不同根管预备器械对弯曲根管预备效果的影响

目的:研究不同根管预备器械对弯曲根管预备效果的影响。方法:96例牙髓炎或根尖牙周炎患者作为研究对象,共148颗患牙,按照抽签法,分为观察A组、观察B组和对照组,各32例。观察A组Protaper机,观察B组Mtwo机,对照组不锈钢K锉,比较根管预备时间、弯曲度、疼痛反应、根管锥度、流畅度及充填效果。结果:观察A组、观察B组预备时间显著少于对照组（P<0.05）。观察A组、B组比较无显著差异（P>0.05）。预备后3组根管弯曲度均显著降低（P<0.05）。3组组间比较无显著差异（P>0.05）。观察A组、B组疼痛反应显著优于对照组（P<0.05）;观察A组、观察B组前磨牙、后磨牙的锥度和流畅度显著优于对照组（P<0.05）。观察A组（90.63%）、B组（88.89%）适充充填显著优于对照组（80.00%）（P<0.05）。结论:镍钛预备器械的弯曲根管预备快速,能够保持根管形态,提高充填效果。     

Mtwo机用镍钛锉根管预备的临床效果观察

目的探讨Mtwo机用镍钛锉预备根管的临床效果。方法选取拟行根管治疗的患牙80颗,随机分为试验组和对照组,每组40颗,试验组采用Mtwo机用镍钛锉及改良逐步后退法进行根管预备,对照组采用手用不锈钢K锉和逐步后退法进行根管预备,2组均采用侧向加压法充填根管。比较2组的根管预备时间、根管预备术后疼痛反应和根管充填质量。结果试验组根管预备时间平均为（5.81±0.95）min/根,对照组平均为（13.45±1.08）min/根,试验组明显短于对照组,差异有统计学意义（t=17.15,P〈0.05）;试验组根管预备术后疼痛发生率明显低于对照组,且差异有统计学意义（χ2=4.45,P〈0.05）;试验组根管适充率96.6%,对照组根管适充率85.2%,2组差异有统计学意义（χ2=5.79,P〈0.05）。结论Mtwo机用镍钛锉预备根管快速有效,根管成形、根管充填效果好,并发症少,值得临床推广。     

Mtwo机用镍钛和不锈钢锉进行根管再治疗的比较研究

目的比较Mtwo机将镍钛和不锈钢锉进行根管再治疗临床应用,寻找快速、彻底、疗效良好的根管再治疗方法。方法选择2012年1月—2013年1月我科194例患者的102颗前牙和98颗后牙分为A1组（Mtwo前牙组,51颗）、A2组（Mtwo后牙组,49颗）、B1（不锈钢锉前牙组,51颗）、B2组（不锈钢锉后牙组,49颗）。比较预备时间、术后疼痛的发生率和根充质量。结果 A1预备时间明显短于B1,A2明显短于B2（P〈0.05）;A2组术后疼痛的发生率低于B2组（P〈0.05）;A1、A2组恰填率分别高于B1、B2组（P〈0.05）。结论在临床根管再治疗中使用Mtwo机用镍钛锉比不锈钢锉能减少术中疼痛,节省用时,提高了根充效果。     

Increased apical enlargement contributes to excessive dentin removal in curved root canals: a stepwise microcomputed tomography study

Introduction

To determine whether increased apical enlargement would result in a complete preparation of curved canals and to progressively assess shaping quality using multiple microcomputed tomography (MCT) scans.

Methods

Ninety root canals with a curvature of 25° to 50° were selected. Five MCT scans, 1 preoperative and 4 postoperative, were acquired from each canal. Canal preparation was performed up to size 50 using 3 techniques, nickel-titanium (NiTi) hand files, Mtwo (VDW, Munich, Germany), and ProTaper (Maillefer, Ballaigue, Switzerland), by experienced operators in a dental mannequin so as to simulate the clinical conditions. At a level of 1 mm short of the working length, 2 parameters were evaluated in each of the 4 postoperative acquisitions: the percentage of the prepared outline and the amount of dentin removed (the prepared area).

Results

Statistically, there was no significant difference between the 3 systems used regarding the prepared outline. The maximum prepared outline was achieved by the use of NiTi hand files (63%; confidence interval [CI], 54%–73%), whereas Mtwo and ProTaper amounted to 58% (CI, 50%–66%) and 60% (CI, 51%–70%), respectively. In contrast, the dentin area removed by ProTaper was significantly higher than that of Mtwo and NiTi hand files.

Conclusions

Increased apical enlargement of curved canals did not result in a complete apical preparation, whereas it did lead to the unnecessary removal of dentin.     

不同镍钛系统结合触控启动技术预备模拟弯曲根管的成形效果研究

目的评价HyFlex CM(HF)、TFA、Vortex Blue(VB)和Mtwo共4种镍钛系统结合触控启动(TCA)技术和传统技术(TT)预备模拟弯曲根管的成形效果。方法将96个模拟弯曲根管按照预备器械HF、TFA、VB、Mtwo采用随机数字表法分为4个大组(每组24个),每个大组再按照预备技术(TT或TCA)采用随机数字表法分为2个亚组(每组12个)。各组采用对应镍钛系统及技术预备根管。体视显微镜拍照记录预备前及预备后根管图像。AutoCAD、Adobe Photoshop CS5及Image J软件对预备前、后根管图像进行处理,测量距根尖每隔1 mm处的根管内外侧壁预备量,共测量11个位点,按照距根尖孔距离依次编号为D0~D10,计算各位点根管偏移量。采用两独立样本t检验分析比较各镍钛系统两种预备技术的根管偏移情况,采用单因素方差分析(One-Way ANOVA)比较同一预备技术下4种镍钛系统根管偏移情况,并采用Bonferroni法进行两两比较。结果与TT法相比,采用TCA法显著减小了HF在D0~D2位点(t_D0=2.701,P_D0=0.013;t_D1=3.497,P_D1=0.002;t_D2=2.731,P_D2=0.012),TFA在D2、D5和D6位点(t_D2=2.303,P_D2=0.031;t_D5=4.500,P_D5<0.001;t_D6=2.102,P_D6=0.047),VB在D6、D7和D10位点(t_D6=3.562,P_D6=0.002;t_D7=3.589,PD7=0.002;t_D10=3.004,P_D10=0.007)和Mtwo在D4~D6、D10位点(t_D4=4.668,P_D4<0.001;t_D5=5.645,P_D5<0.001;t_D6=3.627,P_D6=0.001;t_D10=5.778,P_D10<0.001)的根管偏移。对4种镍钛系统成形能力进行比较,不同预备技术下Mtwo在D3~D8位点的根管偏移量均显著大于其他3种镍钛系统(P<0.05);TT法中,VB在D6、D7位点的根管偏移量较HF和TFA大(P<0.05);TCA法中,VB在D4~D6位点的根管偏移量较HF和TFA大(P<0.05);TFA和HF组仅在TT法中的D1位点差异有统计学意义(P<0.05),其余位点差异均无统计学意义(P>0.05)。结论HF、TFA、VB和Mtwo结合TCA法预备弯曲根管具有良好的成形效果。     

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目的评价Mtwo机用镍钛器械用于乳磨牙根管治疗的临床效果。方法选择2013年1—12月南京大学医学院附属口腔医院儿童口腔科门诊就诊的103名4~8岁患儿,应用两种不同预备方法和器械对160颗乳磨牙行根管治疗。其中80颗诊断为急、慢性牙髓炎（P组）,80颗诊断为急、慢性根尖周炎（A组）,P、A每组再随机分为试验组（E组）和对照组（C组）,每组40颗,试验组用Mtwo机用镍钛器械预备根管,对照组用GG钻和不锈钢K锉以改良步退法预备根管。根据操作时间、约诊间痛发生率评价临床效果。结果 PE组与PC组根管预备平均时间分别为（308.5±60.4）和（492.0±48.5）s（P〈0.05）;约诊间痛发生率分别为5.0%和2.5%（P〉0.05）。AE组与AC组根管预备平均时间分别为（379.8±61.3）和（593.8±79.7）s（P〈0.05）;约诊间痛发生率分别为7.5%和20.0%（P〉0.05）。结论 Mtwo机用镍钛根管预备器械能够提高乳磨牙根管治疗的效率和效果。     

Vimentin as antigenic target in autoimmunity: A comprehensive review

Vimentin is a protein of intermediate filament family, which is expressed in all mesenchymal cells. Vimentin plays a key role in the physiology of the cell, cellular interactions and the functioning of the immune system. Post-translationally modified and native forms of vimentin are involved in the pathogenesis of inflammation and many autoimmune diseases: rheumatoid arthritis, sarcoidosis, systemic lupus erythematosus, antiphospholipid syndrome, Crohn's disease, ankylosing spondyloarthritis and idiopathic pulmonary fibrosis. Modifications of the protein lead to the formation of antigenic epitopes and, as a result, to the synthesis of antibodies. Citrullinated, carbamylated and acetylated forms of vimentin participate in the pathogenesis of RA, and antibodies against them serve as diagnostic and prognostic markers of the disease. Epitopes of native vimentin are antigenic in the group of HLA-DRB1*0301 positive patients with sarcoidosis. In addition, vimentin takes part in pathogenesis of tubulointerstitial inflammation and glomerulonephritis in lupus. In antiphospholipid syndrome interactions of vimentin and cardiolipin on the surface of apoptotic cells lead to the formation of an immunogenic complex. Antibodies against vimentin/cardiolipin complex are involved in the mechanism of thrombogenesis and serve to identify patients seronegative for antibodies to cardiolipin and ß2glycoprotein-I with the clinical features. Post-translationally modified form of the protein is citrullinated and MMP-degraded vimentin, which was found in serum of patients with Crohn's disease and ankylosing spondyloarthritis.     

Influence of a brushing working motion on the fatigue life of NiTi rotary instruments

AIM: To evaluate the cyclic fatigue resistance of Mtwo NiTi rotary instruments when used with a brushing or no-brushing action in oval root canals. METHODOLOGY: Cyclic fatigue testing of instruments was performed in tapered artificial canals with a 5 mm radius of curvature and an angle of curvature of 60 degrees. Twenty Mtwo instruments for each size were selected and divided into two groups: group A = 10 instruments used with a no-brushing motion (control group); group B = 10 instruments used with a brushing-milling action. Each Mtwo instrument was used for cleaning and shaping 10 oval root canals. In all 80 instruments were rotated until fracture occurred and the number of cycles to failure (NCF) recorded. Data were analysed by one-way ANOVA, Tukey HSD test and independent sample t-test to determine any statistical difference; the significance was determined at the 95% confidence level. RESULTS: No statistically significant reduction of NCF between instruments used with a no-brushing motion (group A) and instruments used with a brushing motion (group B) were apparent except for size 25, 0.06 taper. Mtwo size 10, 0.04 taper, size 15, 0.05 taper, size 20, 0.06 taper, size 25, 0.06 taper instruments had a decrease in life span of 1%, 0.5%, 8% and 19%, respectively. CONCLUSIONS: Fatigue life of instruments of larger size could be reduced by using them with a lateral brushing or pressing movement. However, each file was successfully operated without intracanal failure, demonstrating that Mtwo rotary instruments can be used safely in a brushing action in simulated clinical conditions up to 10 times in oval canals.