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。     

可变锥度联合标准锥度的镍钛器械预备"S"形树脂根管的成形效果

目的：评价可变锥度ProTaper镍钛锉联合标准镍钛K锉在S形树脂根管中的成形效果。方法：选择S形树脂根管30个随机分为3组，分别使用手用ProTaper锉、手用ISO标准镍钛K锉、ProTaper锉联合ISO标准镍钛K锉进行根管预备。分析预备后根管内外侧树脂去除量和根管宽度，评估根管成形效果。结果：ProTaper成形锉去除树脂量在相同型号的器械中最少；ProTaper修形锉对根管弯曲内侧和根尖外侧的树脂去除量最大；ProTaper锉联合标准镍钛K锉对以上部分的树脂去除量最少，预备后的根管宽度从根管口到根尖孔逐渐减小。结论：ProTaper成形锉结合ISO标准镍钛K锉对S形树脂根管有较好的成形效果。     

手用ProTaper镍钛锉在治疗弯曲根管中的应用

目的 探讨手用ProTaper镍钛锉在治疗弯曲根管中的效果。方法 将101例患者的132个弯曲根管随机分为两组,实验组68颗用手用ProTaper镍钛锉,对照组64颗用不锈钢K锉,两组均采用冠根向深入法进行根管预备,比较两组在根管预备时间、根管形态、预备后疼痛以及根充效果的差异。结果 手用ProTaper镍钛锉根管预备形态较好,预备时间减少,预备后疼痛发生率降低,根充恰填率明显增高。两组具有显著性差异(P<0.05)。结论 手用ProTaper镍钛锉组可有效改善弯曲根管治疗效果。     

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。     

3种机用镍钛锉对弯曲根管成形能力的比较

目的:比较Twisted File(TF)、ProTaper和Mtwo这3种机用镍钛锉对弯曲根管的成形效果。方法:树脂模拟弯曲根管,分别用TF锉、ProTaper锉、Mtwo锉进行预备,测量预备前后工作长度、根管中轴线和根管弯曲度的变化量。结果:根备后工作长度丧失量:TF组少于Mtwo组(P<0.05);根管中轴线的变化量:根尖部TF组少于Mtwo和ProTaper组(P<0.05),弯曲部TF组与ProTaper组少于Mtwo组(P<0.05);根管弯曲度改变量:TF组与ProTaper组少于Mtwo组(P<0.05)。结论:TF锉在预备弯曲根管时,能够较好地维持根管原始走向,防止根尖偏移,是较理想的弯曲根管预备器械。     

两种根管器械预备后牙根管的体会

目的：比较不锈钢K锉（SS）,ProTaper手用镍钛锉（PT）,预备后牙根管的临床效果。方法：选取需做根管治疗的前磨牙、磨牙110颗,随机分为两组,每组55颗牙。PT组用ProTaper手用镍钛锉冠向下预备技术预备根管。SS组用不锈钢K型锉逐步后退技术预备根管。两组均采用标准牙胶尖侧向加压技术进行根管充填。记录两组根管预备所需时间和根管充填后的效果,进行统计学分析。结果：PT组单根管预备所需时间（6.17±1.31）min,明显低于SS组（13.22±2.32）min,（P〈0.05）,PT组根管适充率（90.91%）,明显高于SS组（70.91%）,（P〈0.05）。两组比较差异有统计学意义。结论：ProTaper手用镍钛锉在后牙根管预备中有明显的优越性,省时省力,具有良好的成形能力和根管清理效果,适充率高。     

ProTaper手动镍钛锉与ISO标准锉根管预备技术的对比实验研究

目的:比较ProTaper手动镍钛锉与ISO标准手用不锈钢K型锉根管预备技术的效果。方法:将40个含弯曲管的透明塑料模块随机分为两组, 每组20个,A组为ProTaper手动镍钛锉预备组(PT组);B组为手用不锈钢K型锉预备组(SS组)。记录每组根管预备所需的时间,预备后根管形态的变化,以及推出根尖液体和碎屑的量。结果:PT组根管预备所用时间明显小于SS组(P<0. 05);预备后弯曲根管被直化的程度PT组明显小于SS组(P< 0. 05 );预备过程中PT组推出根尖液体和碎屑的量显著少于SS组(P<0. 05)。结论:与传统手用不锈钢锉相比,ProTaper手动镍钛锉在根管预备方面有明显的优越性。     

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。     

机用ProTaper锉和Flexofile不锈钢锉根管成形能力的对比研究

目的比较机用ProTaper锉和Flexofile不锈钢锉在弯曲树脂模拟根管中的成形能力。方法将40个树脂模拟根管随机分为两组,分别使用机用ProTaper锉以冠向下技术预备和Flexofile不锈钢锉以平衡力技术预备。预备过程中记录工作长度的变化和器械变形及分离的发生,预备结束后使用Image Pro Plus 5.0软件测量根管弯曲度和弯曲半径的变化以及内外侧壁树脂去除量,并计算器械中心定位力以及树脂去除总量。结果机用ProTaper锉与Flexofile不锈钢锉相比,能够保持较好的工作长度,较少发生根管不良形态,根管直化度较小,具有较好的中心定位力,预备后的根管具有较好的锥度形态。结论机用ProTaper锉具有良好的根管成形能力,可有效地预备弯曲根管。     

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。     

两种机用镍钛根管预备器械预备"S"形树脂根管的效果观察

目的探讨两种镍钛根管预备器械（ProTaper与Hero642）预备“S”形树脂根管的成形效果。方法将30个“S”形树脂根管模型分为3组，分别使用机用ProTaper（A组）、Hero642（B组）及ProTaper联合Hero642（C组）预备根管。使用扫描仪扫描获取根管图像，使用计算机软件测量预备后根管内、外侧树脂去除量和根管宽度。结果对比相同型号的器械对根尖部弯曲内侧、根尖孔外侧壁树脂去除量，C组与A组差异有统计学意义（P〈0．05），C组对根管内外侧壁的预备较均匀，预备后的根管宽度从根管口到根尖逐渐减小，优于B组预备的根管锥度。结论ProTaper联合Hero642预备“S”形树脂根管时能在维持根管原形的基础上形成锥度良好的管形。     

手用ProTaper对弯曲根管成形能力评价的研究

目的评价手用ProTaper对弯曲根管的成形能力。方法将16个弯曲人工根管随机分为2组,实验组(PT组)使用手用ProTaper按冠根向深入法预备根管,对照组(SS组)用不锈钢K锉按逐步后退法预备根管;根管预备过程中对人工根管进行数码照相,图像分析软件Image-ProPlus对根管的形态与位置变化进行测量、分析。结果PT组预备完毕时根管弯曲角度均值从预备前的36°减小到26°,弯曲半径均值未见增大,根管壁光滑、流畅,未见根管不良形态形成;SS组预备完毕根管弯曲角度均值减小到22°,弯曲半径均值从6mm增大至11mm,根管壁切削不均衡,出现了根管偏移、根尖孔拉开、根管台阶等不良形态。结论手用ProTaper对弯曲根管成形能力优于不锈钢K锉。     

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.     

ProTaperNext锉和WaveOne锉根管成形能力的对比研究

目的:比较机用ProTaperNext和WaveOne在弯曲树脂模拟根管中的成形能力。方法:选取统一规格的透明树脂模拟根管40个,将其随机分为2组,分别使用ProTaperNext和WaveOne锉以冠向下技术预备两组树脂模拟根管。使用ImagePro Plus软件测量根管弯曲半径和弯曲度的变化以及各测量点去除树脂量,计算树脂去除总量和两组器械的中心定位力,同时记录和分析根管工作长度的变化和器械变形、分离等参数。结果:两种器械预备根管时,均能保持较好的工作长度,不易发生器械分离,能够较好的维持根管原始走形,但在根尖段,WaveOne预备后的根管较易发生偏移。结论:ProTaperNext与WaveOne相比,在预备重度弯曲根管时具有良好的根管成形能力。     

ProTaper机动镍钛锉在乳牙根管预备中的应用

目的:比较ProTaper机动镍钛锉与手用不锈钢锉在乳牙根管预备中的效果.方法:选择42名4～7岁的儿童50个患有牙髓炎、根尖周炎的下颌第一乳磨牙.随机分成2组,分别用ProTaper机动镍钛锉(A组)与手用不锈钢锉(B组)进行根管预备,使用注射型根管充填剂(Matapex充填剂)进行根管充填.比较两组病例根管预备的时间,X线片观察两组根管充填效果.结果:A组根管预备的时间明显少于B组,差异有显著性(p＜0.01).根充效果观察,下颌第一乳磨牙近中根的恰填率A组高于B组,差异有显著性(P＜0.01).远中颊舌根恰填率A组与B组差异无显著性(P＞0.05).结论:ProTaper机动镍钛锉进行根管预备及使用注射型乳牙根管充填剂充填根管,能大大提高乳牙根管治疗的效率和效果.     

Cutting pattern of nickel-titanium files using two preparation techniques

Abstract— The aim of this study was to examine the cutting patterns of recently introduced nickel-titanium endodontic files and compare them with similarly shaped stainless steel files using both balanced-force and stepback techniques. Simulated canals were constructed in resin blocks with 40° curvature. Fifty blocks were prepared by a balanced-force technique: 25 with Nitiflex (Maillefer) and 25 with Flexofiles (Maillefer) to a master apical file size 40. Fifty blocks were prepared by a stepback technique: 25 with Nitiflex and 25 with Flexofiles to a master apical file size 30. Composite prints were made of pre- and post-instrumentation canals using a computerized imaging system. The amount of material removed from the inner and outer canal curvatures was measured at eight levels in the apical 11 mm of the canal. The results were analysed by Krus-kal-Wallis ANOVA. Using the balanced-force technique, Nitiflex files removed less material on the outer curve apically and less on the inner curve mid-canal (P<0.05), while Flexofiles caused more apical transportation. In the stepback technique, the Nitiflex files removed more material from the outer curve apically (P<0.05); the Flexofiles removed more material along the entire inner curve (P<0.05), and maintained canal curvature better than Nitiflex files. It appeared preferable to use Nitiflex files in a balanced-force technique, and Flexofiles in a filing technique as stainless steel files can be precurved.     

Root canal shaping with manual stainless steel files and rotary Ni-Ti files performed by students

AIM: To investigate root canal shaping with manual stainless steel files and rotary Ni-Ti files by students. METHODOLOGY: Two hundred and ten simulated root canals with the same geometrical shape and size in acrylic resin blocks were prepared by 21 undergraduate dental students with manual stainless steel files using a stepback technique or with rotary Ni-Ti files in crown-down technique. Preparation length, canal shape, incidence of fracture and preparation time were investigated. RESULTS: Zips and elbows occurred significantly (P < 0.001) less frequently with rotary than with manual preparation. The correct preparation length was achieved significantly (P < 0.05) more often with rotary Ni-Ti files than with manual stainless steel files. Fractures occurred significantly (P < 0.05) less frequently with hand instrumentation. The mean time required for manual preparation was significantly (P < 0.001) longer than that required for rotary preparation. Prior experience with a hand preparation technique was not reflected in an improved quality of the subsequent engine-driven preparation. CONCLUSIONS: Inexperienced operators achieved better canal preparations with rotary Ni-Ti instruments than with manual stainless steel files. However, rotary preparation was associated with significantly more fractures.