镍钛根管器械表面性状的观察

目的:通过体视显微镜和扫描电子显微镜观察几种国产和进口镍钛根管器械的表面性状,为其临床的使用提供参考资料。方法:取全新6种国产和进口镍钛根管器械各一套,清洁后分别在体视显微镜和扫面电子显微镜下进行表面性状的观察。结果:进口镍钛根管器械的外形规整,其尖端采取了钝化处理,刃部锋利,螺纹均匀致密,螺纹之间的凹槽较深。国产根管器械的外形相对不规整,其尖端没有采取钝化处理,刃部圆钝,螺距较大,螺纹之间的凹槽较浅。结论:本研究中进口镍钛根管器械在尖端设计、刃部和体部外形上比国产镍钛根管器械规范、合理。     

影响镍钛合金根管器械表面性状的因素

镍钛合金根管器械在折断之前,其表面性状或多或少都会发生一些改变,而影响镍钛器械表面性状的因素有很多.本文就影响镍钛根管器械表面性状的因素以及改善表面性状的一些措施作一简要综述.     

镍钛机动根管预备器械对根管弯曲度的影响

目的：评价3种镍钛机动预备系统保持弯曲率的能力及其工作效率,方法：离体下颌磨牙近中弯曲根管64个,随机分为4组：Flexofile,LightSpeed,ProFile,Qantec SC.分别预备到主尖锉30号和40号,对各组器械预备前后的根管弯曲度和预备时间进行测量。结果：Flexofile组的根管弯曲度减少最明显,在颊舌向与另外3组镍钛器械间的差异均有非常显著意义（P＜0．01）,在主尖锉为30号的镍钛组,预备前后的根管弯曲度无统计学差异（P＞0．05）,ProFile和Quantec SC预备都显著缩短操作时间,与Flexofile组间的差异有显著意义（P＜0．01）。结论：镍钛机动预备器械能很好地保持根管的原有弯曲度,节省预备时间。     

镍钛机动器械预备弯曲根管的研究进展

弯曲根管的预备是根管治疗中的难点，镍钛合金制制成的根管机动预备器械具有良好的成形能力和抗腐蚀性能，在弯曲根管预备中。京能取得满意的成形和清理效果。临床应用前景良好，但是，镍钛器械的折断仍为亟待解决的问题。     

ProFile镍钛合金根管预备器械研究进展

ＰｒｏＦｉｌｅ镍钛合金根管预备器械有三种不同类别,均为大锥度器械,采用冠根向预备技术,以１５０～３５０ｒ／ｍｉｎ的转速进行根管预备。该器械柔韧性佳,切削能力强,尤其在预备变曲根管时安全、快捷,根管成形理想。     

镍钛机用器械根管预备

自1988年Johnsen发明Profile后,镍钛机用器械逐渐成为根管预备的主要器械,医师可以借助机动器械对根管进行安全处理,引发了根管治疗的技术革命。1.镍钛机用器械概述目前国内使用的系统主要有:Profile(Dentsply)、ProTaper(Dentsply)、Hero642(Micro-Mega)、Hero Shaper(Micro-Mega)、K3(Sybronendo)、Flexmaster(VDW)、Race(FKG)、GT(Dentsply)和Light Speed(LigthSpeedUSA)等,这些系统有一定的相似性,也有各自的特点。镍钛机用系统的共同特点:①镍钛金属材料的成分基本雷同;②大锥度的设计;③均为螺旋设计,器械在根管中能方…     

Lightspeed根管预备器械

根管预备是根管治疗成败的关键。通常在直根管系统预备时容易达到满意的效果,但在预备弯曲根管时,不仅碎屑难以清除,且易产生根管并发症,影响疗效。为此,器械的设计在不断改进,应用技术亦得到发展。其中最具突破性的是Ｗｉｌｄｅｙ[1]1989年介绍的ＣＭ(ＣａｎａｌＭａｓｔｅｒ)器械,与常规根管锉的设计不同,它的特点是:①杆部无锥度。②刃部长2.5～4.0ｍｍ。③尖端较短,由切割功能变为导向功能。与常规器械相比,该器械在预备弯曲根管时可减少根管迁移(ｔｒａｎｓｐｏｒｔａｔｉｏｎ)(1991)[2]。但由于原ＣＭ器械由不锈钢(ｓｔａｉｎｌｅｓｓ…     

ProFile镍钛合金根管预备器械研究进展

ProFile镍钛合金根管预备器械有三种不同类别,均为大锥度器械,采用冠根向预备技术,以150～350r/min的转速进行根管预备。该器械柔韧性佳,切削能力强,尤其在预备弯曲根管时安全、快捷,根管成形理想。     

镍钛器械对椭圆形根管预备效果的影响

椭圆形根管具有特殊的解剖学形态,使用镍钛器械预备根管时在追求良好的成形能力同时,也会有不良的影响。目前几种常用的镍钛器械中,既有较高牙本质切削效率的优势也有形成牙本质微裂的风险;虽然镍钛器械代代更新,但是目前研究发现无论哪种器械对于椭圆形根管预备均具有一定的缺陷。本文将从镍钛系统对椭圆形根管的成形能力,包括切削能力、保持原有根管形态的能力以及不良影响如推出根尖孔碎屑量、形成牙本质微裂的影响两个大方面进行综述,为选择合适的镍钛器械预备椭圆形根管提供依据。     

镍钛手用器械预备弯曲根管的临床评价

目的　观察镍钛手用器械预备弯曲根管的临床效果 ,寻找治疗弯曲根管的有效方法。方法　将临床根管治疗的弯曲根管随机分为 2组 ,对照组用不锈钢 (stainlesssteel,SS)K锉行根管预备 ,试验组用镍钛合金 (nickel titanium ,NT)手用器械行根管预备 ,预备方法均采用逐步后退法。结果　两组器械对弯曲根管的预备经过各项指标检测 ,均有显著性差异。结论　NT手用器械在弯曲根管的预备方面较SS K锉有明显的优越性     

Comparative Study of Different Novel Nickel-Titanium Rotary Systems for Root Canal Preparation in Severely Curved Root Canals

Introduction

We compared the effects of 6 different rotary systems on transportation, canal curvature, centering ratio, surface area, and volumetric changes of curved mesial root canals of mandibular molar via cone-beam computed tomographic (CBCT) imaging.

Methods

Mesiobuccal root canals of 120 mandibular first molars with an angle of curvature ranging from 20°–40° were divided into 6 groups of 20 canals. Based on CBCT images taken before instrumentation, the groups were balanced with respect to the angle and radius of canal curvature. Root canals were shaped with the following systems with an apical size of 25: OneShape (OS) (MicroMega, Besancon, France), ProTaper Universal (PU) F2 (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next X2 (Dentsply Maillefer), Reciproc (R) R25 (VDW, Munich, Germany), Twisted File Adaptive (TFA) SM2 (SybronEndo, Orange, CA), and WaveOne primary (Dentsply Tulsa Dental Specialties, Tulsa, OK). After root canal preparation, changes were assessed with CBCT imaging. The significance level was set at P = .05.

Results

The R system removed a significantly higher amount of dentin than the OS, PU, and TFA systems (P < .05). There was no significant difference among the 6 groups in transportation, canal curvature, changes of surface area, and centering ratio after instrumentation.

Conclusions

The 6 different file systems straightened root canal curvature similarly and produced similar canal transportation in the preparation of mesial canals of mandibular molars. R instrumentation exhibited superior performance compared with the OS, TFA, and PU systems with respect to volumetric change.     

Root Canal Preparation and Enlargement Using Thermally Treated Nickel-Titanium Rotary Systems in Curved Canals

IntroductionThe purpose of this study was to evaluate root canal preparation and apical enlargement of curved canals using rotary heat-treated and heat/surface-treated systems by micro–computed tomographic imaging.MethodsCurved mesial root canals (n = 48) of mandibular molars (20°–40°) were prepared using ProDesign Logic (PDL; Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) 25/.01 and 25/.06 or HyFlex EDM (HFEDM) 10/.05, HyFlex CM 20/.04, and HFEDM 25/.08. Apical enlargement was performed using PDL 40/.05 or HFEDM 40/.04. Scanning (9 μm) was performed before and after preparation and after apical enlargement using micro–computed tomographic imaging. Volume, percentage of volume increase, debris, untouched root canal surface, and centering ability were analyzed. Statistical analysis was performed using Mann-Whitney, Wilcoxon, and unpaired t tests (α = .05).ResultsHFEDM promoted a higher volume increase of the root canals than PDL after preparation and after apical enlargement (P < .05). The apical enlargement promoted a significant decrease in debris and untouched surface in both groups (P < .05). The percentage of debris and untouched surface were similar between HFEDM and PDL after preparation and after apical enlargement (P > .05). Both systems promoted centered canals (P > .05).ConclusionsHFEDM instruments promoted greater volume of the root canal than PDL. However, the cleaning ability of the instruments was similar. The apical increase up to size 40 with both instruments provided less debris and untouched surfaces and allowed centralization of the curved root canals.     

FlexMaster镍钛器械根管预备效果研究

目的：评价机用FlexMaster镍钛器械根管预备效果。方法：选择因正畸或牙周病拔除的新鲜单根管离体牙60颗,根管弯曲度20°-40°,随机分成3组（FM组、H组、PF组）,分别使用机用FlexMaster、Hero642、ProFile镍钛器械,冠根向技术预备根管,通过数字牙片、扫描电镜和软件分析方法,观察比较根管拉直程度、安全性能、根尖偏移指数、牙本质小管开口数目、根管壁碎屑、玷污层等情况。结果：3组器械均能较好的维持弯曲根管的原有解剖形态,根管拉直程度差异无显著性。各组的根尖偏移指数均小于0.2 mm,视为无偏移发生,差异无显著性。牙本质小管开口数目在根管中1/3段FM组及H组牙多于PF组,在根管尖1/3段FM组多于H组及PF组,差异有显著性（P〈0.05）。根管中1/3段和根管尖1/3段,FM组和H组根管壁碎屑较PF组少,差异有显著性（P〈0.05）。各组根管壁总体较为清洁,绝大多数牙本质小管开放,仅有少量玷污层,玷污层记分差异无显著性。结论：FlexMaster镍钛系统安全、有效,能较好维持根管的初始形态,具有较好的根管成形能力和清理效果,值得临床推广使用。     

Influence of Operator's Experience on Root Canal Shaping Ability with a Rotary Nickel-Titanium Single-File Reciprocating Motion System

Introduction

The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system.

Methods

Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions.

Results

Significant differences (P < .05) were found in the apical transport of the first root canal curvature, with a larger percentage of increase of the root canal occurring in the novice group than in the expert one, as well as in the canal deviation at the beginning of the curvatures, whereas no significant results were obtained in the growth rate of the canal area. There was difference in the time of instrumentation, with 3.76 minutes observed in the novice group, as opposed to 2.05 minutes in the expert group.

Conclusions

The use of the single-file reciprocating motion system Reciproc is not seen to be influenced by the operator's experience regarding the increase of the canal area. Previous training and the need to acquire experience are important in the use of this system, in spite of its apparent simplicity.     

Evaluation of a New Nickel-Titanium System to Create the Glide Path in Root Canal Preparation of Curved Canals

Introduction

Nickel-titanium rotary instruments recently have been introduced with the purpose of creating an initial glide path. The purpose of this study was to compare the maintenance of canal anatomy, the occurrence of apical transportation, and the working time observed using mechanised instrumentation with the new G-File rotary system (Micro-Mega, Besançon Cedex, France) with those observed using instrumentation with the PathFile system (Dentsply Maillefer, Ballaigues, Switzerland) and manual instrumentation with K-type files (Micro-Mega) to create a glide path in curved root canals.

Methods

The mesial canals of 45 mandibular molars (with curvature angles between 25° and 35°) were selected. The specimens were randomly divided into 3 groups with 15 canals each, and canal preparations were performed by an endodontist using #12-17 G-File rotary instruments (group GF), #13-16-19 PathFile rotary instruments (group PF), and #10-15-20 K-type stainless steel manual files (group M). A digital double radiographic technique was used to determine apical transportation and the change in the angle of curvature. The working time was also calculated.

Results

No statistically significant differences in the angle of canal curvature and apical transportation were found between the groups. However, concerning the working time, specimens from the group who underwent canal preparation using #12-17 G-File rotary instruments achieved significantly lower mean values when compared with the other 2 groups, whereas the group who underwent canal preparation using the #10-15-20 K-type stainless steel manual files had the highest values.

Conclusions

The G-File rotary instruments, the PathFile system, and the manual instruments did not have any influence on the occurrence of apical transportation nor did they produce a change in the angle of canal curvature. The G-File instruments seemed to be the most rapid system in creating a safe glide path.     

声波根管预备器械杀菌作用的研究

目的：研究声波器械根管内的杀菌作用.方法：将36个根管预备至80^#,根尖孔封闭和2/3牙根包埋的离体前牙,随机分为蒸馏水组和次氯酸钠组.将已知细菌浓度的变形链球菌（Ingbritt）、粘性放线菌（ATCC 19246）和金黄色葡萄球菌（ATCC 25923）菌液分别置于根管内,分组加入蒸馏水和次氯酸钠.用声波器械处理根管1、2、3、4、5和6 min,取样、细菌培养后,计数,行前后细菌存活率比较,通过x2检验进行统计学分析,比较不同成分冲洗液对杀菌作用的影响.结果：蒸馏水组,随声波器械处理时间的增加,细菌存活率逐渐下降.到6 min后,仍可见细菌菌落的生长.次氯酸钠组,细菌的存活率明显降低.至3 min后,琼脂平板已未见细菌菌落的生长.1 min和2min,次氯酸钠组和蒸馏水组的细菌存活率比较有显著性差异（P＜0.05）.结论：声波器械本身的杀菌作用是有限的,结合低浓度次氯酸钠溶液作为冲洗剂可以获得良好的根管杀菌效果.     

Effects of Root Canal Curvature and Mechanical Properties of Nickel-Titanium Files on Torque Generation

IntroductionThis study aimed to compare the torque generated by 4 different files in root canals with 4 different curvature angles.MethodsFour brands of nickel-titanium (NiTi) endodontic files were selected: WaveOne Primary (Dentsply Sirona, Ballaigues, Switzerland), WaveOne Gold Primary (Dentsply Sirona), ProTaper Universal F2 (Dentsply Sirona), and ProTaper Next X2 (Dentsply Sirona). A tempered steel block containing artificial canals with 4 different canal curvatures (15°, 25°, 35°, and 45°) was constructed. Each file was used according to the manufacturer’s instructions in the dynamic model, with an added 15 axial up-and-down movements of 4 mm at the end of the canal. The generated torque was recorded, and the total and maximum torque values were measured. Two-way analysis of variance and the Duncan post hoc comparison test were performed at a significance level of 95%.ResultsA significant correlation between the curvature angle and the type of file system was observed (P < .05). As the degree of canal curvature increased, the generated total and maximum torque increased. At 15° and 25°, the NiTi files with reciprocating motion generated a higher total and maximum torque than files with continuous rotation. ProTaper Universal of conventional NiTi alloy showed the steepest increase in the generated total and maximum torque with the increasing curvature angle. The ProTaper Next file had the lowest torque values at the higher canal angles of 35° and 45° (P < .05).ConclusionsDespite the study limitations, it can be concluded that root canal curvature, design, and heat treatment of NiTi files and file kinematics affect the generated torque during instrumentation.     

机用ProTaper锉临床折断情况分析

目的探讨机用ProTaper锉临床折断的特点,以期为临床治疗提供指导。方法收集患者500例,磨牙850颗,共2 750个根管,使用机用ProTaper锉进行根管预备。治疗后登记ProTaper锉使用次数,进行分类,根管显微镜下观察锉变形及折断情况并进行统计学分析。结果在预备40个根管前均无ProTaper锉发生变形与折断,折断与变形多发生于预备50个根管后,锉的折断率随预备根管数目的增多而增高,差异有统计学意义（P〈0.05）;4只常用ProTaper锉折断情况：F1最易折断,共6支,F2次之,S2最不易折断,差异有统计学意义（P〈0.05）。6支ProTaper锉中S1最易发生肉眼可见的变形,F3次之,SX、S2、F1、F2显微镜下也不易发现明显的变形,差异有统计学意义（P〈0.05）。结论机用ProTaper锉临床使用时多折断于根尖区3 mm,变形多发生在S1和F3,术前应仔细检查器械是否有肉眼可见的缺陷,并严格记录预备的根管数目。