Comparison of defects in ProFile and ProTaper systems after clinical use

The purpose of this study was to compare the incidence and mode of instrument separation of the two nickel-titanium (NiTi) rotary systems that were used according to a predefined schedule of clinical use by the same group of operators. A total of 166 ProFile and 325 ProTaper instruments, discarded from this endodontic clinic over 17 months, was analyzed. The incidences of instrument separation were 7% for ProFile and 14% for ProTaper (p < 0.05). The proportion of unwinding defects was 5% in ProFile and 0.3% in ProTaper instruments (p < 0.01). Flexural fatigue was implicated in the majority of separations in both groups. The results of this study indicated that while ProTaper was more likely to separate without warning, ProFile tended to exhibit unwinding of flutes more frequently.     

HyFlex、S3、K3XF以及ProTaper在树脂模拟根管中成形能力的比较研究

目的 通过树脂模拟根管比较HyFlex、S3、K3XF以及ProTaper的成形能力.方法 40个单弯树脂模拟根管随机分为4组,分别使用HyFlex、S3、K3XF以及ProTaper预备根管,数码相机采集预备前后根管的形态,采用图片处理软件Photoshop CS5将其重叠,通过分析软件AutoCAD 2010计算10个观测点的根管树脂去除量并计算中心定位能力,采用SPSS 17.0对数据进行单因素方差分析.结果 HyFlex无器械分离,其他3种器械各发生1例.在距根尖2、3 mm处HyFlex的中心定位能力最好(P<0.05),在4~6 mm处则是K3XF最好(P<0.05).结论 4种器械预备后的树脂根管都保持着较好的根管形态,没有明显的偏移、台阶出现.HyFlex在根尖段的成形能力最好,K3XF则在根管中段更有优势.     

Root canal preparation with the NiTi systems K3, Mtwo and ProTaper

The aim of this paper was to examine the result of rotary root canal preparation with the nickel-titanium (NiTi) systems K3, ProTaper and Mtwo. One hundred and fifty curved artificial root canals and 60 mesial canals of human mandibular molars were selected. In the group of curved artificial canals, all canals were prepared to size 35/0.04 taper with the three systems. In the group of human mandibular molars, the teeth with mature root canals were radiographed with silver points inserted in bucco-lingual and in mesio-distal positions. In the artificial root group, one K3 instrument separated. Mtwo (20%) showed significantly (P = 0.003) less zips than K3 (46.9%) or ProTaper (50%). There were no significant differences in ledge and elbow formation. K3 and Mtwo had the lowest percentage of canal transportation. There was no significant difference regarding the preparation length or the condition of the apical foramina following the preparation. Canals prepared with K3 (26.5%) were significantly (P < 0.001) less tapered than ProTaper (62%) and Mtwo (82%). In the human mandibular molar group, one Mtwo and one ProTaper instrument separated. No significant differences were found in the preparation length, transportation or taper. The three systems tested, K3, Mtwo and ProTaper, achieved good preparation results.     

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。     

A comparison of the canal centering ability of ProFile, K3, and RaCe Nickel Titanium rotary systems

The purpose of this investigation was to compare the ability of three Nickel Titanium (NiTi) rotary systems (ProFile, K3, and RaCe) to centralize instrumentation relative to the original canal location and to determine the distance of transportation of these canals. Sixty mesial root canals mandibular molars with curvature ranging from 15 to 40 degrees were selected. The canals were divided randomly into three groups of 20 canals each. The roots were sectioned horizontally at 3 mm, 5 mm, and 8 mm from the root apex. Teeth were reassembled and instrumented according to the manufacturer's guidelines, with all groups being prepared to size 30 (0.06) taper master apical file. The cross-sections were digitally scanned before and after preparation, and image analysis software was used to assess the centering ability and the extent and direction of transportation. The three groups were statistically compared with analysis of variance and Tukey's HSD test. The results indicated that all three rotary NiTi systems used in this study were able to preserve dentin structure. The RaCe system significantly showed most transportation (p<0.05). The ProFile system was found to be the best for all variables measured in this study.     

An in vitro comparison of the rake angles between K3 and ProFile endodontic file systems

The purpose of this study was to compare rake angles of the ProFile and K3 file systems. Twenty-five 40/0.06 taper files were obtained for each system. Five files from the same manufacturer were placed perpendicularly into a vial of Epoxicure Resin and left to set for 24 h. The set-ups were removed from the vials and each were sectioned 5 mm from the tip of the files and polished. A photomicrograph was taken of each file with 100x magnification. Five sets of ProFile and five sets of K3 files were processed in this manner. Images were captured digitally, and rake angles of each file were measured. Multivariate ANOVA found a significant difference (p < 0.001) among the three negative rake angles of the ProFile system compared with the K3 system.     

Flexibility of K3 and ProTaper universal instruments

This study used a mechanical test to evaluate the flexibility of instruments from the K3 (conicity 0.04) and the ProTaper Universal systems when they were new and after 5 uses in simulated canals. Five sets of instruments of each system were tested: K3 (15, 20, 25, 30, 35, 40 and 45) and ProTaper Universal (S1, S2, F1, F2, F3, F4 and F5). Each set of instruments was used to prepare a simulated canal and the same set of instruments was used 5 times (50 canals). The number of each subgroup represented the number of uses: 0 (control), 1, 3 and 5 uses. Before and after each use, the instruments were submitted to a mechanical flexibility test performed in a Versat 502 universal testing machine. Interactions between the instrument and the number of uses were analyzed by ANOVA and Tukey's test at a 5% level of significance. Instruments from both systems presented lower flexibility after the third use compared to the flexibility obtained after uses 0 and 1 (p<0.05), and maintained the same flexibility after the fifth use. The flexibility of instruments from the K3 system decreased with the increase of diameter, irrespective of the number of uses. Among the instruments from the ProTaper Universal system, the shaping files presented greater flexibility than the finishing files. F2 and F3 were the least flexible instruments, and F4 and F5 presented flexibility values similar to those of F1.     

机用PathFile联合ProTaper镍钛器械治疗磨牙重度弯曲根管的临床研究

目的：探讨机用PathFile联合ProTaper镍钛器械治疗重度弯曲根管的临床疗效。方法：选择2012年10月-2015年10月期间就诊需进行根管治疗的112颗磨牙,共计331个根管,其中134个重度弯曲根管（弯曲度≥25°）。随机分为A,B两组,A组先用PathFile进行冠部预扩大后,再用ProTaper进行根管预备;B组单独使用Pro-Taper预备根管。比较2组患牙治疗后根管预备时间、根尖偏移率、器械折断率及恰填率的差异。结果：A组的根管预备时间较B组稍长,差异具有统计学意义（P＜0.05）;A组根尖偏移率及器械折断率较B组低,恰填率较B组高,差异均具有统计学意义（P＜0.05）。结论：机用PathFile联合ProTaper镍钛器械在预备重度弯曲根管时,能较好的保持根管的原有形态,且充填效果好。     

Shaping ability of ProFile and K3 rotary Ni-Ti instruments when used in a variable tip sequence in simulated curved root canals

AIM: To compare the shaping ability of ProFile and K3 rotary Ni-Ti instruments when used in a variable tip sequence in simulated curved root canals with different curvature and radius. METHODOLOGY: ProFile or K3.06 taper instruments were used to prepare simulated canals of 20 degrees curvature and 5 mm radius (n = 10) and 30 degrees curvature and 3 mm radius canals (n = 10) in resin blocks. All canals were prepared to an apical size 40 at 0.5 mm from the canal terminus using a variable tip crown-down sequence. Pre- and postinstrumentation digital images were recorded, and an assessment of the canal shape was determined using a computer image analysis program. The material removal from the inner and outer wall of the canal was measured at 28 measuring points, beginning 0.5 mm from the end-point of the canal and the data compared using the Mann-Whitney U-test. RESULTS: In 20 degrees and 30 degrees canals both instruments significantly removed more (P < 0.05) material on the outer wall than the inner wall in the apical half of the canal. For ProFile files there was no significant difference in the amount of material removed on the outer canal wall between the 20 degrees and 30 degrees canals. However, in the K3 groups significantly more (P < 0.05) outer canal wall was removed in the apical area in 20 degrees canals. When comparing both instruments the results showed that in 20 degrees canals K3 instruments removed more outer and inner canal wall than ProFile instruments (P < 0.05) but that there was no significant difference (P > 0.05) between the instruments in 30 degrees canals. CONCLUSION: Within the limitation of this study, both rotary nickel-titanium instruments prepared a well-shaped root canal with minimal canal transportation.     

Comparative analysis of torsional and bending stresses in two mathematical models of nickel-titanium rotary instruments: ProTaper versus ProFile

During root canal instrumentation, nickel-titanium rotary instruments are subjected to continual stresses inside the canal due to its anatomy and the hardness of the dentin they must cut. They must therefore be both stress-resistant and elastic. This study aimed to compare the mechanical behavior of two nickel-titanium rotary instruments (ProTaper and ProFile) by applying the finite element analysis method to produce a numerical evaluation. The nonlinear mechanical behavior of the alloy was taken into account during the study. The distribution of stresses due to torsional and bending moments was compared in the two experimental models. The ProFile model was found to be more elastic than the ProTaper model. Under equal loads, the ProTaper model showed lower and better distributed stresses than the ProFile model.     

Cyclic Fatigue Resistance of XP-Endo Shaper,K3XF,and ProTaper Gold Nickel-titanium Instruments

Introduction

The aim of this study was to compare the cyclic fatigue resistance of the ProTaper Gold (PTG; Dentsply Maillefer, Ballaigues, Switzerland), K3XF (SybronEndo, Orange, CA), and XP-endo Shaper (FKG Dentaire, La Chaux-de-Fond, Switzerland) nickel-titanium rotary instruments at intracanal temperatures.

Rotary Ni-Ti profile systems for preparing curved canals in resin blocks: influence of operator on instrument breakage

AIM: The aim of this study was to determine the incidence of fracture of ProFile 0.4 and 0.6 taper Series 29 nickel-titanium instruments with respect to operator experience. METHODOLOGY: A total of 125 simulated root canals in resin blocks with the same geometrical shape in terms of angle and radius of curvature and coronal and apical orifice diameter were used. Five operators prepared all the specimens using an identical step-down instrument sequence, each one preparing 25 canals. The operators included two endodontists and three general practitioners. Statistical data concerning the incidence of instrument failure was compiled using Statlab and Fisher's partial least square difference analysis of variance. RESULTS: A total of 21 (16.8%) instruments fractured, all had 0.04 tapers. Nine size 25 instruments failed, 9 size 20 instruments failed and 3 size 15. During the study, the Binary Tree analysis of instrument failure revealed two operator populations belonging to two different study periods. The first period, which represented the first 13 root canal preparations, was called the 'learning period', and the second period, which represented the next 12 sample preparations, was called the 'application period'. A greater number of instruments failed during the first period than during the second. In the 'learning period', both groups of operators learned the same way. In the 'application period', two groups could be distinguished; the first group consisted of a general practitioner who produced worse results, and the second group consisted of the other four operators. CONCLUSIONS: The results indicate the necessity of mastering this rotary canal preparation technique, and the importance of improving competence through learning and experience.     

机用镍钛器械预备清理根管效果的定量分析

目的:比较机用镍钛根管预备器械ProFile与手动器械对弯曲根管的清理效果.方法:3组弯曲根管分别进行ProFile、手动不锈钢RT锉、NiTiflex锉预备.立体显微镜下观察根管纵截面并采用图象分析软件Scion Image 1.62定量分析根管碎屑分布比例与根尖栓塞的形成.结果:ProFile组碎屑指数小于其他两组;碎屑栓发生率各组无显著性差异,但与根管弯曲部位相关.结论:ProFile器械采用冠根向深入法对弯曲根管碎屑的清理优于手动器械,但仍应注意弯曲位于根尖1/3段者易发生根尖阻塞.