根管冠部预处理对前磨牙弯曲根管预备效果的影响

目的:研究根管冠部预处理对预备弯曲前磨牙根管时根尖偏移的影响。方法:将60个15°～35°的弯曲前磨牙根管按弯曲度排序后分成15个区组,每区组4个根管,再随机分配至4个不同处理组。其中2组根管冠部用GG钻预处理后,分别用不锈钢和镍钛合金K锉行常规法预备根管;另2个对照组直接行常规法根管预备;记录各组根管预备至不同锉号时的根管影像及器械尖端所在位置。最后,测量比较根管预备前后弯曲度的变化和不同锉根管预备后的根尖偏移指数(ATI)。采用t检验或配对资料的符号秩和检验进行统计学处理。结果:各组根管预备前后的弯曲度之间均有显著差异(P<0.01),ATI均随锉号的增大而增大。用不锈钢锉预备根管,经过冠部预处理,根管侧穿数目明显少于对照组,且30#锉所致的根尖偏移显著低于对照组(P<0.01),与同型镍钛合金K锉所产生的根尖偏移无差异(P>0.05)。结论:对于前磨牙弯曲根管,用镍钛合金锉预备,其效果优于不锈钢锉;不论是镍钛合金K锉还是不锈钢K锉,在用常规法预备弯曲前磨牙根管时,均应进行根管冠部预处理。     

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目的    研究根管冠部预处理对预备磨牙弯曲根管根尖偏移的影响。方法    从2006—2008年就诊于沈阳市口腔医院颌面外科121例患者因牙周病拔除的135颗磨牙中选取72个12  ~ 35°的弯曲磨牙根管，按照Schneider测量根管弯曲方法分成中度弯曲组（12  ~ 20°）和重度弯曲组（21 ~ 35°），每组36个根管，各组再按随机原则分为试验组和对照组，各18个根管。试验组：根管冠部用GG钻预处理，常规用10 ~ 35号不锈钢K锉进行根管预备；对照组：直接行常规法根管预备。记录各组根管预备至不同锉号时的根管影像，测量并比较各组不同锉号预备后的根尖偏移指数（ATI）。结果    中度弯曲组和重度弯曲组中，经冠部预处理的试验组ATI均明显小于对照组，差异有统计学意义（P < 0.05）；随锉号的不断增大，根尖偏移指数也逐渐增大，且试验组根管侧穿数明显小于对照组。结论    磨牙弯曲根管预备时经冠部预处理的根管预备效果优于常规处理。     

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。     

应用锥形束CT评价两种机用镍钛根管锉的根管成形能力

目的:应用锥形束CT评价Twisted File(TF)和Pro Taper两种机用镍钛锉的根管成形效果。方法:选择符合标准的离体牙41个(共60个单根管牙根),按弯曲度分为轻度弯曲(0°~15°)组和重度弯曲(16°~35°)组(n=30):每个大组再随机分为两个亚组(TF组和Pro Taper组,n=15)。机用TF锉和Pro Taper锉分别预备根管,预备前后进行CBCT扫描,测量距根尖2、4、6 mm处根管近、远中侧的根管壁厚度,计算各处的轴中心率,比较其差异。结果:TF和Pro Taper机用镍钛根管锉中心定位能力间差异均无统计学意义(P>0.05),TF预备轻度弯曲根管时的中心定位能力优于重度弯曲根管(P<0.05);Pro Taper预备轻度弯曲根管在距根尖2、4 mm处的中心定位能力优于重度弯曲根管(P<0.05),而6 mm处差异无统计学意义(P>0.05)。结论:两种机用镍钛根管锉均有较好的中心定位能力,牙根弯曲度<15°时的中心定位能力优于>15°者。     

三种器械预备磨牙弯曲根管成形能力的比较

目的　研究手用ProTaper与不锈钢K锉、镍钛合金K锉预备磨牙弯曲根管对根管弯曲度和根尖偏移的影 响。方法　45个弯曲度为20°~40°的磨牙根管,按弯曲度大小排序后分成15个区组,每区组3个根管,再随机分配 至3个不同处理组,每组15个根管。A组采用手用ProTaper系统行冠根向深入法根管预备;B、C组分别采用不锈钢 K锉和镍钛合金K锉行改良逐步后退法预备根管。记录3组根管预备前后根管影像及器械尖端所在位置,测量并 比较3组间根管弯曲度的变化、根尖偏移指数(ATI)和操作时间。结果　A组的根管弯曲度在根管预备前后仅改变 0·28°,明显低于B、C组,ATI亦小于B、C组(P<0·05);B组根管弯曲度的变化和ATI均大于A、C组(P<0·05);A组 的操作时间最短。结论　与不锈钢K锉、镍钛合金K锉比较,采用手用ProTaper预备磨牙弯曲根管成形效果较好, 效率较高。     

3种镍钛机动器械预备磨牙弯曲根管成形能力的比较

目的:比较3种机动镍钛预备系统(Mtwo、ProTaper和Hero642)预备磨牙弯曲根管的根尖偏移和根管弯曲度的变化.方法:采用3种镍钛机动预备系统预备磨牙弯曲根管,拍摄数字化X线片记录预备前、后分别将15#初尖锉和主尖锉置于根管中的根管影像.用Schneider法测量比较根管预备前、后弯曲度的变化,并将根管预备前后器械尖端相应位置描记后,在立体显微镜下借助测距装置测量根尖偏移指数(ATI).所有数据均采用SAS 6.12软件包进行统计学分析.结果:Hero642系统发生器械折断2枚.3种机动镍钛预备系统中,Mtwo系统根管预备的时间最短,预备1个根管仅需26.7s,ProTaper系统和Hero642系统分别需要28.12s和78.98s;经统计学分析,Hero642系统与另2组之间有显著差异(P＜0.01).3种镍钛机动器械预备前、后根管弯曲度的改变均有显著意义.Hero642系统的根尖偏移最大,ProTaper系统的根尖偏移最小.3组标本经方差分析,无显著差异(P＞0.05).结论:Mtwo和ProTaper机动镍钛预备系统用于预备后牙弯曲根管,效率高,成形能力强,是较理想的弯曲细小根管的预备器械.     

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。     

新型机用镍钛锉去除不同弯曲度的椭圆形根管充填物的效果研究

目的:评价新型机用镍钛锉Waveone Gold和Reciproc Blue在不同弯曲度的椭圆形根管中去除根充物的效果.方法:选取150颗单根管离体前磨牙,根据弯曲度分为3组:直根管组、中度弯曲组、重度弯曲组,每组各50颗牙.完善根管预备和充填后,各组再随机分为5组(n=10):手用H锉组、Protaper Universal Retreatment锉组、Mtwo R锉组、Waveone Gold锉组、Reciproc Blue锉组,分别去除根充物,记录时间及并发症,计算根管侧壁残留量.结果:不同弯曲度的椭圆形根管,H锉组所用操作时间及根管总体残留量明显高于其他机用锉组,差异有统计学意义(P<0.05),各机用锉组间比较差异无统计学意义.中度弯曲组Mtwo R锉组发生器械分离1例,重度弯曲组中Mtwo R组发生器械分离2例.结论:Reciproc Blue锉和Waveone Gold锉均能有效清除根管充填物,且在弯曲椭圆形根管中表现出较好的安全性.     

新型机用镍钛锉去除不同弯曲度的椭圆形根管充填物的效果研究

目的:评价新型机用镍钛锉Waveone Gold和Reciproc Blue在不同弯曲度的椭圆形根管中去除根充物的效果.方法:选取150颗单根管离体前磨牙,根据弯曲度分为3组:直根管组、中度弯曲组、重度弯曲组,每组各50颗牙.完善根管预备和充填后,各组再随机分为5组(n=10):手用H锉组、Protaper Universal Retreatment锉组、Mtwo R锉组、Waveone Gold锉组、Reciproc Blue锉组,分别去除根充物,记录时间及并发症,计算根管侧壁残留量.结果:不同弯曲度的椭圆形根管,H锉组所用操作时间及根管总体残留量明显高于其他机用锉组,差异有统计学意义(P<0.05),各机用锉组间比较差异无统计学意义.中度弯曲组Mtwo R锉组发生器械分离1例,重度弯曲组中Mtwo R组发生器械分离2例.结论:Reciproc Blue锉和Waveone Gold锉均能有效清除根管充填物,且在弯曲椭圆形根管中表现出较好的安全性.     

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。     

3种根管扩大器械预备弯曲根管的体外实验

目的：运用手持根管扩大器械预备弯曲根管，观察根尖偏移发生率，方法：选取57颗弯曲单根管离体前磨牙作为研究对象，随机分成三组，A组19颗用Lightspeed镍钛合金器械预备根管，B组运用K锉，C组运用H锉，C组运用H锉，预备方法均为逐步后退技术，使用双曝光技术判断根尖偏移情况，结论：A组中有19％的根管发生了根尖偏移，B组中有82％发生了根尖偏,C且中有88％发生了根尖偏移，结论：运用Lightspeed镍钛器械预备弯根管可以减少根尖偏移的发生。     

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.     

两种根管镍钛锉对L形和S形根管成形能力的研究

目的 评价两种机用镍钛锉对弯曲根管的预备成形能力.方法 20个L形树脂根管,随机分为2组,每组10个,分别使用#25,0.04锥度的M3铂金版、S3预备根管,术前术后拍摄数码照片,绘制根管外形线及中心线,分析根管预备前、后工作长度和弯曲角度变化值及根管中心线偏移量.另20个S形树脂根管,分组方法 和实验方法 同L形根管...     

The quality of apical canal preparation using hand and rotary instruments with specific criteria for enlargement based on initial apical file size

The aim of this study was to compare the quality of apical enlargement of mesiobuccal canals of mandibular molars using conventional stainless steel hand files (K files) and nickel-titanium (Ni-Ti) rotary instruments (LightSpeed). Thirty freshly extracted mandibular molars were randomly assigned to three equal groups (n = 10 each group). The mesiobuccal canals were instrumented with K file using step-back technique without coronal flaring (control; group 1), K file using step-back technique after coronal flaring (group 2), and LightSpeed instrumentation (group 3). Specific criteria for apical enlargement based on initial apical size were used. For step-back techniques, the master apical file sizes were based on the Grossman criterion of three sizes larger than the first file that bound at working length, without coronal flaring (group 1) and with flaring (group 2). For the LightSpeed (LS) group, the master apical rotary sizes were based on the manufacturer's recommendation. Canal cleanliness, canal transportation, and final canal shapes were determined histologically at 1-mm and 3-mm levels short of the working length. Canals were prepared to significantly larger sizes using LS instrumentation than with either hand instrumentation techniques (15-17 ISO units, p < 0.001). LS instrumentation allowed greater apical enlargement with significantly cleaner canals, less apical transportation, and better canal shape than both hand instrumentation groups at both levels (p < 0.05). None of the three techniques was totally effective in cleaning the apical canal space. It was concluded that greater apical enlargement using LS rotary instruments is beneficial as an attempt to further debride the apical third region in mesiobuccal canals of mandibular molars. Instrument designs, alloy properties, and canal curvature are important factors that determine the feasibility of greater apical enlargement in narrow canals.     

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。     

Leakage along warm gutta-percha fillings in the apical canals of curved roots

The aim of this study was to investigate the leakage along the apical portion of warm gutta-percha obturated curved canals. Human mandibular premolars with single, curved (21 degrees-40 degrees) canals were prepared using the Lightspeed technique. Two groups of prepared canals, matched according to curvature and prevalence of apical transportation, were obturated by two techniques. Coronal gutta-percha was removed immediately after root obturation was completed to simulate the procedure for post space preparation. Leakage along the apical 3 mm of root filling was measured with a fluid transport device. Vertical condensation of warm gutta-percha and Pulp Canal Sealer provided less leakage than Thermafil plastic obturators and AH26 sealer (P = 0.002).     

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。     

Evaluation of the incidence of transportation after placement and removal of calcium hydroxide

The purpose of this in vitro study was to evaluate the incidence of apical transportation after the placement and removal of Ca(OH)2 in straight and curved root canals. Twenty maxillary central incisors (group A) and 20 mesiobuccal canals from mandibular molars (group B) were instrumented at the working length to a #45 file and #30 file, respectively. Postinstrumentation radiographs were taken with the corresponding final file inserted into the canal to the working length. Afterward, the root canals were filled with a Ca(OH)2 paste using Lentulo spirals, and the teeth incubated for 7 days. The Ca(OH)2 paste was then removed up to the working length using a #45 file for group A and a precurved #30 file for group B. Final radiographs were taken with the file inserted into the canal to the working length. Postinstrumentation and final radiographs were superimposed to evaluate the incidence of transportation. As expected, in group A (straight canals) no transportation was detected, whereas in group B (curved canals) 9 of 20 canals showed apical transportation (95% confidence interval, 23.1-68.5% transportation). Statistically significant differences were observed between groups A and B (p < 0.05).     

The influence of root canal shape on the sealing ability of two root canal sealers

AIM: To evaluate the influence of root canal form on the sealing ability of two root canal sealers. METHODOLOGY: Twenty radiographically confirmed straight and 20 curved root canals were prepared with a stepback hand filing technique. Root canal aberrations created during preparation were determined by the use of double exposure radiographic technique. The prepared canals were filled with lateral condensation of gutta-percha and one or other of two root canal sealers (Pulp Canal Sealer and Sealapex). Leakage along the apical 10 mm of roots was measured with a fluid transport model at 1, 3, 6, 9 and 12-month intervals. RESULTS: There were no statistically significant differences between straight and curved root canals (P > 0.05) for prevalence of root canal transportation. The prevalence of apical transportation was 80% in the straight and 85% in the curved root canals. A complete seal was more frequently observed in straight canals compared with curved canals. Utilizing the pi* index, analysis showed the filling with Sealapex allowed more leakage than Pulp Canal Sealer at 1 year. CONCLUSION: Under the conditions of the study, root canal form influenced short-term sealing ability. In the long-term the seal was affected by the sealer rather than root canal form.     

Pathfile根管预备系统在下颌第一磨牙远中舌根预备中的应用研究

目的 研究应用Pathfile根管预备系统预备下颌第一磨牙远中舌根对器械分离、根尖偏移及根充效果的影响。方法 选取2014年12月26日至2015年9月25日就诊于天津市河西口腔医院治疗诊科患者104人,共104颗具有远中舌根的下颌第一磨牙,随机分为2组,A组（试验组）采用PathFile和ProTaper联合预备,B组（对照组）采用Protaper单独预备,分别记录两组的器械分离、根尖偏移、根管恰填的个数,进行统计学分析。结果 与对照组相比,A组具有较少的器械分离率及根尖偏移率（P<0.05）,2组的根管恰填率未见统计学差异（P>0.05）。结论 联合运用PathFile和ProTaper对下颌第一磨牙远中舌根进行预备可以有效减少器械分离率及根尖偏移率,值得临床推广。