TF和S3预备磨牙重度弯曲根管的效果评价

目的 比较Twisted File(TF)、萨尼S3 2种机用镍钛锉预备重度弯曲根管的成形效果及牙根微裂情况。方法 按照Schneider测量法,选取近颊(MB)根管弯曲度>25°的60颗上颌磨牙,随机分为TF组(n=30)和S3组(n=30),2组均采用冠向下法预备根管,预备前后进行锥形束CT(cone-beam CT,CBCT)扫描,记录距离根尖孔3、5、7 mm处根管偏移值。所有离体牙在距根尖顶点3、5、7 mm 处垂直牙体长轴做横切片,显微镜下观察并记录牙根裂纹形成情况,评估TF、S3镍钛锉的根管预备效果。采用SPSS 19.0软件包对数据进行统计学分析。结果 所有根管均存在偏移,TF组和S3组在距离根尖孔3 mm处偏移有统计学差异(P<0.05),TF组牙根微裂发生率为20%(6/30),TF组牙根微裂发生率为13.3%(4/30),2组间牙根裂纹发生率差异无统计学意义(P>0.05)。结论 在离体牙重度弯曲根管预备中,TF和S3均有微裂纹产生,S3较TF能更好地维持根管原有走向。     

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.     

根尖预备尺寸对玷污层清除效果的比较研究

目的:比较5种不同根尖预备方案对根管玷污层的清除效果。方法:将50颗单根管上颌离体前牙随机分为5组,A组:采用机动ProTaper系统将根尖预备至25^#(F2),配合次氯酸钠+EDTA冲洗;B组:根尖预备至30^#(F3),预备及冲洗方法同A组;C组:采用机动ProTaper系统将根尖预备至F3,后用不锈钢K锉预备根尖至35^#,冲洗同A组;D组:采用机动ProTaper系统将根尖预备至F3,后用不锈钢K锉预备根尖至40^#,冲洗同A组;E组:根管预备同D组,冲洗用蒸馏水。利用热场发射扫描电子显微镜,评估玷污层清除情况。结果:B组、C组和D组均明显优于A组 (P<0.05);A组、B组、C组和D组明显优于对照E组(P<0.05)。结论:机动ProTaper将根管预备至30^#,可使足量的冲洗液渗入根尖1/3区,有效去除玷污层及碎屑。     

两种旋转方式镍钛器械根管成形能力及根尖推出物重量体外研究

目的:评估不同运动方式镍钛预备器械预备后根管形态变化及根尖推出物重量的差异。方法:选择单弯树脂模拟根管20个,将样本随机分为A、B两组(n=10):A组采用ProTaper Gold预备至40^#/0.06锥度;B组采用Reciproc Blue预备至40^#/0.06锥度。采用牙科显微镜拍摄预备前后根管图片,分析根管上段、中段及下段形态的变化;收集根管预备过程中的碎屑及冲洗液,分析各组根尖推出物重量的差异。结果:A组和B组根管弯曲角变化值差异无统计学意义(P>0.05)。A组在距根尖6 mm、7 mm处的中心定位能力优于B组(P<0.05);B组在距根尖1 mm、2 mm处的中心定位能力优于A组(P<0.05)。A组根尖孔推出碎屑量及冲洗液量和B组间差异无统计学意义(P>0.05)。结论:往复运动镍钛器械Reciproc Blue在根尖段的中心定位能力更好,连续旋转镍钛器械ProTaper Gold在根中段的中心定位能力更好。     

不同充填体系根管充填后纤维桩修复的根尖封闭能力比较

目的:比较不同根管充填体系进行根管充填后行纤维桩修复的牙体根尖微渗漏情况.方法:收集32颗下颌第一前磨牙,截冠、拔髓,随机分成3组(GP组,R/E组,F组,n=10),根管预备后,分别采用牙胶+ AH-plus、Resilon/Epiphany、Fibrefill充填根管并行即刻桩道预备和粘固纤维桩;印度墨水染色并透明处理后显微镜下测定根尖微渗漏的长度并统计学分析.另外两颗做为阳性对照.结果:GP组显示出最高渗漏发生率(100%),F组最低(60%);GP组的渗漏长度明显高于R/E组(P =0.002)和F组(P =0.001),R/E组与F组之间无显著性差异(P = 0.879).结论:Resilon/Epiphany系统和Fibrefill系统对于根管治疗并纤维桩修复的牙体较牙胶有更好的根尖封闭性能,二者之间差异无显著性.     

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。     

平衡力法预备弯曲根管的临床评价

目的：评价用平衡力法预备弯曲根管的临床疗效。方法：选取有弯曲根管的牙髓炎和根尖周炎患牙48个，试验组用弹性K锉(Flexofile)，使用平衡力法预备根管；对照组用K挫，逐步后退技术预备根管，两组均用侧向加压充填法充填根管，根据治疗前、中、后的x线片评价根管预备和充填的效果。结果：两组在根管预备中无器械折断。试验组无根尖阻塞、台阶形成等并发症发生，发生根管偏移少，能较好地维持根管的弯曲度和走向。对照组1例有台阶形成，发生根管偏移的明显多于试验组(P＜0．05)。结论：平衡力法预备弯曲根管可以节约成本，缩短操作时间，较好地维持根管的定向和弯曲度，减少根管偏移。安全有效，实用性强，可作为临床上预备弯曲根管的有效方法。     

即刻与延迟桩腔预备对3种根充糊剂加牙胶根充后根尖封闭性影响的研究

目的 评价即刻桩腔预备与延迟桩腔预备对3种根充糊剂充填根管根尖封闭性的影响。方法 选取离体直根管牙105颗,截冠后随机分为5组。A组:牙胶尖+AH Plus根充(n=30);B组:GuttaFlow+单牙胶尖根充(n=30);C组:牙胶尖+ZOE根充(n=30)。D组:为阳性对照,牙胶尖根充(n=10);E组:为阴性对照,牙胶尖根充(n=5)。其中A、B、C各组内分别随机分为A1、A2、A3,B1、B2、B3,C1、C2、C3组(n=10)。各组均采用手用Protaper冠向下法预备根管。对A1、B1、C1组行即刻桩腔预备;A2、B2、C2组根充1周后行延迟桩腔预备。A3、B3、C3、D、E组不做桩腔预备。利用印度墨水染色,透明牙技术评价经即刻桩腔预备与延迟桩腔预备后剩余根充材料的根尖微渗漏情况。结果 即刻与延迟桩腔预备在相同根充材料之间对根尖的封闭性影响无统计学差异(P>0.05);相同预备时机不同材料组间比较AH Plus组和GuttaFlow组好于ZOE组(P<0.05),AH Plus组和GuttaFlow组间无统计学差异(P>0.05)。结论 即刻与延迟桩腔预备对相同根充材料根尖封闭性的影响无统计学差异。建议根充后行即刻桩腔预备并使用AH Plus或GuttaFlow做根充糊剂。     

即刻桩腔预备对三种根管预备方法预备的直根管根尖封闭性的影响

目的 研究三种不同根管预备方法根管预备、根管充填后即刺桩腔预备对直根管根尖封闭性的影响.方法 离体直单根管上前牙124个,其中120个随机平均分为3组(n=40),A组:不锈钢根管锉常规法;B组:G 型钻根管冠部预处理 不锈钢根管锉常规法;C组:手用Pr01raper镍钛根管锉冠向下法,刺余4个随机平均分为阴性对照组和阳性对照组.所有根管均用侧方加压法充填,即刻手持垂直加压器去除部分充填材料,然后P型钻桩腔预备.用染料渗透法评价各组根尖封闭能力.结果 B组G型钻根管冠部预处理 不锈钢根管锉常规法预备的根管和C组手用ProTaper镍钛根管锉冠向下法预备的根管即刻桩腔预备后,其根尖微渗漏较A组常规法预备的轻(P<0.05).结论 大锥度根管预备,根管充填后即刻桩腔预备的根尖封闭性较好.     

不同预备方法对根管治疗诊间急症和充填效果的影响

目的： 比较不同根管预备方法对根管治疗诊间急症(interappointment emergencies,IAE)发生率和根管充填效果的影响。方法： 2018年8月—2021年8月因牙髓炎或根尖周炎需要做根管治疗的恒磨牙96颗,随机分为2组（n=48）颗,MT组使用 Mtwo机用镍钛锉改良 Mtwo根管预备法,同步组使用改良 Mtwo预备技术加同步根管长度测量根管预备法。根管预备完成后拍摄根尖片,根管内封入氢氧化钙,复诊时行常规热牙胶根管充填。采用 SPSS 22.0 软件包分析IAE的发生情况及术后充填效果。结果： 术后即刻及术后第3 天、1周,2组IAE发生率无显著差异（P>0.05）;术后第1、2 天,同步组IAE发生率显著低于MT组（P<0.05）,同步组根管充填的合格率显著高于MT组（P<0.05）。结论： 同步法能减少根管预备过程中根尖区的机械刺激,严格控制根管的工作长度,维持根尖区屏障,从而降低IAE发生率并有效提高根管充填合格率。     

2种不同根管预备技术与牙根纵折的原因分析

目的:探讨根管治疗术后牙根纵折的发生与不同根管预备技术的相关性,为临床治疗提供依据。方法:对2年间共1702颗(例)牙根管治疗术后病例进行调查,将其按根管预备技术分为镍钛旋转预备技术组(643例)和手用不锈钢预备技术组(1059例)。通过临床症状、体征和影像学结果进行评估。采用SPSS11.5软件包对数据进行统计学分析。结果:共发生牙根纵折32例(1.88%);镍钛旋转器械预备组牙根纵折率显著高于手用不锈钢器械预备组(P<0.01);镍钛旋转器械预备组根管再治疗的牙根纵折率显著高于手用不锈钢器械预备组(P<0.01),但2组的根管桩核修复病例的牙根纵折率无显著差异(P>0.05)。结论:镍钛旋转器械预备技术与术后根折并发症密切相关,如合并根管再治疗史和(或)根管内桩核修复,牙根纵折的风险更大。     

Influence of phase transformation on the torsional and bending properties of nickel-titanium rotary endodontic instruments

AIM: To investigate the relationship between the functional properties and the phase transformation of nickel-titanium endodontic instruments. METHODOLOGY: Five types of rotary nickel-titanium endodontic instruments with a 0.30 mm diameter tip (EndoWave, HERO 642, K3, ProFile.06, and ProTaper) were selected to investigate torsional and bending properties, and phase transformation behaviour. A torsional test was performed according to ISO publication 3630-1, and maximum torque and angular deflection at fracture were measured. Bending load of the instruments was measured in a cantilever-bending test at 37 degrees C with the maximum deflection of 4.0 mm. A stainless steel K-file was used for reference. Phase transformation behaviour was measured by differential scanning calorimetry (DSC). From the DSC curve, transformation temperatures were calculated. Data were analysed by anova and the Tukey-Kramer's test. RESULTS: The maximum torsional torque values of HERO, K3 and ProTaper were significantly higher (P < 0.05) than those of EndoWave, ProFile and K-file. The K-files had the lowest torque value. Angular deflection at fracture was significantly higher (P < 0.05) for K-files than that for any nickel-titanium instrument. The bending load values of HERO and K3 were significantly higher (P < 0.05) than those of EndoWave, ProFile, ProTaper and K-file. The K-files had the lowest load value, although residual deflection remained. The transformation temperatures of HERO and K3 were significantly lower (P < 0.05) than those of EndoWave, ProFile and ProTaper. CONCLUSIONS: The functional properties of nickel-titanium endodontic instruments, especially their flexible bending load level, were closely related to the transformation behaviour of the alloys.     

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 micro-computed tomographic evaluation of apical root canal preparation using three instrumentation techniques

Aim  To investigate the morphological changes in the apical third of the root canal after preparation with three techniques.
Methodology  Forty molar teeth were scanned using micro-computed tomography before and after instrumentation with: Group 1 – stainless steel K-files using the balanced force technique; Group 2 – stainless steel K-files (balanced force) and then refining the apical preparation with the equivalent size 0.04 taper FlexMaster instrument; Group 3 – a hybrid ProTaper/FlexMaster (ProFile for sizes 45 and 60) sequence. Eight canals were excluded because of artefacts in the images or unnegotiable blockages leaving 110 canals that could be analysed. Apical root canal preparation was evaluated with respect to the amount of dentine removed, canal roundness, transportation and how the dimensions of the prepared apical root canal correlated with those of the final instrument used.
Results  The median apical preparation sizes for the three groups respectively were: 30, 30 and 40. Despite the larger size and less experienced operator, the volumetric change (the amount of dentine removed) in canals prepared with a hybrid rotary nickel–titanium instrumentation technique remained small and, a more rounded preparation ( P  < 0.001) that closely matched the final instrument dimensions ( P  < 0.001) was produced. There was a trend for less canal transportation using rotary nickel–titanium instruments.
Conclusions  Stainless steel hand preparation was not conservative of apical dentine. When used correctly, even by less experienced operators, rotary nickel–titanium instruments were able to precisely 'machine' a canal to larger apical sizes with minimal risk of iatrogenic damage.     

Comparison between rotary and manual instrumentation in primary teeth

The aim of this study was to compare the efficiency in both, preparation time and root canal shape, when using the Nickel Titanium (Ni-Ti) rotary and K-Files hand instrumentation on root canal preparation of single rooted primary teeth. MATERIAL AND METHODS: Sixty single rooted primary teeth were selected and divided into two equal groups: Group (I) 30 teeth instrumented with manual K-files and group (II) 30 teeth instrumented with Ni-Ti rotary files (ProFile 0.04). Instrumentation times were calculated and root canal impressions were taken with light bodied silicone in order to evaluate the shape. The data was analyzed with SPSS program using the t-test and the Chi-square test to compare their means. RESULTS: The preparation time with group (I) K-files was significantly higher than in group (II) rotary files (ProFile 0.04), with a p= .005. The ProFile system showed a significantly more favorable canal taper when compared to the K-files system (P= .002). CONCLUSIONS: The use of rotary files in primary teeth has several advantages when compared with manual K files: the efficiency in both, preparation time and root canal shape. 1. A decreased working time, that helps maintain patient cooperation by diminishing the potential for tiredness. 2. The shape of the root canal is more conical, favoring a higher quality of the root canal filling, and increasing clinical success.     

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。     

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 stainless steel and nickel-titanium K-files in curved root canals

The purpose of this study was to determine the effects of hand instrumentation using traditional stainless steel K-files and nickel-titanium K-files on the final shape of curved root canals. A total of 24 moderately curved canals in the mesial roots in extracted human mandibular first molars were randomly divided into two groups. These were instrumented manually using either stainless steel or nickel-titanium, K-files with the stepdown technique. The cross-sectional shape of each canal at three different horizontal levels were captured, before and after instrumentation, into a computer for comparison using image analyser software. Three parameters at each level were evaluated: (i) amount of dentine removed; (ii) least remaining dentine thicknesses on mesial and furcal aspects; and (iii) the amount and direction of canal transportation. The results showed that the two file types removed similar amounts of dentine at all three levels examined. The nickel-titanium files left a thicker layer of dentine on both the mesial and furcal aspects than stainless steel files. However, the difference was not significant (pooled T-test, P > 0.05). Both types of files transported the centre of the canals but the nickel-titanium instrument seemed to be safer because of the reduced amount of transportation towards the danger areas.     

Modeling capacity of ENDOflash files in simulated root canals

With the development of rotary nickel-titanium files and their applications in Endodontics, the concepts of root canal preparation have changed. The objective of this research is to evaluate the transportation of simulated root canals caused by stainless steel ENDOflash rotary files compared to nickel-titanium ProFile files (.04, .06 and Orifice Shapers). Twenty-four simulated root canals with a 30 degrees curvature were randomly divided into 2 groups and prepared with ENDOflash or ProFile files according to manufacturers' instructions. Comparison between the simulated root canals before and after instrumentation showed significant differences (p < 0.001) between the groups, with greater transportation observed with ENDOflash files. One case of deformation was observed with a ProFile instrument (#20/.04) and there were no fractures.     

The effectiveness of manual and rotary techniques in the cleaning of root canals: a scanning electron microscopy study

AIM: The purpose of this scanning electron microscope (SEM) study was to compare the cleanliness of the root canal walls following either a manual or a rotary technique of canal instrumentation. The hypothesis was that a rotary technique would produce a cleaner root canal. METHODOLOGY: Manual filing was performed on 10 extracted teeth using stainless steel S-files (Sjodings, Sendoline, Sweden). Powered instrumentation was carried out on a further 10 extracted teeth, using ProFile rotary nickel-titanium files in a handpiece (250 r.p.m.) according to the manufacturer's instructions. A solution of 0.5% sodium hypochlorite was used for irrigation. The roots were cut longitudinally and the canal walls were examined for debris and smear layer at the apical, middle and coronal level. RESULTS: Significantly less debris was found in the apical region using the manual filing technique (P < 0.05); no significant differences could be found at the other levels. Overall, significantly less debris was found on the root canal walls using the manual technique when the data from the three levels were compared (P = < 0.05). CONCLUSIONS: The manual technique employed in this study produced cleaner root canal walls than the rotary ProFile technique.