首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
目的通过对《口腔医学》2007年全年文献的回顾和分析,了解我国口腔临床医学的研究现状。方法阅读2007年《口腔医学》全年的文献,对各种信息进行了分类汇总,根据设计类型对临床一次性文献进行了分类,并对其中的试验性研究文章进行质量分析。结果《口腔医学》2007年全年的一次性文献274篇,基础和临床文献分别为108和166篇,以临床文献为主(60.58%)。在临床研究文献中,属于观察性、分析性和试验性的文献分别为97、9和60篇,观察性文献所占比例为36.14%,高于以往的报道。60篇观察性文献中,全都设有对照;统计方法应用得当者44篇;真正做到随机、盲法的分别只有4和2篇。结论我国口腔临床方面的研究水平近年来提高明显,但设计的科学性方面有待提高。  相似文献   

5.
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 dE1/2/dpH and pKa-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.  相似文献   

6.
口腔医学专业本科毕业生就业现状的调查分析和教育思考   总被引:4,自引:0,他引:4  
目的研究口腔医学专业的教学如何面向市场,推出令用人单位满意的人才。方法采用问卷调查的方法对浙江省内有代表性的19家包含口腔医疗服务单位进行了调查,同时进行大学生就业心态调查问卷调查。结果医学生的就业心态出现多元化;毕业生不再一味追求高学历,更多的人选择了先就业后进修的道路。大多数用人单位着眼于提高医务人员的服务水平和质量,对毕业生的综合素质有了更高的要求。结论学校要尽力拓宽毕学生的就业渠道,提供更多的就业信息,树立面向基层的观念。  相似文献   

7.
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。  相似文献   

8.
9.
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.  相似文献   

10.
口底癌34例临床分析   总被引:1,自引:0,他引:1  
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。  相似文献   

11.
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.  相似文献   

12.
目的 对作者研制的一种新型含钙云母玻璃陶瓷PMC Ⅰ型陶瓷的可切削性能与VitaMKⅡ陶瓷进行定量比较 ,探讨PMC Ⅰ型陶瓷强度与其可切削性的关系。方法 采用钻孔实验方法 ,测定A、B、C、D4组不同晶化处理的PMC Ⅰ型陶瓷及VitaMKⅡ陶瓷材料 60 0s的钻孔深度 ,同时测定4组PMC Ⅰ型陶瓷的 3点抗弯强度。结果 VitaMKⅡ的钻孔深度为 0 71mm ;4组PMC Ⅰ型陶瓷的钻孔深度分别为 0 88mm、1 40mm、0 40mm和 0 90mm。其中 ,B组样品与其余组别及VitaMKⅡ陶瓷的差异有显著性 (P <0 0 5)。 4组PMC Ⅰ型陶瓷的 3点抗弯强度分别为 1 37 7、2 1 0 2、1 1 8 0和 1 0 6 0MPa。结论 新型PMC Ⅰ型切削陶瓷的可切削性已能够满足临床要求  相似文献   

13.
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。  相似文献   

14.
5种着色氧化锆陶瓷的细胞毒性评价   总被引:7,自引:0,他引:7  
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.  相似文献   

15.
颌骨动静脉畸形的栓塞治疗   总被引:9,自引:0,他引:9  
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。  相似文献   

16.
舌前腺囊肿的治疗总结   总被引:4,自引:0,他引:4  
目的:比较2种手术方法治疗舌前腺囊肿的临床效果,为舌前腺囊肿选择合理的手术方法提供依据。方法:41例舌前腺囊肿患者,均采用手术治疗,随机为两分组,A组19例采用常规小黏液腺囊肿摘除术,B组22例采用患侧舌前腺及囊肿一并摘除的术式。术后随访6个月。结果:A组7例复发,B组1例复发。结论:对于治疗舌前腺囊肿,采用舌前腺及囊肿一并摘除的术式效果确切。  相似文献   

17.
牙冠轴面突度的变化对牙周组织健康的影响   总被引:26,自引:0,他引:26  
目的 研究不同程度增加牙冠轴面突度对牙周龈沟液量 (GCF)、龈沟液中天冬氨酸转氨酶 (GCF AST)、碱性磷酸酶 (GCF ALP)水平及软垢堆积水平的影响。方法 将牙冠颊面分别增加0 2mm、0 5mm和 0 8mm ,于 1、4和 8周时测量龈沟液量 ,检测GCF AST、GCF ALP水平 ,记录软垢堆积水平。结果 牙冠轴面突度增加 0 2mm ,各指标没有明显变化 ;增加 0 5mm ,GCF AST水平明显增加 ;增加 0 8mm ,GCF AST、GCF ALP水平增加显著。结论 牙冠轴面突度增加不利牙周健康 ,增加越大 ,牙周健康受到的损害越大  相似文献   

18.
钴铬合金表面粗糙度与细菌黏附   总被引:8,自引:4,他引:8  
目的:了解临床用软质钴铬合金表面粗糙度与细菌黏附的关系。方法:用Talysurf/S5-CD型表面形貌仪测定六组软质钴铬合金试片表面粗糙度。采用体外黏附试验,了解变形链球菌在软质钴铬合金表面的黏附量受表面粗糙度影响的状况。结果:随着研磨和抛光程序的进行,钴铬合金表面粗糙度逐渐减低,其表面的细菌黏附量也不断减少。其中橡皮轮组和抛光膏组之间的表面粗糙度均值和细菌黏附量无显性差异,其余各组间表面粗糙度均值和细菌黏附量均有显性差异。结论:为减少菌斑附着,制作钴铬合金冠修复体后要重视磨光。  相似文献   

19.
Abstract –  The management and immediate treatment of an avulsed permanent tooth will determine the long-term survival of the tooth. The aim of this study was to evaluate the knowledge of oral health professionals on the new guidelines for emergency treatment of avulsed teeth. A 12-item questionnaire was distributed among general dentists, specialists, dental hygienists and dental assistants attending Continuing Education courses at the School of Dentistry, University of Southern California, between 2003 and 2004. This study reports only on the general practitioners who comprised 83% of the participants. The results revealed an uneven pattern of knowledge among them regarding the emergency management of an avulsed tooth. Statistically significant associations were related to the participants' previous dental trauma education and their age. In conclusion, there is a need to improve the knowledge of general dentists in the current guidelines for emergency treatment of avulsed teeth.  相似文献   

20.
[摘要] 目的 建立自体牙移植术的标准化大鼠动物模型,并分析其优缺点。方法 选取5周龄SD大鼠,全麻下先后拔除左上第三磨牙(供牙)和左上第二磨牙(患牙)。预备左上第二磨牙牙槽窝后将供牙放入其中试植,调整方向和咬合后进行树脂粘接固定。术后进行口内愈合情况、影像学及组织学检查。结果 大鼠可以接受自体牙移植手术操作。术后8周口内移植牙固定良好,术区软组织无红肿。组织HE染色可见移植牙牙根和牙槽骨初步愈合,CT显示有少量成骨。该模型具有实验周期较短、成本较低、可重复性较好、以及可以接受多种类型的检查和检测的优点。其缺点包括:个体偏小,实验操作空间小,精细化程度要求较高,以及有些操作不能彻底进行或无法完成。结论 大鼠可以用于自体牙移植术标准动物模型。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号