Root ZX根尖定位仪在隐裂牙治疗中的应用效果评价

目的:评价分析Root ZX根尖定位仪在隐裂牙治疗中的临床效果.方法:将384颗隐裂导致牙髓病变的患牙平均分两组,实验组Root ZX根尖定位仪电测法测量根管工作长度,完成根备,充填,对照组用X线片法测量根管工作长度,其余治疗与实验组相同.结果:两组根管充填术后疼痛率分别为8.9%和13.0%,根管充填实验组适填率为89.1%,差填或超填率为10.9%,而对照组分别为90.1%、9.9%.以上结果两组间差异均无统计学意义(P ＞ 0.05).结论:Root ZX根尖定位仪电测法测定隐裂牙根管工作长度准确性高,临床效果好.     

根管长度电测仪用于乳牙根管长度测量的体外实验

目的探讨根管长度电测仪用于根尖有无生理性吸收的乳牙根管长度测量的准确性。方法选取40颗离体乳前牙,根据根尖区有无吸收情况分为两组,分别置于体外模型中,用RootZX根管长度电测仪测量其工作长度,将其与在5倍放大镜下测量出的真正结果相比较。结果在±0.5mm范围内,根尖有吸收组电测长度准确率为85.00%,无吸收组为90.00%。虽然测量值较真实值略低,但两者差异无统计学意义（χ2=0.23,P〉0.05）。结论体外测量结果表明,乳牙根尖生理性吸收的存在不会影响电测法的准确性。     

临床根管工作长度的测定

目的 :探讨根尖X线片法、痛感法和电测法在根管工作长度测量中的可靠性。方法 :随机从临床收治病人中 ,选择前牙根管可扩通的 6 5例病人 ,10 5个根管 ,分别用上述三种方法测量根管工作长度 ,并与根管插牙胶尖所测根管工作长度进行比较。结果 :电测法的准确率 :93.3% ;痛感法准确率 2 8.6 % ;常规根尖X片准确率 14 .3%。结论 :常规根尖X线片和痛感法只能作为测量根管工作长度的辅助方法 ,电测法准确性高 ;牙髓状况、根尖周病变范围和根管渗出对电测法影响不大     

电子根尖测定仪测定根管工作长度准确性评价

目的:评价电子根尖测定仪测定根管工作长度的准确性.方法:行根管治疗牙髓炎、尖周炎患者166例(166牙),应用电子根尖测定仪测定根管工作长度,并与X线诊断丝照相法确定的工作长度进行比较.结果:电子根尖测定仪测定根管工作长度符合率90.27%.结论:电子根尖测定仪可较准确测量根管工作长度.     

RayPex5根管测量仪测量根管工作长度准确性的临床分析比较

目的通过对RayPex5电测法与根管器械探测手感法测量根管工作长度的准确率进行比较,以此评价RayPex5根管测量仪在临床操作中应用的准确性。方法选择门诊需要进行根管治疗的86例患者108颗患牙,196根根管,在测量根管工作长度时分别应用RavPex5和手感法测量,按测量长度预备根管后再插入主牙胶尖试尖摄x线牙片来检验两种不同方法的准确性。结果RayPex5~O量组根管工作长度的准确率94．9％;手感法测量组根管工作长度的准确率71．9％;两组差异具有统计学意义（P〈0．01）。结论RayPex5根管测量仪是利用根尖孔牙周膜至口腔黏膜间的直流电流电阻值是恒定的原理而设计的,可以准确定位生理性根尖孔,简单易行,弥补了手感法测量误差,大大提高了根管测量的准确性。     

RootZX电子根管长度测量仪的临床应用

目的 :评价RootZX电子根管长度测量仪测量根管工作长度的准确性。方法 :选取门诊患者 80例 13 1个根管随机分成两组 ,试验组 42例 72个根管 ,对照组 3 8例 5 9个根管 ,分别用RootZX电子根管长度测量仪和诊断丝X线片法确定工作长度 ,并以各自的工作长度进行根管预备和充填 ,拍X线片 ,测量根管充填材料至根尖的距离。结果 :按两种方法测得长度充填根管X线片结果有显著性差异 (P <0 0 0 5 ) ,RootZX电子根管长度测量仪准确率达到 90 2 8% ,而对照组只达到 77 97%。结论 :RootZX电子根管长度测量仪能准确、快速的测量出根管长度 ,根管充填效果好 ,临床疗效好。     

牙齿根管长度测量仪准确性影响因素的研究现状

牙髓病与根尖周病是口腔内科常见疾病,根管治疗是目前公认的治疗方式［1］。根管治疗中根管工作长度（根尖狭窄处距离参考点的距离）的准确测量,能够在根管预备过程中加强对根管内感染物的清除,也可以防止操作器械穿出根尖狭窄区而损伤根尖周组织,根尖狭窄是公认的根充止点,把握好根管工作长度能够在根管充填时提高恰填率［2］,对其疗效及预后有重要意义。目前根管工作长度测定的方法主要有手感法、冠根比例法、X线辅助计算法以及通过根管长度测量仪测定法,根管长度测量仪测量的准确性最高,且应用简单方便。本文对根管长度测量仪准确性及影响因素的相关文献做一归纳总结。     

机用 ProTaper 器械预备磨牙重度弯曲根管对根管工作长度的影响

目的：观察机用 ProTaper 器械预备磨牙重度弯曲根管对根管工作长度的影响。方法选择磨牙根管弯曲度在25＆#176;~45＆#176;的牙髓炎、根尖炎患者307颗牙386个重度弯曲根管,随机分为对照组和实验组,对照组151颗磨牙186个根管使用 GG 钻联合手用不锈钢 K 锉采用逐步后退法预备根管,分别测量预备前、后根管长度;实验组156颗牙200个根管使用机用 ProTaper 器械预备根管,分别测量预备前和 SX、S1、S2、F1、F2、F3预备后根管长度,将数据进行统计学分析。结果对照组和实验组组预备前后根管长度变化比较,差异有统计学意义（ t ＝14.28,P 〈0.01）,实验组内 SX、S1、S2、F1、F2、F3预备后根管长度变化差异无统计学意义（P 〉0.05）。结论机用 ProTaper 器械预备磨牙重度弯曲根管后对根管工作长度影响小,根管预备效果好。     

两种根管预备方法临床效果比较

目的比较机用镍钛根管扩大锉profile与手用不锈钢扩大锉K—file两种根管预备方法的临床效果。方法两组后牙根管分别用机用镍钛扩大锉profile、手用不锈钢扩大锉k-file进行预备，比较术后充填和疼痛情况。结果机用镍钛根管扩大锉profile比手用根管扩大锉k-file省时省力，去除感染组织较彻底，术后疼痛小，但在较弯曲根尖段易折断。结论利用两种方法的优缺点互补，可增加工作效率，减少并发症。     

次氯酸钠冲洗对RootZX电子根管长度测量仪精确度的影响

目的 :测定次氯酸钠冲洗根管是否影响RootZX测量仪的精确性。方法 :3 0颗离体牙 ,分别采用不同冲洗方法和测量方法测量计数。A组 :生理盐水冲洗根管。B组 :2 12 5 %次氯酸钠冲洗根管。C组 :5 2 5 %次氯酸钠冲洗根管 ,三组分别用RootZX测量仪测量工作长度。D组 :测量锉尖刚露出根尖孔的长度为实际根管长度 (直接观察 ) ,最后分别用A、B、C组数值减去D组数值获得三组数值。结果 :三组间没有统计学差异 ,RootZX测量精确度在± 0 5mm以内为 81 6%。结论 :RootZX测量仪精确度不受次氯酸钠冲洗液的影响。     

上颌第一前磨牙根管形态和根尖孔的解剖研究

目的 研究上颌第一前磨牙根尖孔的分布和根管形态.方法 100个上颌第一前磨牙牙颈部片切后观察根管口、根尖孔的位置并测量根尖孔与根尖顶的距离,然后制成透明牙,观察其根管形态.结果 上颌第一前磨牙根尖孔位于根尖部为57.8%,非根尖部为42.2%,根尖孔距根尖的平均距离为0.62 mm,根管类型1-1-1型占8%,2-2-2型占56%,单双混合型36%.结论 上颌第一前磨牙根管形态复杂多变,根尖孔不在根尖部具有较高的比率.     

Study on apical leakage of the teeth after argon laser treatment and obturation

OBJECTIVE: This study was performed to compare the apical leakage degree after laser treatment and obturation with that without laser treatment, and to evaluate the efficiency of argon laser irradiation in removing debris and smear layer from the prepared root canal walls in vitro. SUMMARY BACKGROUND DATA: There has been no report of laser effect on apical leakage after laser treatment and obturation. METHODS: Fifty-six human extracted single root teeth were used in this study. Teeth were divided into four groups of 14 teeth each and prepared up to a #60 K-file size at 1 mm short of the apical foramen using a step-back technique. Argon laser at the wavelength of 470 nm and at the output of 0.3 W was irradiated at apical stop for 1, 2, or 3 seconds at the continuous mode. In each group, ten teeth for the microleakage study were obturated and immersed in rhodamine B solution for 48 hours at 37 degrees C, and the others were used for the observation by scanning electron microscopy (SEM). All teeth were bisected longitudinally and observed by stereoscopy or SEM. RESULTS: The apical leakage degree after laser treatment and obturation was reduced compared to that in the control, but not significantly (p > 0.05). However, debris and smear layer in the laser-treated groups were removed from apical stop even at low energy density. CONCLUSIONS: These results suggest that apical leakage after argon laser treatment is not reduced significantly, but that argon laser is useful for removing debris and smear layer from root canals.     

Vitapex诱导实验性根尖周炎小鼠血清中TNF-α和TGF-β1的表达分析

目的分析Vitapex诱导鼠实验性根尖周炎中肿瘤坏死因子α(TNF-α)和转化生长因子-β1(TGF-β1)的表达。方法 24只SPF级C57BL/6小鼠随机平分为三组:模型组、Vitapex组、对照组。模型组、Vitapex组小鼠均建立实验性根尖周炎模型,对照组小鼠不进行处理,建模后3周Vitapex组小鼠同时进行Vitapex处理3周。术后3周与术后6周检测各组小鼠TNF-α和TGF-β1表达情况。术后3周与术后6周拍摄所有小鼠的牙根尖X线片,测量与计算牙根长度增加值与管壁厚度增加值。记录三组小鼠术后6周根尖孔闭合、根管壁新组织形成、根内牙髓样组织形成等发生率。结果模型组、Vitapex组术后3周与术后6周的血TNF-α和TGF-β1表达水平都显著高于对照组(P<0.05),且与术后3周相比,两组术后6周TNF-α水平显著降低,TGF-β1水平显著升高(P<0.05);术后Vitapex组TNF-α的表达水平低于模型组,TGF-β1表达水平显著高于模型组(P<0.05)。术后6周,模型组牙根长度增加值、管壁厚度增加值、根尖孔闭合、根管壁新组织形成、根内牙髓样组织形成等发生率均显著低于对照组(P<0.05),而Vitapex组的牙根长度增加值、管壁厚度增加值、根尖孔闭合、根管壁新组织形成、根内牙髓样组织形成等发生率均显著高于模型组,差异均有统计学意义(P<0.05)。结论 Vitapex在诱导鼠实验性根尖周炎中的应用能抑制TNF-α的表达,并促进牙根尖组织中TGF-β1的分泌,可促进根管壁增厚和根尖孔闭合,也促进形成新的牙骨质样和牙髓样组织。     

Separated root tip formation associated with a fractured tubercle of dens evaginatus: A case report

BACKGROUNDSeveral previous studies have reported an unusual root formation in which a fractured apical fragment of an immature root continued to develop independent of the main root after trauma to an immature tooth. To date, there have been only rare reports of the continuing apical formation of the fractured root associated with dens evaginatus (DE). This paper presents a case of a separated root tip formation associated with a fractured tubercle of DE.CASE SUMMARYAn 11-year-old boy was referred for gingival sinus on the buccal side of the right mandibular second premolar (tooth # 45). Clinically, tooth # 45 was free of caries, but there was a sign of a fractured tubercle of DE on the occlusal surface. Radiography showed that the root canal of tooth # 45 was widely radiolucent. A separated root apex was found apically under the main root and was nearly completely formed with an apical orifice at the apical tip. Tooth # 45 was diagnosed as tubular fracture of DE with chronic apical periodontitis. A revascularization technique was recommended to treat the tooth. At 3-mo and 1-yr follow-up, the patient remained asymptomatic. Periapical radiography revealed that the separated root tip distally drifted with closure of the apex. However, the root length and thickness of the main root did not increased. CONCLUSIONClinicians should be aware that even if tubercle of DE is fractured in an immature tooth, the root tip may be separated from the main root and completely formed.     

Errors as a result of metal in the near environment when using an electromagnetic locator with freehand three-dimensional echocardiography.

BACKGROUND: Quantitative ventriculography by freehand 3-dimensional (3D) echocardiography with an acoustic spatial locator has been proven to provide highly accurate reproducible measurements of left ventricular volume, mass, and function. It has been shown to be 2 to 3 times better than conventional 2-dimensional echocardiographic techniques. Although accurate, the acoustic spatial locator uses a spark gap to generate hypersound for locating and is somewhat bulky. The Bird direct current electromagnetic locator (Ascension Technology Corp, Burlington, Vt) is a notable alternative locator for the freehand 3D system because it is small and easily portable. However, conductive metals in the near environment may adversely affect electromagnetic locator accuracy. To determine the feasibility of using the electromagnetic locator in a freehand 3D echocardiographic system in the conventional hospital environment, a series of experiments was carried out assessing the accuracy of such a system under various conditions of exposure to conductive metal. METHODS: Using tissue equivalent ellipsoid phantoms of known volumes, we compared volume measurement accuracy of the freehand 3D echocardiographic system equipped with the standard Bird or miniBird electromagnetic locator systems with our freehand acoustic spatial locator 3D echocardiographic system in 3 experiments: (experiment 1) no metal within 30 in (76.2 cm) of the phantoms and electromagnetic locator; (experiment 2) phantoms placed on a standard metal hospital stretcher with conductive metal less than 10 in (25.4 cm) from the phantoms and electromagnetic locator and with the echocardiographic machine greater than 30 in (76.2 cm) from the electromagnetic locator; and (experiment 3) phantoms placed on the same stretcher with conductive metal less than 10 in (25.4 cm) from the phantoms and electromagnetic locator and with the echocardiographic machine in its usual position approximately 10 in (25.4 cm) from the electromagnetic locator. RESULTS: For experiment 1 there was no significant volume error (<1%) by any system; no significant difference among the 3 locator systems (acoustic, Bird, or miniBird). For experiment 2 there was significant volume underestimation error by both electromagnetic locator systems (-10.9%, P <.05). For experiment 3 there was significant and greater volume underestimation error by both electromagnetic locator systems (-14.7%, P <.05) in close proximity to the echocardiographic machine. Interobserver variability was 5.1%. CONCLUSION: For quantitative ventriculography by a freehand 3D echocardiographic system, electromagnetic locator systems should not be used if conductive metal is in the near environment (<30 in [76.2 cm] from the locator). Accurate quantitative ventriculography may be performed with an electromagnetic locator system if the near environment is free of conductive metals.     

迷走神经阻滞入路的相关解剖结构研究

目的：对迷走神经阻滞入路相关结构及其毗邻关系进行解剖学观测,为迷走神经阻滞入路和预防并发症的发生提供解剖学基础。方法：对60个成人颅骨（120侧,其中男60侧,女60侧）和30侧成人头、颈部标本迷走神经的毗邻结构进行解剖学观测。结果：迷走神经阻滞进针的深度（乳突尖至颈静脉孔外侧缘的距离）：男性左侧为24.5±0.5mm(17.0—30.2mm),右侧为24.9±0.7mm(19.5—30.4mm);女性左侧为23.1±0.4mm(16.0—28.5mm),右侧为22.7±0.6mm(13.0—28.3mm)。观测获得了乳突尖至茎乳孔的距离,茎乳孔至颈静脉窝外侧缘的距离。颈静脉孔的变异情况,迷走神经在颈静脉孔内、外与其他结构的关系。结论：可以乳突为标志作为预测颈静脉孔位置深度的参考数据。穿刺时,应注意避免误伤面神经和颈内静脉。     

Effects of Nd:YAG and Er:YAG lasers on the sealing of root canal fillings

OBJECTIVE: The ability of the laser irradiation to promote the cleaning and disinfection of the radicular canal system has become this type of treatment in a viable and real alternative in endodontics. The purpose of this study was to evaluate the apical marginal sealing of root canal fillings after the irradiation with the laser of Nd:YAG or of Er:YAG. MATERIALS AND METHODS: Forty-two human, extracted single-rooted teeth had their crowns sectioned and the root canals prepared with a no. 70 K-file. Then, they were dried and divided into three groups according to canal wall treatment: group 1: the canals were filled with EDTA for 3 min, followed by irrigation with 1% sodium hypochlorite solution; group 2: the canal walls were irradiated with Nd:YAG laser; and group 3: the canal walls were irradiated with Er:YAG laser. Afterwards, the root canals were obturated by the lateral condensation technique. The roots were externally waterproof, except in the apical foramen and immersed in 2% methylene blue aqueous solution during 48 hours. RESULTS: The results showed that the largest infiltrations happened in the group 3-Er:YAG (7.3 mm), proceeded by the group 1-EDTA (1.6 mm) and by the group 2-Nd:YAG (0.6 mm). The group Er:YAG differed statistically of the others (p < 0.05). CONCLUSION: It was concluded that the Er:YAG laser intracanal irradiation previously to the root canal filling must be used with caution until future research is define the best parameters for it's use.     

斑点追踪显像技术评价正常婴幼儿、儿童及青少年收缩期左心室各节段室壁旋转运动

目的 应用超声二维斑点追踪显像技术探讨正常婴幼儿、儿童及青少年左心室各节段室壁扭转运动特征.方法 将117名3天～15岁健康受试者按年龄分为5组:婴幼儿组(3天～2岁),学龄前期组(3～5岁),学龄期组(6～9岁),青春前期组(10～12岁),青春期组(13～15岁).取胸骨旁左心室心尖和心底短轴切面对左心室扭转进行测量,分析各节段室壁旋转角度及心尖水平、心底水平的旋转角度,计算左心室整体扭转角度(Ptw),比较各组参数的差异. 结果①正常婴幼儿、儿童及青少年左心室扭转运动主要表现为心底部顺时针旋转和心尖部逆时针旋转.②在同一年龄组,心底水平各节段室壁旋转角度从前壁逐渐递增(前壁<前间隔<侧壁<后间隔<后壁<下壁)(P<0.05), 不同年龄组心底水平各节段间室壁旋转角度差异无统计学意义.③心尖水平各节段室壁旋转角度随年龄增加而变化,在青春期达到最高(P<0.05),而相同年龄组心尖水平各节段旋转角度差异无统计学意义.④同一节段室壁心尖水平与心底水平旋转角度随着年龄增长,逐渐以心尖水平的旋转为主,到青春期心尖水平与相应节段的心底水平室壁相比差异有统计学意义(P<0.01).⑤心底水平左心室旋转角度随年龄增加而变化,但差异无统计学意义,心尖水平左心室旋转角度随年龄增加而增加(P<0.05);左心室整体扭转则随年龄增加而增加,在青春前期及青春期达到最大(P<0.05).⑥不同性别儿童的旋转及扭转各参数的差异无统计学意义. 结论 在出生后至青春期随着心脏的发育,左心室心肌各节段室壁心尖水平旋转和整体扭转随年龄增加而增强.     

右心室心尖不同部位起搏时左心室收缩时序的超声研究

目的探讨右心室心尖不同部位起搏时左心节段性室壁的收缩特征及时序。方法利用实时三维超声心动图技术确定右心室心尖起搏电极顶端在右心室心尖部的准确空间附着位点。运用应变显像技术，测定左心室壁各节段收缩期应力的达峰时间，即自心电图Q波起点至收缩期峰值应变时限（interval between Q wave of surface ECG and peak strain，QPSI），反映左心室各室壁的收缩时序；并计算QPSI的离散度，即最大QPSI减去最小QPSI的时限差，代表左心室内收缩延迟时间。观察正常对照组、右心室心尖不同部位起搏组左心室壁的节段性运动，评价各组左心室壁的收缩（或应变）时序及收缩协调性。结果右心室心尖起搏组的左心室壁收缩时序较正常对照组发生改变。右心室心尖侧壁起搏与右心室心尖间隔起搏组的左心室壁收缩时序不同，左室间隔心尖段、后壁基底段差异存在统计学意义（P〈0．05）。右心室心尖起搏时左室壁整体的收缩发生延迟，并且右心室心尖侧壁起搏组左室壁的收缩延迟时间明显大于右心室心尖间隔起搏组（P〈0．05）。结论右心室心尖不同部位起搏可以导致左心室不同的收缩模式改变，提示右心室心尖不同部位起搏所引起的电激动顺序及对心脏血流动力学的影响也存在差异。