4种机用镍钛锉根管预备后形成牙本质微裂的研究

目的 运用micro-CT比较T-Flex、Reciproc Blue (RB)、ProTaper Gold (PTG)和ProTaper Universal(PTU) 4种机用镍钛锉在体外根管预备后牙本质微裂形成方面的差异。方法 选用根管弯曲度不大于10°的新鲜离体双根管前磨牙32颗建立体外根管预备模型。根据所用镍钛系统将其随机分为T-Flex、RB、PTG、PTU组（n=8）。设置micro-CT体素大小为17.18μm,扫描分析预备前后牙根横断面图像（n=56 940）,观察牙本质微裂的存在。各组结果以存在裂纹的断层图像的数量及百分比来表示,McNemar检验用于比较预备前后牙本质裂纹的存在是否有显著差异,显著性水平设定为P<0.05。结果 总体有11.04%的图像显示有牙本质微裂（n=6 288）。T-Flex、 RB、 PTG和PTU组在预备后观察到具有牙本质微裂截面的比例各自为9.82%、 10.79%、 12.27%和11.25%。所有在预备后断层图像上发现的牙本质裂纹在相应的预备前图像中均已存在。使用上述镍钛系统预备前磨牙根管未出现新的微裂纹。结论 未经根管预备的...     

往复式与连续旋转式2类镍钛器械对根管预备效果的比较分析

根管预备是根管治疗过程中最关键的步骤之一,包括牙髓组织、微生物、感染牙本质和根管内旧充填物的清理以及根管成形。在这个过程中,若预备不当可能出现台阶、根管偏移、根尖孔敞开等并发症,影响根充质量和根尖封闭性。因此,选择具有良好的切削能力、成形能力以及优越机械性能的根管预备器械对于根管治疗效果的保证有着重要的意义。本文通过文献就连续旋转运动和往复式运动镍钛器械在根管成形能力、推出根尖孔的碎屑量、牙本质微裂及裂纹形成以及抗疲劳性能等方面的不同作一比较分析。     

新型往复运动单支锉根管预备对牙本质微裂的影响

目的 ：比较新一代往复运动单支锉WaveOne Gold和Reciproc Blue与上一代WaveOne和Reciproc在根管预备后产生牙本质微裂的差异。方法：将90颗离体下颌单根前磨牙随机分为6组（n=15）,分别为手用K锉组、WaveOne组、Reciproc组、WaveOne Gold组、Reciproc Blue组和空白对照组。将实验组根管预备至25#,空白对照组不作预备。利用硬组织切片机在距根尖孔3、6和9 mm处水平切割牙根,体视显微镜下放大25倍,观察不同横截面牙本质微裂情况。采用SPSS 17.0软件包对数据进行统计学分析。结果：手用K锉组和空白对照组未发现牙本质微裂;实验组中,WaveOne、WaveOne Gold、Reciproc和Reciproc Blue在根管预备后均产生了牙本质微裂,其中,WaveOne和手用K锉组产生的牙本质微裂纹数目差异有统计学意义（P<0.05）,裂纹主要集中于根管根中段;Reciproc和Reciproc Blue 2种往复运动单支锉造成的牙本质微裂数目相同,与对照组相比无统计学差异。结论：使用新一代往复运动单支锉WaveO...     

镍钛器械对椭圆形根管预备效果的影响

椭圆形根管具有特殊的解剖学形态,使用镍钛器械预备根管时在追求良好的成形能力同时,也会有不良的影响。目前几种常用的镍钛器械中,既有较高牙本质切削效率的优势也有形成牙本质微裂的风险;虽然镍钛器械代代更新,但是目前研究发现无论哪种器械对于椭圆形根管预备均具有一定的缺陷。本文将从镍钛系统对椭圆形根管的成形能力,包括切削能力、保持原有根管形态的能力以及不良影响如推出根尖孔碎屑量、形成牙本质微裂的影响两个大方面进行综述,为选择合适的镍钛器械预备椭圆形根管提供依据。     

四种机用镍钛系统根管预备后牙本质微裂比较研究

目的    通过比较4种机用镍钛系统体外预备根管后产生牙本质微裂的差异,为临床医生选择根管预备器械和方法提供参考。方法    选取2016年1—10月在中国医科大学附属口腔医院、鞍钢集团总医院口腔科及中国医科大学附属第一医院鞍山医院口腔科门诊拔除的新鲜完整下颌切牙为研究对象,按统一标准选择125颗样本制作研究模型,采用随机号码表法将样本平均分为5组,4个预备组分别应用机用ProTaper Next（N组）、WaveOne Gold（W组）、M3-Pro（M组）、ProTaper Universal（P组）进行根管预备,余下一组作为对照（C组）不进行根管预备。在距根尖3、6、9 mm处水平切割牙根,显微镜下观察记录各截面出现牙本质微裂情况,应用SPSS软件进行卡方检验。结果    未预备的C组没有发现牙本质微裂,P组产生微裂的牙数与N组、W组和M组分别对比均有显著增多,差异有统计学意义（P < 0.05）。所有预备组在距根尖3 mm处产生微裂的牙总数对比距根尖6 mm处和9 mm处有显著增多,差异有统计学意义（P < 0.05）。结论    应用机用镍钛器械进行根管预备可能造成牙本质微裂,在距根尖3 mm处产生的微裂要显著多于距根尖6 mm和9 mm处;相较ProTaper Universal,使用ProTaper Next、WaveOne Gold和M3-Pro可显著降低微裂的发生率。     

根管治疗中的顺滑通道制备及其临床意义

建立顺滑通道是根管预备成形的必要步骤，是安全有效预备根管的前提。文章介绍了顺滑通道的制备，并分别针对根管偏移和中心定位能力、根尖碎屑推出和术后疼痛、牙本质微裂形成、预备时间、根管器械分离等特性讨论了顺滑通道的临床意义。     

几种根管冲洗药物去除根管涂层的扫描电镜研究

用化学药物对根管冲洗消毒是根管预备的关键性步骤。在根管预备过程中会形成根管内涂层,即贴附于根管壁上的坏死组织、细菌以及扩锉产生的牙本质碎屑。机械扩预备并不能将涂层消除干净,必须使用能在根管内易于扩散和有利于封闭剂与牙本质密合的辅助化学药物冲洗以去之。本研究旨在用扫描电镜评价不同冲洗药物在化学和机械预备中的清洁效果。     

根管冲洗液对根管壁牙本质微硬度的影响

牙髓治疗中为获得清洁无菌的根管,要进行机械和化学预备。有研究表明,根管冲洗液对根管壁牙本质的机械、物理和化学性质均有影响。本实验的目的是评价不同冲洗液对根管壁牙本质微硬度的影响。 材料和方法 将18颗大小、形态相近的完整离体上切牙作为研究对象。从釉牙骨质界处截除牙冠,抽去牙髓,用K型锉按梯形预备法扩根管至50~#,根管冠部1/2用3~# Gates-Glidden牙钻扩开。将所有牙根随机     

镍钛器械预备根管对牙根抗折性影响研究进展

根管治疗术是牙髓病和根尖周病的首选和重要的治疗方法,治疗后常见并发症之一是牙根折裂。根管治疗术中的每一个步骤都有可能影响牙根的抗折性。根管预备因涉及牙本质的去除、根管形态结构的改变,更有可能危及牙根的抗折强度。近几年随着根管治疗技术的发展,镍钛器械已用于根管预备,镍钛器械一般锥度较大,预备出的根管有更好的冠部扩展,但牙本质壁变薄,会增加根管充填时发生根折的危险性。目前,针对镍钛扩根器械对牙体抗折性能的影响存在不同观点。本文就不同镍钛器械预备根管对牙根抗折性的影响做一综述。     

桩核对根管治疗牙修复后强度的影响

目的　比较不同修复方法对根管治疗牙修复后强度的影响。方法　 6 0个完整拔除的人上中切牙 ,根管治疗后随机分为 5组 ,每组 12个。A组 :完整的根管治疗牙 ;B组 :根管治疗后烤瓷熔附金属 (PFM)全冠修复 ;C组 :牙体预备保留 2 0mm高的牙本质套圈 ,铸造金属桩核及PFM全冠修复 ;D组 :牙体预备无牙本质套圈 ,铸造金属桩核及PFM全冠修复 ;E组 :牙体预备保留 2 0mm高的牙本质套圈 ,Parapost预成桩、复合树脂核及PFM全冠修复。在MTS 810材料试验机上沿与牙长轴成 135度方向加载 ,测试折裂强度。结果采用方差分析。结果　牙体预备保留 2 0mm高的牙本质套圈 ,铸造金属桩核及PFM全冠修复者折裂强度最高 ,为 (1793 5 9± 387 93)N ;完整的根管治疗牙次之 ,为(146 6 6 8± 2 40 11)N ;其余 3组的折裂强度 (95 8 49± 2 86 0 2 )N、(992 98± 2 91 0 0 )N、(994 94± 2 85 0 4)N之间 ,差异无显著性。修复牙有无牙本质套圈 ,其折裂强度间差异有高度显著性 (P <0 0 1)。结论　桩核能否增强根管治疗牙的抗折裂强度与其修复设计有关 ,牙本质套圈可明显增强根管治疗牙的抗折裂能力。     

Impact of Minimally Invasive Endodontic Procedures on the Development of Dentinal Microcracks

IntroductionTo evaluate the impact of root canal preparation in teeth with ultraconservative access cavities (UltraAC) on the development of dentinal microcracks using a nondestructive longitudinal micro–computed tomography (micro-CT) imaging experimental model. Root canal preparation in teeth with traditional access cavities (TradAC) was used as control.MethodsForty mandibular molars were scanned in a micro-CT device, anatomically matched, and distributed into 4 groups according to the type of access cavity and instrumentation system: traditional/Reciproc (TradAC/RC), traditional/XP-endo Shaper (TradAC/XP), ultraconservative/Reciproc (UltraAC/RC), and ultraconservative/XP-endo Shaper (UltraAC/XP). After root canal preparation, the teeth were rescanned. After reconstruction and co-registration procedures, the images were screened from the furcation level to the apex to identify the presence of dentinal microcracks.ResultsFrom a total of 15,340 cross-section images, 19.65% (3014 slices) had some dentinal microcracks. The qualitative analysis demonstrated the presence of some dentinal microcracks in 11%, 33%, 19%, and 15% of the images of cross-sections in TradAC/RC, TradAC/XP, UltraAC/RC, and UltraAC/XP groups, respectively. All dentinal microcracks observed after root canal preparation were already present in the corresponding images before canal instrumentation. Therefore, no new microcracks were detected, regardless of the access cavity and root canal instrumentation system.ConclusionsRoot canal preparation with Reciproc or XP-endo Shaper under traditional or ultraconservative access cavities did not create dentinal microcracks in extracted mandibular molars.     

Incidence of microcracks after preparation of straight and curved root canals with three different NiTi instrumentation techniques assessed by micro‐CT

This study evaluated the effect of three different NiTi instrumentation techniques on the incidence of microcracks after the preparation of straight and curved root canals using micro‐CT. Roots from mandibular premolars and maxillary molars (n = 66) with the same mean canal curvatures were assigned to three groups of straight and three groups of curved roots (n = 11). After preoperative micro‐CT scans, root canals were prepared with Reciproc, OneShape and ProTaper Next to size 25. Specimens were scanned again, and pre‐ and post‐operative cross‐sectional images (n = 75 263) were screened to identify the presence of dentinal microcracks. Overall, microcracks were detected in 2.97% (n = 2236) of the cross‐sectional images. No new dentinal microcracks were observed after root canal instrumentation of straight and curved canals with the tested NiTi systems. Instrumentation with Reciproc, OneShape and ProTaper Next did not induce the formation of dentinal microcracks irrespective of canal curvature.     

Root Canal Preparation Does Not Induce Dentinal Microcracks In Vivo

IntroductionThis in vivo study aimed to evaluate the development of dentinal microcracks after root canal preparation of contralateral premolars with rotary or hand instruments using micro–computed tomographic technology.MethodsSixty contralateral intact maxillary and mandibular premolars in which extraction was indicated for orthodontic purposes were selected and distributed into positive (n = 6, teeth with induced root microcracks) and negative (n = 6, intact teeth) control groups as well as 2 experimental groups (n = 24) according to the instrumentation protocol: ProTaper rotary (PTR) or ProTaper hand (PTH) systems (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparation, teeth were extracted using an atraumatic technique and scanned at a resolution of 17.18 μm. A total of 43,361 cross-sectional images of the roots were screened for the presence of dentinal microcracks. The results were expressed as the percentage and number of root section images with microcracks for each group.ResultsAll roots in the positive control group showed microcracks at the apical third, whereas no cracks were observed in the specimens of the negative control group. In the PTR group, 17,114 cross-sectional images were analyzed, and no microcrack was observed. In the PTH group, dentinal microcracks were observed in 116 of 17,408 cross-sectional slices (0.66%) of only 1 specimen. These incomplete microcracks extended from the external root surface into the inner root dentin at the area of reduced dentin thickness.ConclusionsRoot canal instrumentation with PTR and PTH instruments of contralateral maxillary and mandibular premolars did not result in the formation of dentinal microcracks in vivo.     

Micro–computed Tomographic Evaluation of Dentinal Microcracks after Preparation of Curved Root Canals with ProTaper Gold,WaveOne Gold,and ProTaper Next Instruments

IntroductionThe aim of this study was to evaluate the influence of rotary (ProTaper Next [PTN; Dentsply Maillefer, Ballaigues, Switzerland] and ProTaper Gold [PTG, Dentsply Maillefer]) and reciprocating (WaveOne Gold [WOG, Dentsply Maillefer]) systems in dentinal microcrack generation after the preparation of curved root canals using micro–computed tomographic analysis.MethodsTwenty-four human mandibular molars with curved roots were scanned in a micro–computed tomographic device using an isotropic resolution of 6.78 μm and randomly assigned into 1 of 3 experimental groups (n = 8) according to the root canal instrumentation system used (PTN, PTG, or WOG). Then, the root canals were prepared up to PTN X2, PTG F2, and WOG Primary instruments in the PTN, PTG, and WOG groups, respectively. After canal preparation, each specimen was scanned again. Pre- and postoperative cross-sectional images of the roots (N = 35,304) were analyzed to identify the presence of dentinal microcracks.ResultsOverall, 26% of the images presented dentinal defects (n = 9188). Dentinal microcracks were observed in 24.6%, 26%, and 27.4% of the postinstrumentation images from the PTN, PTG, and WOG groups, respectively. However, all of these dentinal microcracks were already present in the corresponding preoperative images. No new microcracks were generated after the preparation of curved root canals of mandibular molars using the aforementioned systems.ConclusionsRoot canal instrumentation with PTN, PTG, and WOG systems did not induce the formation of new dentinal microcracks.     

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??Nickel-titanium instruments are the mainstream in the root canal preparation??and are widely used in the modern root canal treatment. But some researchers believe that the preparation process may cause or aggravate dentinal microcracks of the root canal wall. Dentinal microcracks will lead to bacteria colonization??microleakage and even vertical root fracture??and reduce the long-term outcome of root canal treatment. This article elaborated the hazard??etiology??prevention and controversy of the formation of dentinal microcracks in the process of root canal preparation with nickel-titanium instruments.     

Er∶YAG激光在根管治疗中的应用研究进展

由于根管系统的复杂性,传统的根管预备器械与冲洗剂难以达到完全清理根管的目的。Er∶YAG激光联合根管冲洗剂使用,既可以采取更保守的根管预备,又能增强去除玷污层、开放牙本质小管和杀菌的能力,有利于根管封闭剂和根管内黏结剂的渗透而减少微渗漏;且在一定的激光参数范围内,其不会引起冲洗剂的根尖渗出;产热作用也极小,不会引起根尖周组织损伤。因此,Er∶YAG激光的应用能使根管预备过程变得简单、高效、安全。本文综述了Er∶YAG激光在根管治疗中的应用研究进展。     

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由于根管系统的复杂性。传统的根管预备器械与冲洗剂难以达到完全清理根管的目的。Er：YAG激光联合根管冲洗剂使用,既可以采取更保守的根管预备,又能增强去除玷污层、开放牙本质小管和杀菌的能力,有利于根管封闭剂和根管内黏结剂的渗透而减少微渗漏;且在一定的激光参数范围内,其不会引起冲洗剂的根尖渗出;产热作用也极小,不会引起根尖周组织损伤。因此,Er：YAG激光的应用能使根管预备过程变得简单、高效、安全。本文综述了Er：YAG激光在根管治疗中的应用研究进展。     

Comparative Evaluation of Dentinal Microcrack Formation before and after Root Canal Preparation Using Rotary,Reciprocating, and Adaptive Instruments at Different Working Lengths—A Micro–computed Tomographic Study

IntroductionThis study aimed to compare root dentinal microcrack formation after root canal shaping using rotary, reciprocating, and adaptive instruments at different working lengths using micro–computed tomographic imaging.MethodsOne hundred eighty extracted mature mandibular molar mesial roots with 2 separate canals were selected. The mesial roots were resected at the cementoenamel junction and randomly divided into 4 groups (n = 45) based on the nickel-titanium file system used: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Gold (Dentsply Maillefer), Twisted File Adaptive (SybronEndo, Orange, CA), and Reciproc Blue (VDW, Munich, Germany). Each of the 4 groups were then subdivided into 3 groups (n = 15) depending on the working length used for root canal preparation (ie, instrumentation 1 mm short, flush, and 1 mm beyond the major apical foramen). The roots were imaged with micro–computed tomographic scanning before and after root canal preparation. The cross-sectional images generated were screened to detect the presence of new microcracks.ResultsThe ProTaper Universal system significantly increased the number of postinstrumentation microcracks at all working lengths (P ≤ .05). No significant increase (P > .05) in postinstrumentation microcracks was observed in the ProTaper Gold, Twisted File Adaptive, or Reciproc Blue groups.ConclusionsRotary instrumentation induced a higher number of dentinal microcracks compared with reciprocating and adaptive instruments. Instrumentation at different working lengths did not significantly influence the formation of dentinal microcracks.     

Micro–computed Tomographic Evaluation of Dentinal Microcrack Formation after Using New Heat-treated Nickel-titanium Systems

Introduction

The aim of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with HyFlex CM (Coltène/Whaledent, Altstätten, Switzerland), HyFlex EDM (Coltène/Whaledent), Vortex Blue (Dentsply Tulsa Dental Specialties, Tulsa, OK), and TRUShape (Dentsply Tulsa Dental Specialties) systems using micro–computed tomographic (micro-CT) analysis.

声波器械去除根管玷污层能力的比较研究

目的:比较声波、超声波和手用器械去除根管玷污层能力。方法:收集离体单根管的前磨牙40个,随机分为4组,分别由声波器械、超声波器械、手用器械以及声波和手用器械联合行根管预备,应用扫描电镜进行观察,采用Wilcoxon秩和检验进行统计学分析,根据根管表面的玷污层的量和牙本质碎屑比较声波器械去除根管玷污层的能力。结果:根尖1/3部分,在去除玷污层方面,声波器械组、超声波器械组以及声波器械和手用器械联合组,与手用器械组之间有显著性差异(P<0.05);在去除牙本质碎屑方面,超声波器械组与手用器械组之间亦有显著性差异(P<0.05),声波器械组以及声波器械和手用器械联合组与手用器械组之间有非常显著性差异(P<0.01)。声波器械组以及声波器械和手用器械联合组,与超声波器械组在去除玷污层和牙本质碎屑方面无显著性差异(P>0.05)。根中1/3和根上1/3部分,各组间比较均无显著性差异(P>0.05)。结论:根尖1/3根管预备,声波器械去除玷污层和牙本质碎屑的能力优于手用器械,尤其是去除牙本质碎屑的能力更强;与超声波器械近似。