机用镍钛锉根管预备的临床应用研究

目的：比较机用镍钛锉与手用K型锉根管预备的临床应用。方法：将牙位相同、诊断相同，全身情况类似的患者按随机配对原则分入甲乙两组，甲组为镍钛锉预备组；乙组为K型锉预备组，每组50例患者。结果：对于单根管牙齿，使用机用镍钛锉进行根管预备，所用时间与传统手用K型锉根管预备相比无显著差异，对于双根管牙及磨牙而言，采用机用镍钛进行根管预备所用时间明显少于使用传统手用K型锉根管预备，根管预备一周内，使用机用镍钛锉根管预备与传统手用K型锉根管预备术后反应无显著差异，结论：传统手用K型锉预备根管相比，机用镍锉具有省时省力的优点。     

Comparison of apical transportation between ProFile and ProTaper NiTi rotary instruments

AIM: To use a newly developed radiographic technique to compare apical transportation and loss of working length (WL) between.06 taper ProFile Series 29 and ProTaper nickel-titanium (NiTi) rotary instruments in vitro. METHODOLOGY: Mesio-buccal canals of 40 extracted mandibular molars were randomly divided into two groups. Group 1 was instrumented with ProFile and group 2 with ProTaper instruments according to the manufacturers' directions. A specially constructed radiographic jig with a Schick digital radiographic system (Schick Technologies Inc., Long Island City, NY, USA) was used to take pre- and postoperative radiographs of the samples at predetermined angulations. Using AutoCAD 2000 (Autodesk Inc., San Rafael, CA, USA), the central axes of initial and final instruments were radiographically superimposed to determine the loss of WL and degree of transportation at D(0), D(1), D(2) and D(4) from the WL. Data were analysed using repeated-measures anova. RESULTS: A statistically significant difference in apical transportation was found at the D(4) level between the two groups (P = 0.05). There was no statistical significance regarding postinstrumentation change in WL between groups. Spearman's Bivariate Correlation analysis indicated no statistically significant relationship between the radius of curvature and transportation. CONCLUSION: The results indicate that both ProTaper and ProFile instruments are comparable to each other in regards to their ability to optimally enlarge root canal with minimal transportation and loss of WL in vitro.     

Comparison of clinical outcomes using a nickel titanium rotary or stainless steel hand file instrumentation technique

The purpose of this study was to evaluate the concept that novice clinicians could perform clinical endodontics better and more efficiently if the stainless steel hand file technique is replaced with a nickel titanium rotary file technique. In phase 1 of the study, every endodontic case performed by 2 groups was evaluated for total treatment time. In phase 2, the mesial roots of mandibular molars were evaluated for radiographic quality of completed obturation. The authors found that when the rotary file technique was substituted for the hand file technique, appointment time for case completion was significantly decreased (P<.001) and overall radiographic quality of mandibular molar mesial root obturation was significantly increased (P=.0009). These results support the hypothesis that novice clinicians can perform endodontic therapy more efficiently when using a nickel titanium rotary file technique. In addition, no differences were noted in the incidence of file fracture when using rotary instruments.     

Variability of the diameter and taper of size #30, 0.04 nickel-titanium rotary files

This investigation examined the variability of tip diameter (D0) and taper measurements among four different brands of #30, 0.04 nickel-titanium (NiTi) rotary files (n=15/brand). With all brands, the mean percent D0 difference from the manufacturer's reported (nominal) diameter (Profile GT, 1.73+/-2.03%; Endo Sequence, 3.38+/-3.91%; K3, 4.56+/-2.36%; Profile, 6.13+/-4.07%) indicated that files tended to be larger than the nominal diameter. A 1-factor ANOVA and Tukey's post hoc test revealed a statistically significant difference (p0.05) of brand on the mean percent difference of the measured taper compared to the nominal taper with the majority of measurements at either 0.039 or 0.040 taper.     

The K3 rotary nickel-titanium file system

The K3 rotary nickel-titanium file system by SybronEndo is a state-of-the-art rotary nickel-titanium endodontic instrumentation method combines excellent cutting characteristics with a robust sense of tactile control and excellent fracture resistance. The K3 has universal applicability across a wide range of clinical indications. Although it is a complete instrumentation system, future possibilities for hybrid instrumentation techniques that combine the best features of K3 with other rotary system hold promise.     

The effect of preflaring on the rates of separation for 0.04 taper nickel titanium rotary instruments

The purpose of this study was to compare the rates of separation of 0.04 taper nickel titanium (NiTi) rotary instruments using two different instrumentation techniques. Twenty sets of 0.04 taper Profile Series 29 rotary instruments, sizes 2 to 6 were used in the mesial (mandibular) or buccal (maxillary) canals of extracted human molars with a 20 to 30 degree root curvature according to the Schneider classification. The rotary instruments were used up to 20 times either with the crown-down technique recommended by the manufacturer or with a combination of preflaring with hand files in a passive step-back technique followed by rotary instrumentation. Statistical analysis of the data showed that the combination technique allowed more uses before separation compared with the crown-down technique recommended by the manufacturer p < 0.0001.     

机用镍钛锉去除根管旧充填物能力的体外研究

目的研究0.04锥度的镍钛锉去除根管旧充填物的能力.方法将30颗单根管前牙分成A、B、C三组,每组10颗.用K型锉行根管颈备、牙胶尖+氧化锌侧压法充填.放置30天后用不同的方法去除根管旧充填物A组为K型锉+氯仿组;B组为镍钛锉+氯仿组;C组为单纯应用镍钛锉组.记录操作时间、氯仿用量.将牙根纵劈,立体镜下观察牙根整体及其不同水平的残留物情况,将结果进行统计学分析.结果对于根管整体的残留物量,C组少于A组,存在显著性差异(P=0.007),其余的实验组间无显著性差异(P＞0.05).对于操作时间,B、C两组均少于A组(P＜0.05),B、C两组间无显著性差异(P＞0.05).B组的氯仿用量少于A组(P＜0.05).结论同K型锉相比,机用镍钛锉去除根管旧充填物更为完善且操作时间显著减少.     

两种后牙根管预备方法的临床效果比较

目的 :评估 2种后牙根管预备方法的临床效果。方法 :采用机用镍钛扩大锉 (ProFile)和手用不锈钢扩大锉 (K file)扩大后牙根管 ,并对 2组病例术后疼痛以及充填情况加以比较。结果 :发现机用镍钛扩大锉扩大后牙根管 ,具有去除根管感染物质彻底 ,根管形态保持良好 ,速度快 ,术后疼痛率较低的优点 ,但易出现断针。而手用不锈钢扩大锉扩大后牙根管速度较慢 ,术后疼痛率略高 ,但不易出现断针 ,操作上容易掌握。结论 :2种后牙根管方法都有优缺点 ,可结合起来使用。     

两种机用镍钛器械根管预备的临床应用研究

目的评价两种设计特点不同的机用镍钛器械Hero642和Mtwo预备磨牙根管的临床效果。方法选取需行根管治疗的60颗患有牙髓炎或根尖周炎的恒磨牙,随机分为两组,分别使用机用镍钛器械Hero642冠向下法预备根管和Mtwo改良逐步后退法预备根管,两组均使用冷侧压法充填根管。根据治疗前后的X线片评价根管预备效果,比较器械损耗、预备时间及术中、术后并发症的发生率。结果两组均能形成较好的根管流畅度,但Mtwo组预备后根管锥度优于Hero642组（P〈0.05）。Hero642组预备时间短于Mtwo组（P〈0.05）。Mtwo组有两例发生器械分离、Hero642组未发生器械分离。结论Mtwo用于磨牙根管预备的成形效果优于Hero642,但Hero642具有省时、成本低且安全性好的优点。     

Torsional properties of new and used rotary K3 NiTi files

The purpose of this study was to compare torque (gcm) and angle of rotation (degrees) at fracture of new and used NiTi K3 .04 rotary instruments. The relation between size of instrument and torque at fracture was also investigated. The torque and angle of rotation at fracture of new and used NiTi K3 .04 rotary instruments sizes 15 to 40 were determined according to ANSI/ADA Specification No. 28. Analysis of variance was used to compare the torque and angle of rotation at fracture among the different sizes of the new instruments and between new and used instruments of the same size (alpha = 0.05). The relationship between torque at fracture and size of instrument was determined with a regression analysis. Torque at fracture of the new instruments increased significantly with the diameter (p < 0.05). The used instruments, sizes 25 to 40, had significantly lower torque at fracture values compared to the new ones (p < 0.05). The used instruments, sizes 20 and 35 had significantly lower angle of rotation at fracture compared to the new ones (p < 0.05). A stronger relationship was found between the size of the file and the torque at fracture for the new instruments (p < 0.0001) compared to the used ones (p < 0.0001). The results of the present study suggested that the torque at fracture values of new instruments increased significantly with the diameter. The results also suggested that repeated use of .04 K3 instruments affected mainly the torque at fracture.     

Comparison of K hand files and ProFiles 0.06/0.04 in simulated curved root canals prepared by students.

OBJECTIVES: The objective of this study was to compare the step-down technique in simulated curved root canals using K hand files (VDW) and ProFiles 0.06/0.04 (Dentsply Maillefer). METHOD AND MATERIALS: A total of 72 canals were blindly prepared by instructed students: 1 block with K files and a second one with ProFiles 0.06/0.04 in connection with the EndoStepper (SET). Postoperative images of the canals were taken, and an independent dentist assessed preparations for amount and position of material removed during preparation. Efficacy of the instruments is described in terms of canal shape, instrument failure, canal blockages, and preparation time. RESULTS: ProFile instrumentation provided well-centered and tapered preparations while maintaining the apical foramen; in contrast, the use of K files resulted in frequent alterations of the root canal. In the apical portion, both techniques showed unprepared areas. The coronal diameter in hand-instrumented canals was more irregular and wider than in those mechanically prepared. There was no separation of a ProFile instrument. Hand instrumentation was faster than mechanical, but the difference was not statistically significant. CONCLUSION: Under the conditions of the study, the ProFile rotary system was simple and safe to use and created better preparations than hand instrumentation.     

二种机用镍钛锉预备老年患者磨牙弯曲根管疗效观察

目的:比较机用镍钛锉Protaper和Hero642预备老年患者磨牙弯曲根管时,保持原根管解剖走向的能力。方法:选择2007.3～2010.3口腔科门诊年龄60-70岁牙髓病初诊病例,按Schneider测量法,选择磨牙弯曲根管(25°-30°)200例,随机分为Protaper组100例,Hero 642组100例,进行根管预备。测量主锉插针牙片和初锉插针牙片的根管弯曲度,确定根管偏移度,评价根管预备和成形效果。结果:Protaper组成功率92%,失败率8%,偏移2.8度。Hero 642组成功率99%,失败率1%,偏移1.6度。二组成功率有显著性差异(P<0.05)。结论:①Hero 642镍钛锉对于老年患者磨牙弯曲根管的成形能力明显优于Protaper镍钛锉。②联合应用二种镍钛锉,先用Hero 642扩通根管,再用Protaper成形根管,可以减少根管偏移,提高根充质量。     

ProFile ProTaper镍钛根管器械与不锈钢K锉预备弯曲根管的比较研究

目的：比较ProFile镍钛机用根管器械，ProTaper镍钛手用根管器械和不锈钢K锉用于弯曲根管预备时的根管拉直和根尖偏移，为ProFile和ProTaper的临床应用提供实验依据。方法：将正畸前减数拔除的30个下颌第一前磨牙随机分为3组，分别用不锈钢K锉、ProTaper镍钛手用根管器械、ProFile镍钛机用根管器械做根管预备，分析评价其根管拉直和根尖偏移情况。结果：不锈钢K锉组的根管拉直、根尖偏移显著大于ProTaper和ProFile预备组。结论：ProFile和ProTaper镍钛根管预备器械与传统的不锈钢器械相比更适合弯曲根管的根管预备。     

不锈钢K锉和镍钛K锉预备弯曲根管效果的比较研究

目的：比较手动不锈钢K锉与手动镍钛K锉预备弯曲根管的能力。方法：选取40个下颌磨牙近中颊侧弯曲根管，随机分为两组，每组20个根管。分别采用手动不锈钢K锉与手动镍钛K锉预备。采用双曝光技术比较两种器械预备弯曲根管后的根管偏移发生率。结果：两组根管偏移发生率存在显著性差异。结论：手动镍钛K锉能较好的维持根管原有形态。     

K锉初步预备和扭矩对机用ProTaper抗折性能的影响

目的探讨K锉初步预备和扭矩对机用ProTaper抗折性能的影响。方法分别计算各组机用ProTaper器械折断或变形前所预备的S型树脂模拟根管的数目。结果A1组（模拟根管未经K锉初步预备）S1预备了13个模拟根管;B1组（模拟根管经K锉初步预备）s1预备了36个模拟根管;A2组（低扭矩组）S2预备了17个模拟根管;B2组（高扭矩组）s2预备了18个模拟根管;A3组（低扭矩组）F1预备了14个模拟根管;B3组（高扭矩组）F1预备了14个模拟根管;A4组（低扭矩组）F2预备了6个模拟根管;B4组（高扭矩组）F2预备了6个模拟根管。结论根管经K锉初步预备可降低机用ProTaper器械折断的发生;扭矩的高低对机用ProTaper器械的抗折性能没有明显影响。