弯曲根管用镍钛器械预备后根管偏移的研究

目的:研究3种镍钛根管预备器械预备后牙弯曲根管产生根管偏移的情况。方法:选择48个弯曲度>25°的下颌第一、二磨牙近中根包埋于Branmante模型中,分别用机动Hero642、Profile和手用ProTaper、不锈钢K锉进行根管预备。拍摄根管预备前后根尖、根中段横截面的影像,测定根管偏移的量、方向和轴中心率。结果:Hero642和Profile在根尖段和根中段根管的偏移显著小于不锈钢K锉,手用ProTaper仅在根尖段小于不锈钢K锉; 3种镍钛器械的轴中心率均低于不锈钢K锉,而镍钛器械组间无显著性差异;镍钛器械和不锈钢器械在根尖段根管中心偏向近中侧,而在根中段不锈钢K锉和手用ProTaper根管中心多数偏向远中侧,与Hero642和Profile有显著性差异。结论:Hero642、Profile和ProTaper在预备弯曲根管时有较小的偏移及良好的中心定位作用,尤其是Hero642和Profile对根尖和根中段成形能力较佳。     

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.     

两种镍钛机动器械预备根管的疗效评价

目的探讨机动镍钛器械Hero 642和ProTaper对根管的成形能力及其临床应用方法。方法60例60颗患牙分为2组,每组患牙30颗,分别采用机动镍钛器械Hero 642和ProTaper预备根管,侧向加压充填技术充填根管,根据治疗前后的X线片评价根管预备和充填效果,记录根管预备后器械折断、变形情况,1周后复诊,评价患牙的疼痛发生率。结果两组患牙根管预备后的根管不良形态率、根充适充率、术后疼痛率均无显著性差异。Hero 642操作简单,在根管预备过程中体现出较低的器械折断率。结论Hero 642和Protaper镍钛机动系统具有良好的根管成形作用,临床上可根据其各自的特点选用。     

机用镍钛器械预备弯曲根管的临床应用

目的　研究机用镍钛器械ProFile、ProTaper和Hero 642在弯曲根管预备中的临床应用。方法　选取有弯曲 根管的牙髓炎或根尖周炎患牙80颗,分为A、B、C、D 4组,分别用ProFile、ProTaper、Hero 642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。根据X线片评价根管预备和充填的效果。结果　3种机用镍钛器械均能很 好地维持根管的弯曲度和走向,根管的锥度和流畅度佳,无根管偏移、根尖阻塞、台阶形成等并发症发生;术后疼痛 发生少且程度轻;ProTaper的操作时间比ProFile和Hero 642短;有2例镍钛器械折断。结论　机用镍钛器械ProFile、 ProTaper和Hero 642预备弯曲根管成形效果好,极少有根管内并发症发生,ProTaper比ProFile和Hero 642更快速高 效;临床操作中须注意预防器械折断。     

镍钛器械对中重度弯曲根管成形能力的临床研究

目的:探讨机动镍钛器械Hero642结合ProTaper SX对弯曲根管的成形能力及其临床应用方法。方法:选取有中、重度弯曲根管的牙髓炎及根尖周炎患牙42颗,采用机动镍钛器械Hero642结合ProTaper SX预备根管,侧向加压充填技术充填根管,根据治疗前后的X线片评价根管预备和充填效果。结果:所有患牙均无台阶、根管偏移及侧壁穿孔等并发症发生,弯曲根管的弯曲度和走向未改变,术后疼痛发生少,有1例器械折断。结论:Hero642结合ProTaper SX的预备方法对中重度弯曲根管的成形效果好,值得临床推广应用。     

机用镍钛Hero642预备磨牙弯曲根管的临床研究

目的探讨机用镍钛器械Hero642应用于磨牙弯曲根管预备的效果。方法选择根管弯曲的磨牙86颗,先采用小号K锉疏通根管,将根尖部预备至15号后,再以机用镍钛器械Hero642完成根管预备,侧向加压充填根管,根据治疗前后的x线片评价根管预备和充填效果。结果86颗磨牙共有274个根管,264个根管形态良好,无台阶、根尖堵塞、根管偏移及侧壁穿孔等并发症发生。根充恰填256个,8个根管超充,10个根管未能完全扩通,无法到达根尖孔而欠充或做塑化治疗。结论手用锉疏通弯曲根管的根尖段后再以机用镍钛器械Hero642完成根管预备,可获得良好的成形效果且较少产生并发症。     

倒敞法结合2 种机用镍钛锉预备重度弯曲后牙根管的应用研究

目的:评价倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管的疗效.方法: 随机将100 颗患牙髓炎或根尖周炎、最大根管弯曲度≥25°的后牙分为2 组,各50 例.实验组(A组)采用倒敞法,而对照组(B组)不采用倒敞法机械预备.A组以机用开口锉根管中上端敞开后,手用K锉预备根尖,再先用镍钛器械Hero 642,后用ProTaper预备根管;B组则直接应用Hero 642和ProTaper冠向下法预备根管. 2 组均用侧压法充填根管.根据X线片情况,预备时间,器械折断、疼痛等并发症,评价根管预备和充填的疗效,1 年随访率95%.结果:A组倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,锥度、流畅度好,术后疼痛少且程度轻,无器械折断;而B组发生器械折断3 支(P>0.05);充填恰充率、欠充率、流畅度、术后疼痛两者有显著性差异(P<0.05).结论: 倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,成形、根充效果好,并发症少,最大限度发挥了各自优点,是预备重度弯曲后牙根管值得推广应用的有效方法.     

初学者应用两种镍钛机动器械预备树脂弯曲根管的效果比较

目的 比较初学者应用两种机用镍钛器械Protaper和Her0642预备树脂弯曲根管的效果.方法 选取仿制单弯树脂根管32个,15名初学者分别用两种机用镍钛系统Protaper和Her0642进行根管预备,2个仿制单弯树脂根管为阴性对照.分别从推出根尖碎屑量、根尖偏移量及根管弯曲度变化等方面评价两种器械系统的根管预备效果.所有数据均采用SPSS 13.0软件包进行统计学分析.结果 Protaper组预备前后根管弯曲度平均减小6.77°,Hero642组减小5.480°,Protaper组减小根管弯曲度较Hero642组明显.Protaper组成形后的根管宽度均值均大于Hero642组,且根管口、根中1/3成形后的根管宽度差异有统计学意义(P<0.05).此外,根管预备过程中Protaper器械折断3支,Hero642器械折断1支.结论 对于初次使用机用镍钛器械的操作者,尽管Protaper具有良好根管成形的优点,但Hero642系统操作技术简单容易掌握、高效、安全,更适合初学者在临床上使用.     

两种镍钛机动器械预备根管的效果分析

目的　评价使用两种镍钛机动器械预备磨牙根管的临床疗效。方法　选取需行根管治疗的 10 0颗患有牙髓炎及根尖周炎的磨牙 ,分别使用机用镍钛器械Protaper、Hero6 4 2冠向下预备根管 ,两组均使用侧压充填法充填根管。记录根管预备时间及器械折断数量。根据治疗前、中、后的X线片计算弯曲根管的弯曲度变化 ,评价根管预备和充填的效果。结果　Protaper和Hero6 4 2预备根管时间短 ,根管锥度、流畅度好 ,术后疼痛发生少且程度轻。Protaper预备后根管弯曲度平均减小 4 0 2°,Hero6 4 2平均减小 1 72°,二者差异有统计学意义 (P <0 0 0 1)。Protaper器械折断 5支、Hero6 4 2未发生器械折断 (P <0 0 5 )。结论　镍钛机动器械Protaper、Hero6 4 2预备磨牙根管成形、根充效果好。Protaper减小根管弯曲度较Hero6 4 2明显 ,但易折断。Hero6 4 2操作简单 ,不易折断目的　评价使用两种镍钛机动器械预备磨牙根管的临床疗效。方法　选取需行根管治疗的 10 0颗患有牙髓炎及根尖周炎的磨牙 ,分别使用机用镍钛器械Protaper、Hero6 4 2冠向下预备根管 ,两组均使用侧压充填法充填根管。记录根管预备时间及器械折断数量。根据治疗前、中、后的X线片计算弯曲根管的弯曲度变化 ,评价根管预备和充填的效果。结果　Protaper和He     

使用三维重建技术研究不同根管预备器械的预备效果

目的：采用CT扫描结合三维重建技术,评价3种根管预备器械K-file、机用Protaper、机用Hero642的根管预备效果。方法：对离体牙进行CT扫描,建立三维数字模型,对根管预备前、后的横截面面积、根管内容积、根管内表面积及根管偏移情况进行比较分析。结果：在根管预备前后的横截面面积、根管内容积、根管内表面积差值上,Protaper组最大,手用K-file组最小;在根管预备前后根管偏移量方面：手用K-file组最大,机动Hero642组最小。结论：机动Protaper的牙本质切削能力优于机动Hero642;机动镍钛根管预备器械保持原有根管解剖走行的能力优于手用不锈钢器械。     

两种机用镍钛根管预备器械在树脂模拟弯曲根管内的成形能力

目的 利用树脂模拟弯曲根管,研究K3和Hero642两种机用镍钛根管预备器械的成形能力.方法 使用K3和hero642分别预备两组树脂模拟弯曲根管至06锥度25#,运用扫描仪采集根管预备前后图像,Image ProPlus软件测量根管预备后的根管宽度和预备前后的弯曲度,使用SPSS13.0统计软件对预备前后树脂模拟弯曲根管宽度和弯曲度变化进行统计学分析.结果 K3组和Hero642组根管预备前后角度的变化分别为（4.11±0.18）°和（4.05±0.23）°,两者差异无统计学意义（P＞0.05）;两组器械预备后根管宽度的比较在根尖1/3、根中1/3和根管口处都无显著性差异（P＞0.05）.结论 两种机用镍钛根管预备器械均能较好地完成根管预备.     

4种机用镍钛器械预备模拟弯曲根管的效果评价

目的:比较4种机用镍钛器械预备模拟弯曲根管的成形效果。方法:40个单弯(弯曲度38.5°)树脂根管,随机编号分4组(Hero642、Protaper、K3及Mtwo)。按厂家推荐方法预备,记录预备时间,扫描仪获取图像,使用图像分析、测量软件将预备前、后的图像重叠,测量根管内、外侧壁树脂去除量、弯曲度及弯曲半径等的变化。采用SPSS13.0软件包对数据进行单因素方差分析。结果:K3预备速度最慢,Mtwo最快(P<0.05)。在根管弯曲起始点(BC)、根管口(O)和两者中点(HO)处内侧壁以及弯曲最凸点(AC)、HO和O处外侧壁的预备量4组间差异显著,Protaper预备后根管锥度变化最大,Hero642最小(P<0.05)。Protaper在根管弯曲段的中心定位能力最差;越接近根管下份偏移增大。K3与Protaper各1例断针,K3有2例台阶,安全性能、不良形态、根管弯曲角度及半径的改变方面,4种器械无显著差异,但预备后根管工作长度缩短,略有被拉直趋势。结论:Mtwo能快速预备根管;Protaper预备后根管锥度最明显;4种机用镍钛器械均具备良好的切屑力且维持原始根管走向。     

Hero 642对弯曲根管根管成形能力的评价

目的：评价机用镍钛锉Hero 642预备弯曲根管时的根管成形能力。方法：利用自主研制的《牙齿模拟根管辅助分析测量系统》软件,定量检测8个模拟根管在用Hero 642以冠下法预备前后的形态变化,并进行统计学分析。结果：机用镍钛锉Hero 642能够很好地保持根管的原始弯曲度。在预备至0.02锥度25#銼和30#锉时,Hero 642对弯曲根管的各部位切割均衡,根管几何中心线基本不移位。结论：机用镍钛锉Hero 642具有良好的根管成形能力。对于高度弯曲的根管,预备主锉仍可选择0.02锥度30^#锉。     

Curved molar root canal preparations using Hero 642 rotary nickel–titanium instruments

AIM: The Bramante method was used to study how the natural curvature of root canals was modified when using the Hero 642 nickel-titanium rotary system. METHODOLOGY: Twenty-four canals were selected in freshly extracted human mandibular molars. Every root canal had an angle of curvature greater than 20 degrees. Roots were embedded in clear casting resin using a plaster mould. Cross-sectional cuts were made in the apical, middle and coronal thirds of each root. A first group (control) of 12 curved root canals was prepared using stainless steel hand instruments and the step-back technique. A second group of 12 curved root canals was instrumented using the Hero sequence according to the manufacturer's instructions. For each sectioning level, the amount of dentine removed, the change of shape factor and the canal centre displacement were calculated with the aid of a digital image analysis system. The results were subjected to the Mann-Whitney U-test. RESULTS: No significant difference occurred in the amount of dentine removed, change of shape factor or canal centre displacement in the coronal and middle thirds of the curved canals. In the apical third, transportation was significantly higher (P=0.0171) with stainless steel hand instruments than with the Hero system. CONCLUSIONS: The original canal shape was maintained better in the apical third of curved canals when using the Hero system in a crown-down technique when compared to a hand preparation technique with stainless steel instruments.     

Canal preparation with Hero 642 rotary Ni-Ti instruments compared with stainless steel hand K-file assessed using computed tomography

AIM: To compare ex vivo root canal preparation with conventional stainless steel K-files and Hero 642 rotary Ni-Ti instruments. METHODOLOGY: Mesiobuccal canals of 20 maxillary first molars (with angles of curvature between 25 degrees and 35 degrees ) were used. After preparation with Hero 642 rotary instruments and stainless steel K-files, the amount of transportation that occurred was assessed using computed tomography. The teeth were scanned by computed tomography before instrumentation. One millimetre thick slices were prepared from the apical end point to the pulp chamber. The first two sections were 3 mm from the apical end of the root (apical level) and 3 mm below the orifice (coronal level). A further section (mid-root level) was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. Ten teeth were instrumented using Hero 642 rotary instruments and another 10 teeth were instrumented using stainless steel K-files. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross-sectional images taken prior to canal preparation. Amount of transportation and centreing ability was assessed. Student's t-test was used for statistical analysis. RESULTS: Less transportation occurred with Hero 642 rotary instruments than stainless steel K-files at the mid-root and coronal levels (mid-root: P < 0.05 and coronal: P < 0.001). Hero 642 rotary instruments had better centreing ability than K-files at all three levels (apical: P < 0.05, mid-root: P < 0.05 and coronal: P < 0.001). CONCLUSIONS: Hero 642 rotary instruments transported canals less, especially at the middle and coronal thirds of the root canals than stainless steel K-files. Hero 642 instruments had better centreing ability.     

A comparison of Profile, Hero 642, and K3 instrumentation systems in teeth using digital imaging analysis

OBJECTIVE: To evaluate the changes in cross-sectional area morphology of curved canals after instrumentation with Profile((R)), Hero 642((R)), and K3((R)) using digital imaging analysis.Study design Thirty mesial mandibular curved canals were used (25-40 degrees ). The molars were embedded in resin and the roots were sectioned transversely at three levels: apical, middle, and coronal. The canals were randomly distributed into 3 groups for instrumentation using Profile.04 and.06, Hero 642, and K3. The pre- and postinstrumentation sections were digitized and areas corresponding to the canals were measured with image-processing software. RESULTS: Hero eliminated significantly more dentine than K3 and Profile in all 3 sections (P <.01, ANOVA test), with no differences observed between the latter 2 systems (P >.05, Student-Newman-Keuls test). All 3 systems yielded a rounded canal morphology in the coronal, middle, and apical thirds. CONCLUSION: Hero rotary instruments produced more changes in cross-sectional area of the root canal.     

Shaping ability of progressive versus constant taper instruments in simulated root canals

AIM: To compare the shaping ability of progressive versus constant taper shaft designed instruments in simulated root canals. METHODOLOGY: Simulated L- and S-shaped resin canals were prepared by ProTaper (progressive taper) and high elasticity in rotation 642 (Hero 642) (constant taper) instruments (n = 10 canals in each case). The pre- and post-instrumentation images were recorded and assessment of the canal shape was completed with image pro plus 5.0. The width of resin removed was measured at 9 measuring points. Incidence of canal aberrations, instrument fracture, preparation time and change of working length were recorded. In addition, the change of curvature and centring ability were also assessed. The data were analysed statistically using Student's t-test or Fisher's exact-test. RESULTS: In both canal types, Hero 642 instruments prepared canals more rapidly (P < 0.01) and maintained working length significantly more accurately than ProTaper instruments (P < 0.05). In canals prepared with Hero 642 instruments, there was less change in curvature. Instrumentation with ProTaper results in transportation towards the outer aspect of the L-shaped curved canals in the apical part and the inner aspect of the S-shaped canals at the curve. Hero 642 instruments had a better centring ability in the apical part of the canal, but resulted in shapes with a poor taper. CONCLUSIONS: ProTaper and Hero 642 instruments prepared curved canals rapidly, maintained working length well and were relatively safe without creating perforations and danger zones. In both canal types, Hero 642 instruments maintained the original canal curvature better, and had a better centring ability in curved canals because of its constant taper design. The taper prepared by Hero 642 instruments in the coronal part of the canal was generally poor.