不同固化方式对ZY一1硅橡胶与丙烯酸树脂粘结强度的影响

目的：探讨赝复硅橡胶固化方式的不同对丙烯酸树脂与硅橡胶粘接强度的影响。方法：将硅橡胶与已预1处理丙烯酸树脂材料分别在室温,升温,及微波3种不同情况下制成硅橡胶一偶联剂一丙烯酸树脂粘接试件,测试试件粘接强度。结果：3种固化方式下各组间硅橡胶与丙烯酸树脂的粘结强度没有统计学差异。不同功率微波对硅橡胶固化后与丙烯酸树脂粘结强度的影响也没有统计学差异。结论：临床制作需要丙烯酸树脂固定的硅橡胶赝复体时,可以通过不同的固化方式制作。微波固化可以作为一种新的方式应用于赝复体的制作。     

ZA-1偶联剂对赝复硅橡胶与丙烯酸树脂材料粘接强度的影响

目的：研究ZA-1偶联剂在两种加成型硅橡胶及两种丙烯酸树脂之间交叉使用时粘接强度的影响。方法：选择ZY—1硅橡胶与A-2186硅橡胶分别与临床中常用的热凝丙烯酸树脂和自凝型树脂制成硅橡胶一偶联剂一丙烯酸树脂粘接试件,分别测试试件粘接强度。选择ZY-1组进行热氧老化试验。结果：四组硅橡胶偶联剂粘接系统中,ZY-1硅橡胶与丙烯酸树脂的粘接强度显著高于A-2186组（P〈0．05）。热凝和自凝丙烯酸树脂对粘接系统的粘接强度无显著影响。所有实验组的破坏方式均为内聚破坏。热氧老化处理后ZY-1丙烯酸树脂粘接试件的粘接强度与未老化组相比有显著性提高。结论：丙烯酸树脂材料的种类对粘接强度的影响不大。两种不同的加成型硅橡胶与ZA-1偶联剂交叉使用时粘接强度略有下降,但粘接效果不影响临床使用。热氧加速老化实验使ZY-1加成型硅橡胶与丙烯酸树脂的粘接强度有所提高。     

底涂剂对硅橡胶与丙烯酸树脂材料黏结强度的影响

目的:比较不同底涂剂对硅橡胶和丙烯酸树脂黏结强度的影响。方法:取丙烯酸树脂试件8组,其中6组涂不同配方的自制底涂剂,1组涂Cosmesil G611底涂剂,对照组不涂底涂剂,晾干后,与硅橡胶黏结,测试其抗剪强度。应用傅立叶变换红外光谱法对D配方底涂剂的特征吸收谱带进行分析。结果:D配方底涂剂可产生2.20MPa的抗剪强度,Cosmesil G611底涂剂组的抗剪强度为1.44MPa,不涂底涂剂组没有任何黏结力。结论:γ-MPS的浓度与二者的黏结强度密切相关,D配方底涂剂组硅橡胶和丙烯酸树脂间的黏结强度最高。     

树脂表面机械处理方式对硅橡胶与丙烯酸树脂粘结强度的影响

目的：比较不同树脂表面机械处理方式对硅橡胶与丙烯酸树脂粘结强度的影响。方法：按丙烯酸树脂处理方式不同分为9组,7组为砂纸打磨组,分别采用80目,240目,400目,600目,800目,1000目,1500目砂纸流水下均匀打磨,1组为抛光组,1组为喷砂组。各组处理后涂底涂剂,与硅橡胶粘结,测试其抗剪切强度,观察其破坏方式。测试每组部分试片的粗糙度。结果：抗剪切强度基本上与处理表面的粗糙度呈负相关,喷砂组的抗剪切强度最高,达2．46MPa。结论：树脂表面机械处理方式不同会对硅橡胶与丙烯酸树脂粘结强度产生影响,其中以喷砂方式处理可以获得最高的抗剪切强度。     

不同表面处理方式对丙烯酸树脂表面性状和粘接强度的影响

目的探讨不同表面处理方式对丙烯酸树脂表面性状和粘接强度的影响。方法制备硅橡胶与丙烯酸树脂构成的重叠联合模型。根据树脂条的不同表面处理方式,将模型随机分为4组:对照组、MMA浸润组、喷砂组、MMA浸润+喷砂组。用扫描电镜观察各组树脂处理后的表面形态变化,用粗糙度仪检测其粗糙度,万能材料试验机测定树脂条和硅橡胶之间的粘接强度。结果 1.电镜观察显示,未经处理的树脂条表面打磨痕迹明显,经过MMA浸润后,表面出现溶解的痕迹,经过喷砂后,表面粗糙凸凹不平;2.粗糙度:喷砂组(3.12±0.02)μm和MMA浸润+喷砂组(3.11±0.01)μm>对照组(0.73±0.01)μm和MMA浸润组(0.71±0.01)μm,且差异有统计学意义(P<0.05);3.粘接强度:MMA浸润+喷砂组(2.34±0.03)MPa>喷砂组(2.02±0.01)MPa>MMA浸润组(1.81±0.02)MPa>对照组(1.50±0.01)MPa,且差异有统计学意义(P<0.05)。结论 MMA单体浸润与喷砂的处理方式可以使丙烯酸树脂表面的形貌发生变化,更有利于硅橡胶与丙烯酸树脂的结合,获到良好的粘接效果,可在临床推广使用。     

软衬及赝复硅橡胶与基托树脂的粘结及影响因素

口腔软衬及赝复硅橡胶材料与基托树脂材料间的粘结是通过粘结性偶联剂来实现的,二者的粘结受多种因素影响。该文对软衬硅橡胶材料和赝复硅橡胶材料进行概述,同时对硅橡胶与基托树脂材料粘结强度的影响因素作简要综述。     

丙烯酸树脂牙与树脂及陶瓷材料相对磨耗的体外研究

目的：比较成品丙烯酸树脂牙与丙烯酸树脂、Targis及Artglass复合树脂、陶瓷材料的相对磨耗性,为临床选择修复材料提供依据。方法：制作成品丙烯酸树脂牙的牙尖形状标本40个,选择丙烯酸树脂、Targis及Artglass复合树脂、陶瓷4种材料进行相对磨耗实验,每种材料均制作块状标本10个。在自制磨耗装置上循环磨耗50000次后测试各种标本的高度丧失。结果：丙烯酸树脂牙牙尖磨耗度由大到小分别为：陶瓷、复合树脂、丙烯酸树脂。丙烯酸树脂、复合树脂、陶瓷的磨耗度由大到小分别为：陶瓷、丙烯酸树脂、复合树脂。结论：陶瓷与丙烯酸树脂牙相对磨耗时,树脂牙的磨损较大,临床上应避免使用将陶瓷与树脂作为相对磨耗材料,复合树脂是丙烯酸树脂牙较为理想的对颌修复材料。     

高强玻璃纤维／树脂复合材料的力学性能研究

目的研究高强玻璃纤维增强丙烯酸类树脂的力学性能。方法按要求制作丙烯酸树脂浇铸体,测试其强度;将高强玻璃纤维按39.5%、48.7%、56.8%、72.4%质量分数,与丙烯酸树脂制成单向纤维/树脂复合材料,并测试其弯曲强度、弯曲模量和层间剪切强度。结果随着纤维含量增加,复合材料的弯曲强度和弯曲模量呈显著性增加(P<0.05),可达弯曲强度(1414.7±64.5)MPa,弯曲模量(39.6±1.6)Gpa;层间剪切强度呈先升后降趋势(P<0.01),最低为(58.7±4.4)MPa。结论高强玻璃纤维对丙烯酸树脂的弯曲性能具有增强作用。复合材料的纤维含量不应过高。     

树脂表面形态处理对义齿软衬材料粘结性能的影响

目的：探索一种增进硅橡胶软衬材料和基托粘结力的可靠方法,促进软衬材料的临床应用。方法：利用模具制作两组树脂基托板：平面基托板和有凸起的基托板,以silagum硅橡胶软衬材料为夹心,平板对平板、凸板对凸板分别制作＂三明治＂样结构,采用改良的＂L＂形拉伸撕脱试验测试两组试件的粘结功并记录撕脱方式,所得试验数据经统计学分析（a=0.05）。结果：凸起组的的粘结功明显大于平面组的粘结功,二者间的差异具有统计学意义（P〈0.05）。平面组的破坏形式以粘结性破坏为主;凸起组的破坏形式以内聚性破坏和混合性破坏为主。结论：改变树脂基托表面的形态增大接触面积及嵌合力可以增大硅橡胶软衬材料和丙烯酸树脂之间的粘结强度。     

偶联剂ZA-1的研制

目的 研制ZY-1加成型硅橡胶与丙烯酸树脂支架粘结用的复合偶联剂.方法 在大量预试验的基础上筛选了5种配方,最后配置成甲基氢硅氧烷低聚物和双官能团硅烷低聚物两种偶联剂,通过拉伸剪切实验,筛选最终配方.结果 使用双官能团硅烷低聚物偶联剂可以大大提高硅橡胶和丙烯酸树脂的粘结,其增粘效果明显优于甲基氢硅氧烷低聚物偶联剂,最高粘结强度为1.98 MPa.结论 研制出偶联剂ZA-1,其主要成分为γ-MPS和四甲基二乙烯基二硅氧烷.     

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.     

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.     

不同剂型玻璃离子水门汀溶解性比较研究

目的:研究、比较不同剂型玻璃离子水门汀的溶解性和表面微观形态改变,为临床使用提供依据.方法:将3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)及GC玻璃离子水门汀(双糊剂型)分别在人工唾液中浸泡30 d,冷热循环15000次,烘干测重,比较前后质量变化,计算溶解率,并用扫描电镜观察表面微观改变.结果:不同剂型的玻璃离子水门汀溶解率由高到低分别为3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(双糊剂型).3种玻璃离子水门汀经浸泡溶解后,SEM扫描表面微观形态可观察到GE玻璃离子水门汀(双糊剂型)表面形态改变较少,其他2组玻璃离子水门汀表面微观改变较多.结论:双糊剂型玻璃离子水门汀理化性能及溶解率均低于传统水粉剂型,是未来临床修复治疗的的良好选择.     

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.     

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.     

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。     

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。     

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。     

鼻测量法的进展

唇裂术后继发畸形是指唇裂修复术后,仍遗留或继发于手术操作和生长发育变化而表现出来的一类畸形[1]。包括唇畸形、鼻畸形和颌骨畸形。其修复较原发性唇裂修复更复杂,更灵活多变。而导致其修复复杂性的一个重要原因即是局部组织结构复杂变异和缺乏可靠的三维测量手段[2],鼻畸形