根管偏移对充填材料封闭根管能力的影响

目的：研究弯曲根管预备后的根管偏移对充填材料封闭根管能力的影响。方法：选取73颗下颌单根管前磨牙作为研究对象，其中弯根管牙46颗，直根管牙27颗，A组23颗弯根管牙用Lightspeed器械预备根管，B组23颗弯根管牙，C组17颗直根管牙以及对照组牙用K锉预备根管，预备方法为逐步后退技术，使用双曝光X线技术和Ehrlich法测量根管偏移指数（AT1）的大小，使用侧向加压技术充填所有根管后，用流体传输模型测量每个根管内微渗漏的量，结果：A组中有19％的根管发生根管偏移，B组中有85％的根管发生根管偏移，两组之间AI1的大小有高度显著性差异，当ATI大于0．3nm，时，根管内微渗漏的发生率明显增加，结论：弯曲根管顶备中出现的根管偏移会削弱充填材料封闭根管的效果。     

ProTaper联合Pathfile镍钛锉预备狭窄弯曲根管的临床评价

目的 比较联合使用ProTaper和Pathfile镍钛锉、单独使用ProTaper镍钛锉、单独使用不锈钢K锉预备狭窄弯曲根管的临床效果.方法 因牙髓炎或根尖周炎需根管治疗的93颗患牙,336个根管,平均分为A组、B组和C组,A组联合使用Pathfile和ProTaper镍钛锉,冠向下法进行根管预备;B组单用ProTaper镍钛锉,冠向下法进行根管预备;C组单用预弯的弹性K锉,逐步后退法进行根管预备.比较3组在根管预备时间、器械折断率、恰填率及根尖偏移率方面的差异.结果 A、B、C组的根管预备时间分别为(8.51±2.32) min、(7.08±1.56) min、( 13.76±3.28) min,差异有统计学意义(F=223.796,P＜0.01).A组器械折断率(0.00％)、台阶形成率(0.89％)、根尖偏移率(7.14％)最低,恰填率(92.86％)最高.3组之间器械折断率、恰填率、台阶形成率和根尖偏移率差异均有统计学意义(P＜0.05).结论 Pathfile和ProTaper镍钛锉联合使用可减少狭窄弯曲根管的预备时间,且安全可靠,根管充填效果好.     

不同根管器械预备弯曲根管的实验研究

目的比较手用不锈钢K锉、手用ProTaper锉、机用ProTaper锉在预备中、重度弯曲根管时的成形能力及其对根尖孔形态特征的影响。方法将40个树脂根管模型分为A、B、C、D组，A、B、C组各12个树脂根管模型，其中每组20°根管和30°根管各6个；D组4个树脂根管模型，均为小于5°根管。分别以手用不锈钢K锉、手用ProTaper锉、机用ProTaper锉预备根管，数码相机摄片，运用专业图像分析软件Auto-CAD比较根管偏移及根尖孔形态。结果B组中轴偏移明显高于A组和C组（P<0.05），其中C组与A组在个别根管段有显著差异（P<0.05）。预备后根尖孔B组各项值均显著高于其他各组，B3组根管值显著高于B2组（P<0.05）。相同根管弯曲度下C组值高于A组；不同弯曲度下30°根管值高于20°根管值，但均无显著性差异（P>0.05）。结论两种镍钛器械均产生根管偏移，根管弯曲度是偏移产生的主要原因；与不锈钢器械相比，镍钛器械能较好地保持原根管走向及根尖孔形态。     

根管偏移对充填材料封闭根管能力的影响

目的 :研究弯曲根管预备后的根管偏移对充填材料封闭根管能力的影响。方法 :选取 73颗下颌单根管前磨牙作为研究对象 ,其中弯根管牙 46颗 ,直根管牙 2 7颗。A组 2 3颗弯根管牙用Lightspeed器械预备根管 ,B组 2 3颗弯根管牙、C组 17颗直根管牙以及对照组牙用K锉预备根管 ,预备方法为逐步后退技术。使用双曝光X线技术和Ehrlich法测量根管偏移指数 (ATI)的大小。使用侧向加压技术充填所有根管后 ,用流体传输模型测量每个根管内微渗漏的量。结果 :A组中有 19%的根管发生根管偏移 ,B组中有 85 %的根管发生根管偏移 ,两组之间ATI的大小有高度显著性差异。当ATI大于 0 .3mm时 ,根管内微渗漏的发生率明显增加。结论 :弯曲根管预备中出现的根管偏移会削弱充填材料封闭根管的效果。     

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。     

Pathfile和Protaper联合预备磨牙弯曲根管的临床评价

目的：评价联合使用Pathfile和Protaper预备磨牙弯曲根管的临床效果。方法：选择需进行根管治疗的磨牙102颗,376个根管,随机分为2组。根管预备过程中,A组联合使用Pathfile和Protaper镍钛锉,B组仅使用Protaper镍钛锉。2组均采用连续波热牙胶充填。比较2组在根管预备时间、器械分离率、根尖偏移率、根管恰填率以及预备后疼痛发生率等方面的差异。采用SPSS 16．0对数据进行x2检验。结果：在根管预备时间方面A组与B组差异无统计学意义;A组在器械分离率、根尖偏移率、根管恰填率及预备后疼痛发生率等方面均较B组为优,且差异具有统计学意义（P＜0．05）。结论：Pathfile和Protaper联合使用预备磨牙弯曲根管具有安全、快速、根尖偏移率低、充填效果好、术后疼痛少等特点。     

ProTaper与不锈钢K锉预备弯曲根管的对比研究

目的：对比ProTaper镍钛手用根管器械和不锈钢K锉进行弯曲根管预备时的根尖偏移和根充后密度。方法：将正畸减数拔除的下颌第一前磨牙20个随机分为2组,每组10个。分别用不锈钢K锉、ProTaper镍钛手用根管器械做根管预备,对比分析并评价根尖偏移和根充后密度情况。结果：两组根管偏移发生率和根充密度存在显著性差异。结论：ProTaper镍钛根管预备器械与不锈钢器械相比更适合弯曲根管的预备。     

3种器械预备弯曲根管的比较研究

目的 :比较不锈钢K型锉、镍钛合金K型锉以及镍钛合金X型锉预备弯曲根管的根尖偏移。方法 :将 4 5个 15°～ 35°的弯曲前磨牙根管按弯曲度排序后均匀分成 15个区组 ,每区组 3个根管 ,再随机分配至3个不同器械处理组。根管冠部用GG钻预处理后 ,行常规法预备根管 ,拍摄数字化X线片记录预备至不同锉号时根管器械尖端所在位置。最后 ,将根管预备前后器械尖端相应位置描记后 ,在立体显微镜下测量不同锉号根管预备后的根尖偏移。结果 :3组标本的根尖偏移均随锉号的增大而增大 ,# 35和 # 4 0不锈钢K型锉根管预备所致的根尖偏移与另外两组标本相比有显著性差异 (P <0 .0 5 ) ,另有两个标本根管侧穿 ;两组镍钛合金锉之间的根尖偏移无显著性差异 (P >0 .0 5 )。结论 :对于弯曲根管 ,用镍钛合金锉预备 ,其效果优于不锈钢锉。     

镍钛器械联合应用于磨牙弯曲根管预备的临床效果

目的 比较ProTaper联合镍钛K锉、S3锉、ProTaper锉3组镍钛器械在预备磨牙重度弯曲根管中的临床效果.方法 选取重度弯曲根管的磨牙150颗,随机分为3组(n=50个),分别使用ProTaper联合镍钛K锉(A组)、S3锉(B组)、ProTaper锉(C组)预备根管,侧压法充填根管,比较3组器械的根管成形效果、器械分离情况、术后疼痛反应情况.结果 3组器械预备根管后成形效果良好率分别为82.0％、86.0％、62.0％,A、B组两组器械的根管成形效果均优于C组,差异有统计学意义(P<0.05).B组的器械分离数最少,B组与C组差异有统计学意义(P<0.05).3组的术后疼痛反应发生率为分别6.0％、4.0％和4.0％,差异无统计学意义(P>0.05).结论 在磨牙重度弯曲根管中,ProTaper联合镍钛K锉和S3锉均有良好的临床效果.     

手用ProTaper镍钛器械在老年人根管治疗中的临床应用

目的：比较手用ProTaper镍钛器械与手用K锉在老年人根管治疗中的临床应用研究。方法：老年患者127例,138颗患牙。其中手用ProTaper组65例,72颗患牙为实验组;手用K锉组62例,66颗患牙为对照组。结果：实验组无根管偏移、根尖阻塞、台阶形成及根尖孔敞开等根管内并发症的发生,根管的锥度及流畅度极佳。对照组有5个根管发生根尖阻塞,3个根管在根尖1/3处有台阶形成;有5个中度弯曲的根管和4个重度弯曲的根管有轻度至中度的根尖孔偏移。结论：2种器械根管预备有显著差异,ProTaper镍钛器械根管预备后维持厚根管形态和高充填质量。     

Leakage along apical root fillings in curved root canals. Part I: effects of apical transportation on seal of root fillings

Occurrence of apical transportation (AT) may complicate the root filling procedure and result in a compromised seal. In part I of this study, human mandibular premolars with single, curved (21 to 39 degrees), or straight canals were prepared by Lightspeed or a step-back hand filing technique. An AT index was determined using a double exposure radiographic technique. The prepared canals were obturated using lateral condensation of gutta-percha. Leakage along the apical 3 mm of root filling was measured with a fluid transport model. After hand filing, AT and perforation occurred in 87% of the curved canals. The AT indices were > or = 0.4 mm. After Lightspeed preparation, AT occurred in only 19% of the curved canals. The hand filing/curved group leaked statistically significantly more than the hand filing/straight and Lightspeed/curved groups (p = 0.002). We conclude that occurrence of AT is a factor that negatively influences the apical seal when curved canals are obturated by lateral condensation of gutta-percha.     

Preparation of curved root canals with rotary FlexMaster instruments compared to Lightspeed instruments and NiTi hand files

AIM: To compare the recently introduced rotary FlexMaster instruments with Lightspeed instruments and NiTi hand files in preparing curved root canals. METHODOLOGY: Root canals of extracted molars were shaped with rotary FlexMaster instruments ('FM': n = 45), Lightspeed instruments ('LS': n = 46), and NiTi hand files (n = 45) using the balanced-force technique. The apical preparation size was 40. Root canal instrumentation was carried out in a phantom head under clinical conditions. A re-assembly technique allowed a comparison of the canal outline before and after preparation. Root sections 2.5 mm short of working length were used to calculate the percentage of prepared canal outline (= PPO) and the amount of root canal transportation. Loss of working length, fracture rate and time spent on complete preparation were also recorded. RESULTS: The highest PPO values were found in the LS group (mean = 63% [95% CI: 55%; 70%]). Although not statistically significant, lower PPO values were detected for FM instruments (mean = 55% [95% CI: 49%; 62%]) and for hand files (mean = 53% [95% CI: 47%; 59%]). The incidence of root canal transportation exceeding 0.1 mm was significantly lower in the LS group than in the FM group. Loss of working length of 0.5 mm occurred in five cases (LS group: 4x; FM group: 1x). Two LS instruments fractured. Half the time was needed for root canal preparation with FM instruments than with hand files. CONCLUSIONS: Rotary FM instruments are suitable for preparing curved root canals. They provided results similar to LS instruments with minimal risk of instrument fracture but increased risk of root canal transportation.     

5种手持根管器械预备弯曲人工根管的效果

目的 比较５种手持根管器械的成形能力。方法 用光学显微镜观察５种手持根管器械常规法预备弯曲人工根管后的根管形态变化。结果 所有标本未发现根尖拉开、肘部形成和穿孔。Ｋ－Ｆｌｅｘ组有７５％的标本出现台阶，台阶的出现与在部树脂屑栓的形成有很密切的关系。Ｋ－Ｆｌｅｘ组和Ｈ锉的组的根尖偏移较大，与Ｋ针组比较，有显著性差异，其余各组之间无显著性差异，其余各组之间无显著性差异。结论 通过综合评价５和睥持根管器械     

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。     

手用ProTaper镍钛器械预备弯曲根管的临床研究

目的:观察手用ProTaper镍钛器械预备弯曲根管的临床效果。方法:117例患者分为两组,手用ProTaper镍钛(PT)组59例,采用手用ProTaper镍钛器械预备根管,不锈钢K型根管锉(SS)组58例,采用改良双敞法预备根管。记录操作时间、器械折断情况、根管偏移发生情况、术后疼痛的发生、根管充填效果。结果:根管预备时间PT组为(5.59±1.66)min,SS组为(11.88±2.36)min;断针率PT组为3.39%,SS组为0;根管偏移率PT组为3.39%,SS组为17.24%;根充术后疼痛率PT组为5.08%,SS组为20.69%。结论:用手用ProTaper预备弯曲根管成形效果好,操作时间短,能很好地维持根管的走向和弯曲度,极少发生根管偏移等并发症,与目前较常用的K锉/改良双敞法相比有着明显的优势,可作为临床上预备弯曲根管的有效方法。但要注意预防因器械疲劳造成的折断,在形态复杂的根管中须小心操作。     

A study of the shape of prepared canal of commonly used hand endodontic instruments]

OBJECTIVE:Straight or slightly curved single root canals of teeth (<20 degree) were instrumentated with three commonly the hand endodontic instruments,which included K reamer,K file and H filel.The shape of prepared canal and root canal deviation at three levels were measured by computerized digital image processing program.The results demostrated that any significant differences were not found on root canal deviation in either labio-lingual or mesiodistal direction at each level,and that the shape of prepared canal was not different significantly.Apical transportation of the severely curved artificial root canals(25-30 degree) showed that H file was the most severe,K reamer was the least.It is suggested in this article how we select endodontic instruments rationally and effectively.     

Does the first file to bind correspond to the diameter of the canal in the apical region?

AIM: The aim of this study was to determine whether the first file that binds at the working length corresponds to the canal diameter. METHODOLOGY: Two similar groups (n = 10) of mandibular premolars with curved canals were selected on the basis of their morphology. Following access and pulp tissue removal, the first instrument that bound in each canal at the working length was determined. In one group the instrument used was a K-file, in the other group a Lightspeed instrument was used. After fixing the instruments in place, the apices were ground to the level of the working length and the diameters of both the instrument and the apical canal were recorded. RESULTS: In 75% of the canals, the instruments bound at one side of the wall only; in the other 25%, the instrument did not contact the wall. In 90% of the canals, the diameter of the instrument was smaller than the short diameter of the canal; this discrepancy was up to 0.19 mm. No significant difference in discrepancy was found between instruments (P > 0.05). CONCLUSIONS: Neither the first K-file nor the first Lightspeed instrument that bound at the working length accurately reflected the diameter of the apical canal in curved mandibular premolars. It is uncertain whether dentine can be removed from the entire circumference of the canal wall by filing the root canal to three sizes larger than the file that binds first.     

K-Flex和Unifile预备弯曲人工根管的研究

目的:比较K-Flex和Unifile用常规预备弯曲人工根管的切削能力和根尖偏移.方法:用电子分析天平称量K-Flex和Unifile预备弯曲人工根管后的标本失重量及在光学显微镜下测量K-Flex和Unifile预备弯曲人工根管后的根尖偏移.结果:K-Flex和Unifile的切削能力比较无显著性差异(P＞0.05),根尖偏移随着锉号的增大而增大,25#锉之前,两组之间的根尖偏移非常接近,但30#锉以后,K-Flex组的根尖偏移明显增大.结论:Unifile用常规法预备弯曲人工根管的效果优于K-Flex.     

Changes in root canal morphology in simulated curved canals over-instrumented with a variety of stainless steel and nickel titanium files

The purpose of this project was to observe the amount of apical and mid-curve transportation produced by a range of nickel titanium (NiTi), titanium alloy and stainless steel (SS) files. Tests were carried out in simulated curved root canals produced in epoxy resin blocks. Seven commercially available file types were tested using sizes 15 to 40. Instrumentation was carried out to 1 mm beyond the apex. Changes in canal dimensions were measured at 10x magnification under a shadowgraph. There were substantial differences in the amount and the pattern of apical and mid-curve transportation produced. The amount of transportation increased with each subsequent size of file. Under the same conditions, nickel titanium files produced significantly less transportation than stainless steel files. The least apical transportation was obtained with the NiTi Mity Turbo and the most by the SS K file and SS Hedstrom file. The least mid-curve transportation was produced by the NiTi Mity Turbo and the most by the SS Hedstrom file.