3种镍钛机动器械预备磨牙弯曲根管成形能力的比较

目的:比较3种机动镍钛预备系统(Mtwo、ProTaper和Hero642)预备磨牙弯曲根管的根尖偏移和根管弯曲度的变化.方法:采用3种镍钛机动预备系统预备磨牙弯曲根管,拍摄数字化X线片记录预备前、后分别将15#初尖锉和主尖锉置于根管中的根管影像.用Schneider法测量比较根管预备前、后弯曲度的变化,并将根管预备前后器械尖端相应位置描记后,在立体显微镜下借助测距装置测量根尖偏移指数(ATI).所有数据均采用SAS 6.12软件包进行统计学分析.结果:Hero642系统发生器械折断2枚.3种机动镍钛预备系统中,Mtwo系统根管预备的时间最短,预备1个根管仅需26.7s,ProTaper系统和Hero642系统分别需要28.12s和78.98s;经统计学分析,Hero642系统与另2组之间有显著差异(P＜0.01).3种镍钛机动器械预备前、后根管弯曲度的改变均有显著意义.Hero642系统的根尖偏移最大,ProTaper系统的根尖偏移最小.3组标本经方差分析,无显著差异(P＞0.05).结论:Mtwo和ProTaper机动镍钛预备系统用于预备后牙弯曲根管,效率高,成形能力强,是较理想的弯曲细小根管的预备器械.     

Bonding properties of universal adhesives to root canals prepared with different rotary instruments

Statement of problem

Preparation of coronal dentin by using a diamond rotary instrument usually results in higher bond strength values than preparation with tungsten carbide burs, but information is lacking about the influence of rotary instruments on root canals before the bonding of fiber posts.

大锥度牙胶尖与两种镍钛机动根管预备锉的匹配性研究

目的评价大锥度牙胶尖与两种机动镍钛根管预备锉的匹配性。方法选择40只离体后牙根管,根据初尖锉的号码和近远中向根管弯曲度分为2组,分别以ProTaper和ProFile两种机动镍钛根管锉完成根管预备,插入大锥度牙胶尖进行试尖,比较两者的匹配性。结果ProTaper F1、F2、F3与0.06锥度/20、253、0号牙胶尖的匹配率分别为80%、88%、92%,均较同锥度大1号的牙胶尖匹配率高,差异有显著性(P<0.01)。ProFile 0.06锥度/30号和40号与0.04锥度同号牙胶尖的匹配率最高,分别为83%和96%,其次是0.06锥度小1号牙胶尖,而与0.06锥度同号牙胶尖匹配率最低,分别为35%和25%,3者间差异有显著性(P<0.01)。结论大锥度镍钛机动器械预备的根管,与主尖锉同号而锥度减小或锥度相同且小1号的大锥度牙胶尖有良好的匹配性。     

两种旋转镍钛器械根管预备效果的临床观察

目的对比评价两种设计特点不同的旋转镍钛器械Hero642和Pro Taper的临床成形效果。方法随机选择需要做根管治疗的磨牙100例，分为两组，分别采用两种旋转镍钛器械Hero642和ProTaper预备根管，采用冠向下预备方法。冷侧压方法充填。评价器械损耗、预备时间及成形效果。结果ProTaper器械折断3支，Hero642折断1支；Hero642组预备时间稍短于ProTaper组，两组均能形成较好的根管流畅度（P〉0．05），但ProTaper预备后根管锥度优于Hero642组（P〈0．05），根尖止点清楚。结论ProTaper用于磨牙根管预备的成形效果优于Hero642。但Hero642具有成本低、安全性好、操作易掌握的优点。     

Cyclic fatigue resistance of newly manufactured rotary nickel titanium instruments used in different rotational directions

The aim of this study was to investigate whether cyclic fatigue resistance is increased for nickel titanium instruments manufactured with improved heating processes in clockwise or counterclockwise continuous rotation. The instruments compared were produced either using the R‐phase heat treatment (K3XF; SybronEndo, Orange, CA, USA) or the M‐wire alloy (ProFile Vortex; DENTSPLY Tulsa Dental Specialties, Tulsa, OK, USA). Tests were performed with a specific cyclic fatigue device that evaluated cycles to failure of rotary instruments in curved artificial canals. Results indicated no significant difference in resistance to cyclic fatigue when rotary nickel titanium instruments are used in clockwise or counterclockwise continuous rotation. In both directions of rotation, size 04‐25 K3XF showed a significant increase (P < 0.05) in the mean number of cycles to failure when compared with size 04‐25 ProFile Vortex.     

3种机用镍钛器械在重度弯曲根管预备中根管成形能力的研究

目的：比较机用镍钛Protaper、K3、iRaCe在重度弯曲根管预备中的根管成形能力。方法：收集新鲜拔除的人恒磨牙60颗,要求其中一个根管的弯曲角度为25°～45°,分为Protaper组、K3组和iRaCe组,每组20颗。每颗牙分别在根管预备前后拍摄标准化的平行投照片,通过影像分析来记录根管弯曲度的变化值和根尖偏移量,同时记录折断的器械和根管预备的时间。结果：实验过程中3个组均无器械折断。K3组、iRaCe组在根管预备后根管弯曲角度的变化小于Protaper组,差异有统计学意义（P〈0．05）,K3组和iRaCe组之间差异也具有统计学意义（P〈0．05）。Protaper组、K3组的根尖偏移量大于iRaCe组,差异有统计学意义（P〈0．05）,Protaper组和K3组之间差异无统计学意义（P〉0．05）。三组在操作时间上的差异无统计学意义（P〉0．05）。结论：iRaCe和K3在重度弯曲根管预备中的根管成形能力较Protaper要好,更适合用于重度弯曲根管预备。     

两种机用镍钛器械预备老年人磨牙根管的临床效果比较

目的：比较两种机用镍钛系统Mtwo和ProTaper在老年人磨牙根管预备中的临床应用效果。方法：选择牙髓炎或根尖周炎老年患者磨牙60颗,分别用Mtwo、ProTaper和不锈钢K锉预备根管,全部患牙均采用侧向加压法充填根管。记录根管预备时间,根据术前术后X线片评价根管预备和充填的效果,回访患者术后反应。结果：Mtwo和ProTaper机用镍钛器械均能较好地保持根管的弯曲度和走向,根管预备的锥度和流畅度好,根管形态无改变,未见根管偏移、根尖阻塞、台阶形成等并发症发生;Mtwo和ProTaper机用镍钛器械的操作时间均比不锈钢K锉组短;使用ProTaper组有2例发生器械分离,Mtwo组未见器械分离。结论：Mtwo和ProTaper机用镍钛器械预备老年人磨牙根管均可获得较好的成形效果,均快速高效且较少有根管内并发症发生。     

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目的    比较3种机用镍钛根管预备器械 ProTaper、Mtwo、K3的根管预备效果。方法    选取2009年9月至2010年9月在中国医科大学口腔医学院口腔外科新鲜拔除的54颗上颌第一磨牙的近中颊根,根据其根管弯曲度分成A组（弯曲度≥20°）和B组（弯曲度< 20°）,每组再随机分成3个亚组（P组、M组、K组）,分别采用镍钛锉ProTaper、Mtwo和K3进行根管预备。预备前后,分别拍摄数字X线片,利用计算机图像分析软件生成预备前根管几何中心线并投影至预备后根管,测定根管偏移量及根管弯曲度的变化并且通过扫描电子显微镜观察其中的21例样本根管预备后碎屑和玷污层的分布及评分。结果    根管弯曲度≥20°时,根管弯曲起始处的根管偏移量及根管弯曲度减小量ProTaper组和Mtwo组均显著小于K3组（P < 0.05）;根管弯曲度<20°时,ProTaper、Mtwo、K3组间根管偏移量及根管弯曲度减小量差异均无统计学意义（P > 0.05）。扫描电镜下,P组、M组、K组3者根管冠1/3处碎屑评分差异无统计学意义（P > 0.05）,而在根中1/3及根尖1/3处评分差异有统计学意义（P < 0.05）,其中K组与P组、M组有显著差别（P < 0.05）,3组各部分玷污层评分差异均无统计学意义（P > 0.05）。结论    ProTaper、Mtwo、K3预备上颌磨牙轻度弯曲根管均具有良好的成形能力,Mtwo预备磨牙中、重度弯曲根管能更好维持原始根管走向;配合NaOCl和EDTA冲洗条件下,ProTaper和Mtwo对根管中下段的清理效果优于K3。     

A comparative SEM investigation of the smear layer following preparation of root canals using nickel titanium rotary and hand instruments

The aim of this study was to compare the efficacy of NiTi flex K-file instruments and rotary FlexMaster and Race instruments (short for reamers with Alternating Cutting Edges) in root canal preparation. A total of 75 single rooted teeth with minimum curvature (< 5 degrees ) were selected and divided into three groups, each containing 25 teeth. Canals were prepared with NiTi flex K-file, FlexMaster and Race instruments using crown down preparation technique, up to size #40. After each instrument, the root canals were flushed with 5 ml of 0.5% NaOCl solution. The amount of debris and smear layer was quantified on the basis of Hulsmann method using a scanning electron microscope. Completely cleaned root canals were not found after instrumentation with any of the three instruments. In general, FlexMaster instruments left significantly less debris and smear layer than Race and NiTi flex K-file instruments (P < 0.05). NiTi flex K-files resulted in significantly more smear layer (P < 0.05) compared to Race and FlexMaster instruments only in the apical third of the canal.     

The shaping effects of three nickel-titanium rotary instruments in simulated S-shaped canals

The purpose of this study was to compare the shaping effects of three nickel-titanium rotary instruments, ProTaper, K3, and RaCe, with emphasis on canal transportation. Simulated canals with an S-shaped curvature in clear resin blocks were prepared with a torque-control, low-speed engine. Canals were prepared using the crown-down technique to the size of #30. Canal aberrations were assessed by comparing the pre- and postinstrumentation images under a stereomicroscope. ProTaper instruments caused greater widening of canals compared to K3 or RaCe. Furthermore, ProTaper files showed a tendency to ledge or zip formation at the end-point of preparation. These canal aberrations may be caused by ProTaper finishing files, which appear to be less flexible than other files of the same tip-size, because of their greater taper-size. These results suggest that nickel-titanium file systems including less tapered, more flexible instruments, like K3 and RaCe should be used in the apical preparation of canals with a complicated curvature.     

Efficacy of three rotary NiTi instruments in removing gutta-percha from root canals

Aim To investigate the ability of three rotary nickel–titanium instruments and hand instrumentation to remove gutta‐percha and sealer. Methodology Sixty freshly extracted human single‐rooted teeth, each with one root canal, were instrumented with K‐files and filled using cold lateral compaction of gutta‐percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer. The teeth were randomly divided into four groups of 15 specimens each. Removal of gutta‐percha was performed with the following devices and techniques: ProTaper, R‐Endo, Mtwo and Hedström files. The specimens were rendered transparent and the area of remaining filling material on the root canal wall was measured using a computer image analysis program. Statistical analysis was accomplished by Kruskal–Wallis and Mann–Whitney U‐tests with Bonferroni correction for the analysis of residual root filling material and working time. Results The ProTaper group had less filling material inside the root canals than the other groups, but a significant difference was found between only the ProTaper and Mtwo groups (P < 0.05). The retreatment time for Mtwo and ProTaper was significantly shorter compared with R‐Endo and manual instrumentation with Hedström files (P < 0.001). R‐Endo was significantly faster than manual instrumentation (P < 0.001). Conclusions Under the experimental conditions, ProTaper left significantly less gutta‐percha and sealer than Mtwo instruments. Complete removal of materials did not occur with any of the instrument systems investigated.     

Cyclic fatigue of endodontic nickel titanium rotary instruments: static and dynamic tests

Endodontic instruments upon rotation are subjected to both tensile and compressive stress in curved canals. This stress is localized at the point of curvature. The purpose of this study was to evaluate the cyclic fatigue of 0.04 ProFile nickel titanium rotary instruments operating at different rotational speeds and varied distances of pecking motion in metal blocks that simulated curved canals. A total of 150 ProFile instruments were made to rotate freely in sloped metal blocks at speeds of 200, 300, or 400 rpm by a contra-angle handpiece mounted on an Instron machine. The electric motor and Instron machine were activated until the instruments were broken in two different modes, static and dynamic pecking-motion. The fractured surfaces of separated instruments were examined under a scanning electron microscope. All data obtained were analyzed by a stepwise multiple regression method using a 95% confidence interval. The results demonstrated that the time to failure significantly decreased as the angles of curvature or the rotational speeds increased. However, as pecking distances increased, the time to failure increased. This is because a longer pecking distance gives the instrument a longer time interval before it once again passes through the highest stress area. Microscopic evaluation indicated that ductile fracture was the major cyclic failure mode. To prevent breakage of a NiTi rotary instrument, appropriate rotational speeds and continuous pecking motion in the root canals are recommended.     

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目的    对比研究3种旋转镍钛器械ProFile、ProTaper和Mtwo在弯曲根管预备中的应用。方法    选择2008年2月至2010年2月在沈阳市口腔医院牙体牙髓病科就诊的69例有弯曲根管的牙髓炎或根尖周炎患者的72颗患牙,随机分为4组,分别采用ProFile、ProTaper、Mtwo和不锈钢K锉预备根管,侧方加压法充填。评价根管预备和充填的效果。结果    3种旋转镍钛器械均能较好地维持根管的弯曲度及走向,根管的锥度及流畅度佳,无根管偏移、台阶形成等并发症;术后疼痛少且程度轻;ProTaper和Mtwo的操作时间比ProFile短。结论    机用镍钛器械ProFile、ProTaper和Mtwo预备弯曲根管成形效果好,ProTaper和Mtwo比ProFile更快速高效;临床操作须注意预防器械折断。     

Effective rotary nickel titanium file use: mastering the right touch

Strategies for creating efficiency and safety in the clinical use of rotary nickel titanium instruments are presented with an emphasis on using the correct tactile touch.     

三种机用镍钛锉预备弯曲根管的中心定位能力比较研究

目的　评价M3-Pro 2018、M3-L铂金版及ProTaper universal三种机用镍钛锉预备弯曲根管的中心定位能力。方法　收集2018年10月至2019年3月在常州市第一人民医院口腔科拔除的上颌第一磨牙,筛选出30个近中颊根管弯曲度为20 ~ 40°的近中颊根,随机分成3组,分别为M3-Pro组、M3-L组和ProTaper组,每组10个样本,分别使用M3-Pro 2018机用镍钛锉、M3-L铂金版单支锉系统及ProTaper universal机用镍钛锉预备根管。各样本在处理前后均使用CBCT扫描并利用软件mimics17.0测算距根尖5 mm范围内每毫米处的根管偏移量及轴中心率。结果　距根尖1 mm区域,M3-Pro组、M3-L组和ProTaper组的根管偏移量均值分别为0.06、0.16和0.22 mm,轴中心率均值分别为0.86、0.71和0.49,3组间差异均有统计学意义（F值分别为3.404和3.499,均P < 0.05）。距根尖3 mm区域,M3-Pro组、M3-L组和ProTaper组的根管偏移量均值分别为0.13、0.19和0.26 mm,轴中心率均值分别为0.63、0.51和0.32,3组间差异均有统计学意义（F值分别为7.567和3.996,均P < 0.05）。进一步两两比较发现,距根尖1 mm和3 mm处M3-Pro组与ProTaper组的根管偏移量及轴中心率的差异有统计学意义（P < 0.05）;距根尖3 mm处M3-L组与ProTaper组的根管偏移量差异有统计学意义（P < 0.05）,而两组的轴中心率差异无统计学意义（P > 0.05）。其余观测面上的根管偏移量和轴中心率在3组之间的差异均无统计学意义（均P > 0.05）。结论 M3-Pro 2018机用镍钛锉在弯曲根管的根尖区预备中能更好地顺应根管形状,减小根管偏移量,中心定位能力优于其他两种镍钛锉。     

Pathfile和Reciproc联合应用于预备弯曲根管的临床评价

目的：评价联合使用Pathfile和Reciproc预备弯曲根管的临床效果。方法：选择2012年12月—2013年1月期间就诊需进行根管治疗的88颗患牙273个根管,随机分为3组。A组联合使用Pathfile和Reciproc镍钛锉进行根管预备,B组联合使用Pathfile和ProTaper进行根管预备,C组单独使用ProTaper进行根管预备。3组均采用连续波热牙胶充填。记录每个单根管的预备时间,器械分离数、术后疼痛例数,X线评价根管预备效果。采用SPSS 17.0 软件包对数据进行χ²检验。结果：A组预备时间短,无器械分离,无根管偏移,无台阶形成,能维持根管的弯曲度和走向,预备后疼痛率少,充填效果好。与B组和C组相比,均有显著差异(P<0.01)。结论：Pathfile和Reciproc联合应用于弯曲根管预备快速、安全、成形效果好,并发症发生率低,值得临床推广。     

ProTaper机用镍钛锉预备弯曲根管后的损伤评估

目的评估ProTaper机用镍钛锉在预备弯曲根管后的损伤,以指导临床安全使用。方法选择13套新的ProTaper机用镍钛锉预备下颌第一磨牙近中颊根的弯曲根管,A组6套用于预备中度弯曲根管,B组6套用于预备重度弯曲根管,另外1套作为对照组。每预备1个根管后,在立体显微镜下观察并记录镍钛锉出现磨耗、缺损和分离的情况。选取预备5、10、20个根管后,而且在立体显微镜下检测完好的S1、F1两根锉,在扫描电镜下观察其螺纹表面状况。结果A组ProTaper机用镍钛锉在使用至12个根管后逐渐出现异常;B组在使用至7个根管后逐渐出现异常。在两个实验组中,立体显微镜下未发现磨耗、缺损或分离的锉,在扫描电镜下也可见表面有微裂;随着预备根管数的增多,锉尖微裂增多,先加深后变平;切割刃的微裂逐渐加深延长,使用20次后微裂越过切割刃。结论预备重度弯曲根管较中度弯曲根管易造成ProTaper机用镍钛锉的损伤。使用ProTaper机用镍钛锉预备中度弯曲根管时不宜超过12次,预备重度弯曲根管时不宜超过7次。应用立体显微镜检查有助于发现磨耗及缺损,可以预防临床使用中镍钛锉的突然分离。