纤维桩的力学性能和固位的研究

纤维桩树脂核成功应用于临床的重要保证是其优势的力学性能和可靠的固位,故学者们对纤维桩的弯曲强度、抗折载荷和弹性模量以及固位进行了大量的研究。本文就近年来有关纤维桩树脂核修复的生物力学和固位影响因素的研究作一综述。     

纤维桩的表面处理

关于根管桩材料和设计的研究已日益成熟.纤维桩树脂核修复被公认为具有较好的修复效果,现在的研究主要集中在桩核的粘接固位方面.除了对粘接剂的研究外,纤维桩表面处理是增强界面粘接强度的常用方法之一,它可以促进不同成分之间形成化学和机械固位.对纤维桩的表面处理主要为了增强桩在根管内的固位以及桩与树脂核的粘接.本文就此作一综述.     

纤维桩与树脂核材料粘接的研究进展

桩核加冠修复是临床根管治疗后,牙冠外形重建的主要手段之一。纤维/树脂桩核系统具有优良的机械、生物学性能和较好的修复效果,被广泛用于临床。近年来,纤维桩与树脂核材料间的粘接研究成为了热点。纤维桩与树脂核材料间能否形成牢固和持久的化学和机械固位,直接关系到修复体的临床成功率。树脂核材料的种类、纤维桩的种类以及纤维桩的表面处理均会影响纤维桩与树脂核材料间的粘接强度。下面就上述影响因素的研究现状作一综述。     

纤维/树脂桩核的粘接与固位

采用树脂基复合材料制作的纤维桩以优良的理化性能逐渐得到推广和应用,纤维桩采用粘接性树脂水门汀与根管粘接,以树脂材料作核,目前对纤维/树脂桩核的研究热点集中于粘接和固位的研究,本文对此作一综述.     

纤维／树脂桩核的粘接与固位

采用树脂基复合材料制作的纤维桩以优良的理化性能逐渐得到推广和应用，纤维桩采用粘接性树脂水门汀与根管粘接，以树脂材料作核，目前对纤维／树脂桩核的研究热点集中于粘接和固位的研究，本文对此作一综述。     

3种纤维桩修复残冠的临床观察

目的:探讨临床常用的3种玻璃纤维桩在残根残冠修复治疗中的临床效果。方法:148例患者共计161颗残根残冠经完善的根管治疗后采用玻璃纤维桩堆塑树脂核行全冠修复,观察其疗效。结果:经过2年的临床观察,纤维桩核修复成功率为91.93%,10例失败源于桩或冠松脱,其中FibraPost玻璃纤维桩桩核松脱率最低。3例失败表现为桩核折断。结论:纤维桩树脂核可作为理想的残根残冠修复方式,纤维桩表面固位设计以及纤维桩与根管的密合度都可以增强其抗脱位能力。     

不同粘固材料对纤维桩固位力的影响

目的：研究纤维桩钉在用5种不同粘固材料的固位力,为临床选择纤维桩粘固材料提供依据。方法：将纤维桩用5种粘固材料（HY-BOND玻璃离子水门汀;PermaCem双固化树脂水门汀;LuxaCore双固化树脂;Dulink双固化树脂水门汀;Rely-X Unicem双固化树脂水门汀）粘固于离体人牙根管内,万能电子力学试验机测试其固位力,电子探针分析界面情况。结果：纤维桩在用不同粘固材料的固位力由大到小顺序为：Dulink组、PermaCem组、LuxaCore组、Rely-X Unicem组、HY—BOND玻璃离子组,各组间固位力有显著性差异（P〈0．05）。结论：不同类型粘固材料对纤维桩的粘结力不同,树脂水门汀固位力优于玻璃离子水门汀,且显示了良好的粘结完整性。     

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提要：纤维桩-树脂核-冠修复体越来越多用于口腔修复中。树脂核-冠间的黏结力是全冠获得固位力的主要因素之一,而树脂核-水门汀间黏结强度对冠黏结力的获得具有重要影响。本文就树脂成核材料及其临床应用,影响树脂核-水门汀间黏结强度的因素做一综述。     

可塑性纤维树脂桩核在冠桥保存术中的临床应用

目的：探讨可塑性纤维树脂桩核保存冠桥修复体的临床疗效。方法：随机选择33例47颗牙体缺损基牙,经完善的根管治疗后,利用可塑性纤维桩加复合树脂核修复牙体缺损,再将原冠桥修复体粘固使用,并经过0.5-1.5年临床疗效的追踪观察。结果：33例47颗患牙中除有2颗发生桩核松动脱落、1颗发生牙龈充血外,其余牙固位良好,无根折、桩折现象的发生,成功率为93.6%。结论：可塑性纤维树脂桩核保存冠桥的修复效果满意,值得推广。     

纤维桩黏结强度的影响因素

对于冠方牙体组织大量缺损的患牙,通常需要利用桩核来为最终的全冠修复体提供固位与支持.铸造金属桩在临床上已得到普遍应用,随着树脂黏结技术的发展,纤维桩开始越来越多地应用于口腔临床.多数研究结果显示,与铸造金属桩相比,纤维桩具有良好的美观性、抗腐蚀性、抗疲劳性以及生物相容性,且强度、硬度更接近牙体硬组织,因此被认为是金属桩很好的替代品.纤维桩修复成功的关键在于纤维桩与根管牙本质之间以及与树脂核之间形成牢固的黏结.但是,纤维桩的种类、黏结材料的类型、黏结前纤维桩的表面处理、根管内壁牙本质状态、黏结剂涂布工具、医生的临床技术和经验等因素都会对纤维桩的黏结效果产生直接的影响.     

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.     

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。     

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.     

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     

口底癌34例临床分析

目的探讨口底癌的临床特性、治疗方法及预后。方法对我院自1992—2002年住院治疗的34例口底癌患者进行回顾性分析。结果34例口底癌患者中,男28例(82.4%),女6例(17.6%),男女比为4.7∶1,平均发病年龄58岁。发病部位:前口底22例(64.7%),后口底12例(35.3%)。淋巴结转移率41.2%。单纯手术组、化疗加手术组、放疗加手术组、化疗加手术加放疗组的5年生存率分别为45.5%、60.0%、50.0%、62.5%。结论口底癌以中老年患者好发,男性居多。易发生淋巴结转移,综合疗法疗效较好。