【作者】 雷月娟；

【导师】 何克新；

【作者基本信息】 广西医科大学 ， 口腔内科学， 2007， 硕士

【摘要】 目的通过比较用ROOT ZX(SM-RCM-1根管长度测定器)测量活体牙的根管工作长度和拔除该牙后直接测量该牙的实际工作长度,分析ROOTZX在多种临床条件下测量的准确度和临床因素对测量准确度的影响及各因素间的相互作用,指导临床实践,提高临床治疗效果。材料和方法收集2006年9月至2006年11月在广西医科大学附属口腔医院口腔颌面外科门诊就诊的因正畸、牙周疾病、鼻咽癌放疗前及义齿修复需拔除的患牙,包括活髓牙、死髓牙、单根管牙和多根管牙。在体内,拔牙前先开髓、拔髓、1-3号G型钻预备根管冠部、生理盐水冲洗根管,ROOT ZX根管长度测定器分别测量根管在干和湿状态时、用8号和能达到根尖孔的最大号不锈钢K锉插入根管,屏幕显示到达Apex位点(相当于根尖孔)和0.5位点(相当于根尖狭窄)的根管工作长度。ROOT ZX的测量值称为电测量长度(electronic measuring length,EML),简称电测值。然后将患牙完整拔出,消毒处理。在体外,将能到达根尖孔的最大号测量锉插入根管,在(10×)解剖显微镜下观测锉尖到达根尖孔时,调整橡胶标志到牙冠参照点,取出测量锉,数显深度卡尺测量橡胶标志到锉尖的距离,即为牙冠参照点到根尖孔(major foramen,MAF)的距离;然后,再将测量锉插入根管,沿根管方向磨去根尖段约4mm长的一侧牙体组织,当接近根管隐约可见测量锉时,换慢速单面金刚砂片很小心地磨除剩余牙体组织,暴露根管,在(10×)解剖显微镜下观测锉尖到达根尖狭窄时,调整橡胶标志到牙冠参照点,取出测量锉,数显深度卡尺测量橡胶标志到锉尖的距离,即为牙冠参照点到根尖狭窄(minor foramen,MIF)的距离。参照点分别到根尖孔和根尖狭窄的距离称为离体牙实际测量长度(actual length,AL),简称实测值。选择统计软件包SPSS13.0,为了避免由于牙齿长度差异引起的误差,用样本均数(即电测值和实测值差值均数)和总体均数(0)比较方法分析电测值和实测值之间的差异;用多因素析因设计的方差分析方法,分析临床因素(活/死髓、单/多根管、8号/最大号锉、根管干/湿状态)对ROOT ZX测定根尖孔和根尖狭窄准确度的影响及各因素间的相互作用;检验水准α=0.05。测定前,告知患者实验内容,经患者/监护人同意,并严格遵循《赫尔辛基宣言》的协定。结果1.一般资料:收集49颗牙,其中单根管牙36颗,多根管牙13颗,活髓牙40颗,死髓牙9颗;共计64个根管,其中5个根管拔牙时折断,9个根管因根尖欠通未能测量,50个能测量的根管。2.ROOT ZX测量到达根尖孔和根尖狭窄的电测值和实测值之间的差异无统计学意义(P＞0.05)。3.ROOT ZX测量准确度:测定根尖孔在±0.5mm,±1.0mm,±1.5mm范围内的准确率分别为75.65%,95.34%,100%;测定根尖狭窄在±0.5mm,±1.0mm,±1.5mm范围内的准确率分别为77.71%,98.09%,99.36%。4.多因素析因设计的方差分析结果显示:(1)活/死髓对ROOT ZX测量准确度的影响:F=5.037,P=0.025＜0.05,差异有统计学意义,但由于两者之间的差值很小(仅为0.08mm),没有临床意义。(2)其他因素,包括:单/多根管、8号/最大号锉、根管干/湿状态对ROOT ZX测量根尖孔和根尖狭窄准确度的影响:P＞0.05,差异无统计学意义。(3)这四个因素相互之间对ROOT ZX测量根尖孔和根尖狭窄准确度无交互影响作用:P＞0.05,差异无统计学意义。结论临床应用ROOT ZX根管长度测定器测量根管工作长度,对于根尖孔已发育完成的患牙,测定根尖孔和根尖狭窄的准确度高,不受根管数目、牙髓状态、根管干湿状态和测量锉大小的影响,对根管工作长度测量具有较好的辅助作用。更多还原

【Abstract】 Objective The purpose of this study was to determine the accuracy of the ROOT ZX apex locator under different clinical conditions,and try to find out the influent factors in order to guide clinical practice.Materials and Methods Teeth with mature root apices and planned for extraction because of orthodontics,periodontics,Nasopharyngeal carcinoma or prosthodontic reasons were used in this study.After obtaining the right access to the canals,The teeth were cut horizontally into a flat surface to obtain a stable and unequivocal reference for all measurements before the coronal portion of each canal was flared using number 1 to 3 Gates Glidden,and then irrigated with 0.9%sodium chloride,after that,according to the manufacturer’s instructions,a file was introduced in the canal until the signal on the screen reached the "apex" mark which indicated that the file tip arrived at the apical major foramen,a rubber stop was then carefully adjusted to the reference level and the distance between the rubber stop and the file tip was measured to the nearest 0.01mm with a digital caliper and recorded.Then the file was inserted into the root canal again until the signal flashed "Apex" and retracting the file until the display read 0.5mm which was the mark of apical constriction or the minor foramen,adjusted the rubber stop,measured and recorded.All canals were measured by using ROOT ZX apex locator under different size of stainless-steel K-files and different root canal humidity when the signal on the screen reached the "apex" mark and the "0.5"mark as described ahead.And the teeth were extracted and sterilized.The actual canal lengths from the crown reference to the major foramen were determined by placing a file into the canal until the tip of the file was just visible at the major apical foramen under a microscope at 10×magnification.With the file was inserted into the canal again,the apical 4-mm of each root was shaved using a finishing bur along the axis of the tooth until the file could be seen through a thin layer of dentin which was carefully removed to expose the canal under the microscope at 10×magnification.Then adjusted the rubber stop when the end of the file reached the minor foramen or the apical constriction,measured and recorded the actual canal length from the reference to the minor foramen.Informed consent was obtained by each patient.All patients were gathered from the department of oral and maxillofacial surgery in the Affiliated Stomatological Hospital of Guangxi Medical University during September to November in 2006.To eliminate any bias that would be contributed by a systematic error in ROOT ZX apex locator measurements related to uncontrolled variables(e.g,tooth length),the difference between Electronic measuring length(EML)and the Actual length(AL)was compared with using one-sample T test and the five-way analysis of.variance (ANOVA)was conducted to investigate the influence of vital/necrotic pulp, single-rooted/multi-rooted,small/large K-file and dry/wet canal on the measurement error in locating the major foramen and the minor foramen.P value was set at 0.05.Results 1.General data:49 teeth with mature apices and 64 root canals altogether were used in this study,among these teeth 36 were single-rooted and 13 were multi-rooted,40 were vital pulp and 9 were necrotic pulp,among the 64 canals,only 50 had measurements because 5 were fractured during extraction and 9 could not be measured for too small canals.2.There was no significant difference between the Electronic measuring length and the Actual length (P＞0.05).3.In locating the major foramen,the ROOT ZX apex locator was 75.65%,95.34%and 100%accurate to within±0.5mm,±1.0mm,and±1.5mm respectively.In locating the minor foramen,the ROOT ZX apex locator was 77.71%,98.09%and 99.36%accurate to within±0.5mm,±1.0mm and±1.5mm respectively.4.Five-way ANOVA showed that among these factors, including vital/necrotic pulp,single-rooted/multi-rooted,small/large K-file and dry/wet canal,only measurements of the vital pulp provided greater accuracy compared with the necrotic ones(F=5.037,P=0.025＜0.05)in locating both the major and minor foramen,but the difference(0.08mm)were not clinically significant,other factors had no significant influence(P＞0.05)on the measurement error with all the interactions between these factors being insignificant(P＞0.05).Conclusion The result of this study indicates that the ROOT ZX apex locator has high accuracy in clinical practice.The accuracy of ROOT ZX apex locator in locating both the major foramen and the minor foramen is not adversely affected by the four factors,including vital/necrotic pulp, single-rooted/multi- rooted,small/large K-file and dry/wet canal.更多还原