床更有效地应用树脂加强型玻璃离子水门汀粘接托槽提供参考.方法 取因正畸原因拔除的人前磨牙150颗,随机分为5组,树脂对照组,GC酸蚀+水润湿组,GC酸蚀+干燥组,GC不酸蚀+水润湿组,GC不酸蚀+干燥组.分别采用不同方式粘接托槽.检测其在粘接后30min、24h、30d的抗拉伸粘接强度及粘接剂残留指数.结果 除GC酸蚀+干燥组在粘接后30min外,两GC酸蚀组的抗拉伸粘接强度均高于同一时间任一GC不酸蚀组(P＜0.01).各实验组在粘接后30d时的抗拉伸粘接强度均高于相同条件下30min时的抗拉伸粘接强度(P＜0.01).GC酸蚀组粘接剂残留指数(ARI)与对照组相当(P＞0.05),而GC不酸蚀组ARI低于对照组(P＜0.01).结论 酸蚀处理有助于提升树脂加强型玻璃离子水门汀GC的抗拉伸粘接强度,其强度基本可以达到传统树脂类粘接剂水平.湿润的粘接环境较干燥的粘接环境更有助于加快RMGIC抗拉伸粘接强度的上升.     

3种无托槽隐形矫治器附件粘接方法的比较研究

目的 比较全酸蚀粘接剂、自酸蚀粘接剂和树脂加强型玻璃离子水门汀3种材料粘接无托槽隐形矫治器附件的操作时间和临床效果。方法 将采用无托槽隐形矫治器矫治的30例错牙合畸形患者（附件156个）随机分为3组,每组10例。A组采用3M Adper Single Bond 2全酸蚀粘接剂和3M Z350纳米充填树脂粘接附件,B组采用3M Adper Easy One自酸蚀粘接剂和3M Z350纳米充填树脂粘接附件,C组直接采用GC Fuji Ortho LC树脂加强型玻璃离子水门汀粘接附件。记录每个附件的操作时间,评价粘接时、治疗1个月和6个月时3组附件的失败情况。结果 C组附件的操作时间较A、B组短（P<0.01）。3组附件之间的粘接失败率无统计学差异（P>0.05）,同一组内不同时间的粘接失败率也无统计学差异（P>0.05）。结论 3种材料粘接附件的稳定性均能达到满意的效果,但树脂加强型玻璃离子水门汀操作简便,更适宜临床推广。     

口腔正畸粘结剂的研究现状

玻璃离子水门汀和树脂类是临床常用的口腔正畸粘结材料,临床应用中发现各种类型粘结剂除有其优点外,尚存在一些不足,因此不断有新型的正畸用粘结剂被研制成功,并在临床上推广应用。树脂加强型玻璃离子水门汀是一种新型粘结材料,大量实验及临床研究已证明其性能的可靠性和实用性。本文就常用三类粘结剂研究现状进行综述。     

Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

Evaluation of efficacy of chemiluminescence for diagnosis of leukoplakia

ObjectiveLeukoplakia is the most common potentially malignant disorder preceding oral cancer. Chemiluminescence has been developed as an adjunct to conventional examination for the diagnosis of these potentially malignant disorders. This study was conducted to assess the efficacy of chemiluminescence in the diagnosis of leukoplakia and to compare the results with histopathological examination.Study designA total of 50 patients with leukoplakia were included from the outpatients attending the Department of Oral Medicine and Radiology, Dental Hospital, Bengaluru, Karnataka, India. These patients were subjected to conventional oral examination followed by chemiluminescent examination with Vizilite (Zila, Fort Collins, CO, USA) and biopsy for histopathological confirmation.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of chemiluminescence were 93.75%, 55.56%, 78.95%, and 83.3%, respectively. The overall accuracy of chemiluminescence was 80%. A statistically significant association was observed between histopathology results and chemiluminescence results.ConclusionAlthough it is an easy, safe, minimal time consuming, and noninvasive technique, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia.     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.     

正畸患者切牙影像失真发生情况分析

目的研究正畸患者曲面体层片上的切牙影像失真发生情况，并分析其原因。 方法从中山大学附属口腔医院放射科影像数据库中选取500例正畸患者的曲面体层片和头影测量侧位片，所有曲面体层片均采用咬合杆投照，分别从切牙牙体影像放大、缩小、牙根变短、根尖模糊等评价指标分析上下颌切牙影像失真的发生情况，在头影测量侧位片上测量中切牙根尖-对颌切牙切缘的距离，探讨切牙影像失真发生的原因。采用SPSS 19.0统计软件对所得数据进行统计学检验。 结果500例患者中，切牙牙体影像正常者共417例，切牙牙体影像失真者共83例，影像失真发生率16.6%，其中切牙牙体影像放大17例、牙体影像缩小0例、牙根变短30例，牙根影像变短伴模糊36例。影像失真患者的根尖-切缘距离大于影像正常的患者，差异有统计学意义（F = 5 187.18，P = 0）；影像失真患者的覆盖值大于影像正常的患者，差异有统计学意义（F>477，P = 0）。 结论严重牙颌面畸形如反 、深覆盖是导致曲面体层片的切牙影像失真的主要原因之一。     

颌骨动静脉畸形的栓塞治疗

目的：总结直接穿刺结合经血管内介入栓塞治疗颌骨动静脉静脉畸形的经验。方法：收治凳骨动静脉畸形患者6例,均进行了介入栓塞治疗。采用的栓塞材料为附凝血棉纤毛的螺圈,聚乙烯醇泡沫微粒和二氰基丙烯酸对丁酯。数字减影颈动脉造影在PHILIPSV300下完成。结果6例颌骨动静脉畸形患者中4,例急性出血得到了快速、有效控制,1例慢性渗血的右下 骨动静脉畸形患者,介入栓塞治疗,拔除松动的右下凳第一磨牙,有效地控制了出血,另1例伴局部软组织搏动性膨隆的上凳骨动静脉畸形患者,介入治疗后膨隆的搏动性得到明显改善,栓塞治疗后分别随访3－24个月,均未发现有口腔内渗血或出血。随访的X线片上,病灶区可见新骨形成。结论：局部穿刺结合经血管内介入栓塞治疗颌骨动静畸形是一种安全、有效的治疗方法。     

5种着色氧化锆陶瓷的细胞毒性评价

目的：对掺杂5种微量着色剂的氧化锆陶瓷的生物安全性进行初步评价.方法：采用四氮唑盐比色法（MTT）细胞毒性评价方法,用5种着色氧化锆陶瓷材料的浸提液体外培养L929小鼠成纤维细胞2 d、4 d、7 d,于倒置相差显微镜下观察细胞形态;用MTT检测各实验组和对照组的吸光度值（OD值）,计算各组细胞的相对增殖率,并按照6级毒性分类法对各实验组进行评级.结果：培养期细胞贴壁生长,细胞形态正常.随着培养天数增加细胞大量增殖,各实验组的毒性评级为0-1级.结论：添加5种微量着色剂的氧化锆陶瓷无细胞毒性,具备体内应用的生物安全基础.