氮化钛镀膜对镍钛锉抗循环疲劳折断性能影响体外研究

目的　探讨磁控溅射氮化钛（TiN）镀膜对镍钛锉抗循环疲劳折断性能的影响,为临床应用提供依据。方法　选取20号和30号的KV4型机用镍钛锉（均为0.04锥度、25 mm长）各40支。将20号锉随机分为A1组和B1组,30号锉随机分为A2组和B2组,每组均为20支。A1组和A2组镍钛器械表面进行TiN镀膜处理（统称为镀膜组）,B1组和B2组镍钛器械表面不做任何处理（统称为未镀膜组）。实验前扫描电镜（scanning electron microscopes,SEM）观察各组镍钛器械表面形貌。将各组镍钛锉置于铜质弯曲根管模型中进行循环疲劳实验,记录每支锉的断裂时间,并结合其转速计算出该锉断裂时旋转的总圈数（NCF）,同时测量其尖端断裂长度。实验后SEM观察各组镍钛器械断面形貌。结果　（1）镀膜组镍钛器械循环疲劳实验中NCF明显大于未镀膜组,差异有统计学意义（P < 0.05）;各组镍钛锉尖端断裂长度差异无统计学意义（P > 0.05）。（2）实验前在低倍及高倍SEM下观察各组镍钛器械表面形貌,发现镀膜组较未镀膜组表面光滑,未见明显加工切割痕迹;实验后发现,除主要疲劳裂纹起源区外,未镀膜组镍钛器械表面的其他位置裂纹相对较多。结论　KV4型机用镍钛锉采用磁控溅射技术进行TiN镀膜后,其抗循环疲劳折断性能显著提高。     

镀膜对镍钛器械抗腐蚀性影响临床研究

目的    探讨镍钛根管器械表面镀膜后是否能提高镍钛根管器械的抗腐蚀性,从而提高其使用寿命。方法       共选用8套Mtwo镍钛器械（每套型号为10号,0.04锥度;15号,0.05锥度;20号,0.06锥度;25号,0.06锥度）,随机分为4组（A1、A2、B1、B2）,每组2套器械,共8只。A1、A2组不做任何处理,B1、B2组进行镀膜。A1、B1组采用5.25%NaOCl作为根管预备过程中的冲洗液;A2、B2组用2.5%NaOCl作为根管预备过程中的冲洗液。通过多弧离子镀膜机将TiZrNO作为阴极电弧蒸发靶原,在B1、B2组Mtwo镍钛器械表面制备一层均匀的0.4 μm厚的膜层。选取2014年8月至2015年8月于中国医科大学附属口腔医院门诊就诊患者拔除的单根牙共80颗,均根尖发育完好、15号K锉到达根尖口且有摩擦感,截去牙冠,留取根尖至釉牙骨质界13 ~ 15 mm。每套器械分别进行根管预备,每次预备1个根管,每换一支锉用冲洗液冲洗根管,预备后放入超声荡洗机内荡洗,封袋高温高压消毒。每套器械预备10个根管。扫描电镜下观察镀膜器械和未镀膜器械,保留图片。最后将每只镍钛器械进行电化学实验,通过恒电位仪获得极化曲线。结果    扫描电镜结果,镀膜镍钛合金根管器械表面性状较未镀膜器械高,电化学测试镀膜镍钛合金根管器械腐蚀速率较未镀膜镍钛器械显著降低。结论    镀膜技术对镍钛合金根管器械进行表面改性可以改善器械表面性状,提高其耐腐蚀性。     

Mtwo镍钛器械在钙化阻塞根管治疗中的应用

目的:对Mtwo镍钛器械处理钙化阻塞根管的疗效进行评价.方法:选取21例35个用C型先锋锉结合EDTA凝胶疏通治疗失败的钙化阻塞根管,应用10#Mtwo镍钛器械结合EDTA凝胶进行钙化疏通处理,观察根管疏通成功率和根管内并发症发生率.采用SAS 9.4软件包对数据进行统计学分析.结果:成功疏通23个钙化阻塞根管,成功率为65.71％.4个根管(11.43％)发生器械分离,3个根管(8.57％)形成根管台阶.按不同钙化部位分为3组,成功率无显著差异(P＞0.05).结论:Mtwo镍钛器械可提高钙化阻塞根管的治疗成功率.     

即刻桩腔预备对三种根管预备方法预备的直根管根尖封闭性的影响

目的 研究三种不同根管预备方法根管预备、根管充填后即刺桩腔预备对直根管根尖封闭性的影响.方法 离体直单根管上前牙124个,其中120个随机平均分为3组(n=40),A组:不锈钢根管锉常规法;B组:G 型钻根管冠部预处理 不锈钢根管锉常规法;C组:手用Pr01raper镍钛根管锉冠向下法,刺余4个随机平均分为阴性对照组和阳性对照组.所有根管均用侧方加压法充填,即刻手持垂直加压器去除部分充填材料,然后P型钻桩腔预备.用染料渗透法评价各组根尖封闭能力.结果 B组G型钻根管冠部预处理 不锈钢根管锉常规法预备的根管和C组手用ProTaper镍钛根管锉冠向下法预备的根管即刻桩腔预备后,其根尖微渗漏较A组常规法预备的轻(P<0.05).结论 大锥度根管预备,根管充填后即刻桩腔预备的根尖封闭性较好.     

ProTaper手用镍钛锉在根管治疗中的应用研究

目的:观察ProTaper手用镍钛锉预备根管的临床效果。方法:280例根管治疗病例随机分为PT组(镍钛根管锉组)140例,300个根管,采用ProTaper手用镍钛锉和冠根向深入法预备根管,KH组140例,296个根管,采用ISO标准型不锈钢K型锉和H型锉根管针,按标准法预备根管,评估预备后疼痛情况、根充效果及根充后反应。结果:PT组根管适填率(91.87%)与KH组(88.51%)无显著性差异(p>0.05);PT组根管预备后疼痛率(4.29%)明显低于KH组(11.43%)(p<0.05);PT组根充术后疼痛率(2.14%)明显低与KH组(8.57%)(p<0.05)。结论:ProTaper手用镍钛锉技术在根管治疗术中及术后反应少。     

两种K型锉预备弯曲人工根管效果的比较

目的 :比较镍钛K型锉和不锈钢K型锉常规法预备弯曲人工根管的切削能力和成形能力。方法 :分别用两种K型锉预备弯曲人工根管 ,电子分析天平称量标本的失重量 ,光学显微镜下观察根管形态变化。结果 :不锈钢K型锉切削能力较强 (P <0 .0 1) ,所有标本未发现根尖拉开、肘部形成和穿孔 ,预备后根尖孔直径镍钛K锉组明显小于不锈钢K锉组 (P <0 .0 0 1)。结论 :镍钛K型锉能保持弯曲根管良好的根管形态 ,而且试尖效果好 ,推荐临床使用     

ProTaper机动镍钛锉在乳牙根管预备中的应用

目的:比较ProTaper机动镍钛锉与手用不锈钢锉在乳牙根管预备中的效果.方法:选择42名4～7岁的儿童50个患有牙髓炎、根尖周炎的下颌第一乳磨牙.随机分成2组,分别用ProTaper机动镍钛锉(A组)与手用不锈钢锉(B组)进行根管预备,使用注射型根管充填剂(Matapex充填剂)进行根管充填.比较两组病例根管预备的时间,X线片观察两组根管充填效果.结果:A组根管预备的时间明显少于B组,差异有显著性(p＜0.01).根充效果观察,下颌第一乳磨牙近中根的恰填率A组高于B组,差异有显著性(P＜0.01).远中颊舌根恰填率A组与B组差异无显著性(P＞0.05).结论:ProTaper机动镍钛锉进行根管预备及使用注射型乳牙根管充填剂充填根管,能大大提高乳牙根管治疗的效率和效果.     

乳牙机用镍钛锉结合超声荡洗用于乳磨牙根管治疗中的临床效果研究

目的:评价不同锥度乳牙机用镍钛锉结合超声荡洗在乳磨牙根管治疗中的临床效果.方法:纳入51例因急、慢性乳磨牙牙髓炎治疗的患儿,共计60颗患牙,随机分为S组、M组和K组(n=20),S、M组使用不同锥度机用镍钛锉预备根管,并结合超声荡洗根管,K组使用不锈钢K锉预备根管,注射法冲洗根管,根据约诊间痛发生率、根管预备和根管治疗...     

ProTaper手动镍钛锉与ISO标准锉根管预备技术的对比实验研究

目的:比较ProTaper手动镍钛锉与ISO标准手用不锈钢K型锉根管预备技术的效果。方法:将40个含弯曲管的透明塑料模块随机分为两组, 每组20个,A组为ProTaper手动镍钛锉预备组(PT组);B组为手用不锈钢K型锉预备组(SS组)。记录每组根管预备所需的时间,预备后根管形态的变化,以及推出根尖液体和碎屑的量。结果:PT组根管预备所用时间明显小于SS组(P<0. 05);预备后弯曲根管被直化的程度PT组明显小于SS组(P< 0. 05 );预备过程中PT组推出根尖液体和碎屑的量显著少于SS组(P<0. 05)。结论:与传统手用不锈钢锉相比,ProTaper手动镍钛锉在根管预备方面有明显的优越性。     

大锥度根管预备混合法在树脂模拟弯曲根管中预备效率的研究

目的观察手用不锈钢K型锉与ProTaper手用镍钛锉联合应用的大锥度根管预备混合法的预备效率。方法采用树脂模拟根管60例,随机分为2组,大锥度根管预备混合法组(简称C组):手用不锈钢K型锉与ProTaper手用F2镍钛锉联合应用;Protaper手用镍钛锉序列组(简称P组)。比较其器械折断情况、操作时间、所用费用和根管预备效果。结果2组均形成冠方大、根端小的连续大锥形根管;C组无断针情况,P组断针率为10%;根管预备时间C组为平均6.37min,P组为平均11.32min(P<0.05);所用成本P组约为C组的4倍。结论大锥度根管预备混合法(C组)预备根管成形效果好,操作时间短,不易断针,且经济实用。     

Effect of physical vapor deposition on cutting efficiency of nickel-titanium files

The purpose of this study was to investigate possible changes in cutting efficiency of nickel-titanium K-files that had undergone physical vapor deposition coating. Titanium nitride coatings were deposited using different process parameters. A total of 84 nickel-titanium K-files (size 35) were randomly divided into 7 groups of 12 instruments each. Groups A to F (experimental): instruments were coated with titanium nitride using different process parameters regarding substrate temperature, applied voltage, coating thickness, and ion bombardment. Group K (control): samples were not coated with titanium nitride. The cutting efficiency of all instruments was determined in a rotary working motion by means of a computer-driven testing device. Special plastic samples with a cylindrical canal were used, and the maximum penetration depth of the instruments into the lumen was the criterion for cutting efficiency. Instruments of groups A, F, and C achieved significantly greater penetration depths than the uncoated instruments of the control group (p < 0.05). Cutting efficiency of physical vapor deposition-coated nickel-titanium files was increased by up to 26.2% in comparison with uncoated instruments.     

Effect of sterilization on the cutting efficiency of PVD-coated nickel-titanium endodontic instruments

AIM: To investigate alterations in cutting efficiency when conventional and titanium nitride (TiN) coated nickel-titanium (NiTi) K-files were exposed to repeated sterilization using an autoclave. METHODOLOGY: A total of 96 NiTi K-files (size 35) were randomly divided into two groups (A and B) of 48 instruments each. Whilst the instruments of group B were exposed to physical vapour deposition (PVD) creating a coating of a TiN layer, the files of group A were not coated. The instruments of groups A and B were randomly divided into four subgroups of 12 instruments each. A.1/B.1: Instruments were exposed to five cycles of sterilization. A.2/B.2: Instruments were exposed to 10 cycles of sterilization. A.3/B.3: Instruments were immersed in NaOCl for 30 min, rinsed in water, and exposed to five cycles of sterilization. A.C/B.C: Instruments were not sterilized (controls). The cutting efficiency of all files was determined by means of a computer-driven testing device. Special plastic samples with cylindrical canals were used and the maximum penetration depth of the files into the lumen was assessed. RESULTS: The TiN-coated instruments of groups B.1, B.2 and B.3 showed no significant difference in comparison with the penetration depths of the controls (P> 0.05). The uncoated files of groups A.1, A.2 and A.3 displayed significantly lower maximum penetration depths (P< 0.05) when compared to the control files. CONCLUSIONS: Repeated sterilization under autoclave or exposure to sodium hypochlorite (NaOCl) prior to sterilization did not alter the cutting efficiency of PVD-coated NiTi K-files.     

�����Ѷ�Ĥ������ﱿ�ѭ��ƣ���۶�����Ӱ�������о�

??Objective??To test the effect of the cyclic fatigue fracture resistance of Nickel-Titanium??NiTi?? files after the magnetron sputtering TiN coating??and to provide basis for clinical application. Methods??The KV4 rotary NiTi files of type 20 and 30??0.04 tapers??25 mm??were selected??40 of each type. The files of type 20 were randomly divided into group A1 and group B1??and the files of type 30 were randomly divided into group A2 and group B2??each group having 20 files. The group A1 and A2 were collectively called coated group??and group B1 and B2 were collectively called uncoated group. A homogeneous layer of 0.6 μm was deposited on the surface of coated group but uncoated group did not underwent any processing. Scanning electron microscopes??SEM??were used to examine surface morphology of NiTi instruments with and without coating. All files were tested for resistance to cyclic fatigue failure inside copper artificial canal. Record the time to fracture from the start of the test until the moment of file breakage and the length of the fractured tip for each file. The number of cycles to fracture??NCF??was calculated according to the rotating speed and fracture time. SEM was used to observe the sectional morphology of each instrument after test. Results????1??NCF of NiTi instruments with TiN coating was significantly higher than NiTi instruments without TiN coating. The difference was statistically significant??P < 0.05??. There was no statistical significance??P > 0.05??in the length of the fractured tip of each group.??2??The surface morphology of coated group and uncoated group were observed under low and high power SEM before the treatment??and the surface of the coated instruments was more smooth??without obvious cutting marks??than the surface of uncoated instruments. After the cyclic fatigue test??in addition to the main fatigue striations??there were relatively more fatigue lines on the surface of the uncoated instrument than coated instrument. Conclusion??The cycle fatigue resistance of KV4 rotary NiTi endodontic instruments has been improved remarkably after the magnetron sputtering TiN coating.     

The effect of surface treatments of nickel-titanium files on wear and cutting efficiency

OBJECTIVES: This study was designed to verify whether nitridation treatment of the cutting surfaces resulted in surface or subsurface changes that produced an increase in the resistance to wear in nickel titanium (NiTi) endodontic files. STUDY DESIGN: Some experimental samples were exposed to ionic implantation by using 150 keV of nitrogen ions and doses of 1 x 10(17) ions per cm(2). Other samples were exposed to thermal nitridation processes performed for 480 minutes at 500 degrees C temperature. Control samples were not exposed to any process. The chemical composition of the surface layers of each sample was determined by means of x-ray photoelectron spectroscopy. The cutting efficiency was tested on an endotraining bloc. RESULTS: The experimental instruments showed in-depth distributions of chemical composition that were different from those seen in the control group; thermal-nitridated instruments demonstrated a surface ratio of nickel to titanium of 0.5. Implanted samples had a higher N/Ti ratio (1.2); this ratio may be due to the presence of a layer of titanium nitride. Samples in the experimental groups showed an increase in cutting ability as compared with the controls. CONCLUSIONS: Thermal nitridation and nitrogen-ionic implantation treatment of nickel-titanium files produced a higher wear resistance and an increased cutting capacity.     

氮化钛涂层对循环摘戴后套筒冠固位力的影响

目的:研究氮化钛涂层对循环摘戴后圆锥型套筒冠固位力的影响.方法:使用精密数控车床制作标准金属内、外冠试件14 对,随机分成2 组(实验组和对照组),每组7 对,在实验组套筒冠内冠表面和外冠内面沉积2 μm氮化钛(TiN),未镀TiN组为对照组,测定2 组套筒冠经循环摘戴后固位力值.采用SPSS 13.0软件包对实验数据进行成组t检验统计分析.结果:镀TiN组套筒冠初始固位力较未镀膜组小, 2 组固位力随循环次数的增加而降低,未镀膜组固位力下降速度较镀膜组更为显著.镀TiN组套筒冠在循环3 000 次后固位力开始下降,3 000 次前和7 000 次后固位力下降平缓.结论:圆锥型套筒冠内、外冠沉积氮化钛涂层可以降低套筒冠固位力衰减速度,能够保持持久的固位力.     

��Ĥ��������е����ʴ��Ӱ���ٴ��о�

??Objective    To electrochemically evaluate corrosion resistance and longevity of nickel-titanium endodontic instruments after modifided by surface coating. Methods    A total of eight sets of new Mtwo NiTi instruments??size 10??size 15??size 20??size 25 in each set??were randomly divided into four groups??A1??A2 and B1??B2??. The instruments of group B1 and B2 were exposed to multi-arc plating machine to create a coating of a TiZrNO layer??and the files of group A1 and A2 were not coated. Scanning electron microscopes??SEM??were used to examine surface morphology of NiTi instruments with and without coating. Moreover??X-ray energy dispersive spectroscopy analysis??EDX??was performed before and after coating to evaluate the effect on the chemical composition. The following irrigation solutions were used??in group A1 and B1 files 5.25% NaOCl was used. In groups A2 and B2 2.5% NaOCl was used. Files were used to prepare single-rooted extracted human teeth. The procedure was repeated to prepare10 canals. Files were used for a cycle of preparation and sent to autoclave. The instruments were sent for corrosion assessment. Results    Scanning electron microscopes showed that surface morphoology has been improved compared with uncoated NiTi instruments. Electrochemical measurements indicated that coated instruments were significantly higher in corrosion resistance  than uncoated instruments. Conclusion    Corrosion resistance and surface morphology of coated NiTi files are significantly higher than that in uncoated files.     

Shear bond strength of veneering composite resin to titanium nitride coating alloy deposited by radiofrequency sputtering

OBJECTIVE: The success of dental restorations utilizing composite resin over cast alloy has been variable and affected by micro-leakage. The purpose of this study was to investigate the shear bond strength between a composite resin and cast dental alloy coated with a layer of titanium nitride (TiN). METHODS: Cast disk specimens made of Au-Pd-Ag alloy were randomly divided into four groups. The first group was left uncoated as a control while one group was coated with a metal conditioner, and the other two were coated with TiN at either 200 or 500 W with a radiofrequency magnetron sputtering system. Each group was then bonded to one of two types of light-activated composite resin material. Shear bond strengths were tested and compared for each specimen. The bond strength of each group was analyzed by 2-way ANOVA and by post hoc multiple comparison tests (Fisher's PLSD). RESULTS: As the interaction among groups was not significant (p=0.27) by 2-way ANOVA, TiN coated groups were found to have improved shear bond strength compared with non-coated groups without metal conditioner for both resin composite materials by multiple comparison tests. Furthermore, TiN coating is significantly stronger than non-coated groups with metal conditioner for one of the two resin composite materials examined (p<0.01). CONCLUSIONS: The results suggested that metal surface modification by coated TiN represents a technique that may significantly improve the bond between the Au-Pd-Ag alloy and veneering resin composite.     

氮化钛镀膜对纯钛铸件表面耐磨性的影响

目的 研究氮化钛(TiN)镀膜对纯钛铸件表面硬度和耐磨性的影响.方法 应用闭合场非平衡磁控溅射(CFUBMS)方法在纯钛铸件表面制备TiN薄膜,显微硬度仪测量纯钛铸件表面硬度,磨擦磨损试验评估其耐磨性.结果 纯钛铸件表面应用CFUBMS方法制备TiN薄膜后,显微硬度明显增加,磨擦系数和磨损体积明显减小.结论 CFUB...