2种根尖定位仪诊断牙根纵裂的临床研究

目的研究RootZX和ProPex根尖定位仪用于诊断牙根纵裂的可靠性与准确性。方法分别用RootZX和ProPex根尖定位仪测量临床上疑为牙根纵裂患牙的根管工作长度,按照测量长度插入诊断丝,拍摄X线片。正常根管中诊断丝止于距根尖孔0．5～1．0mm范围内,诊断丝终止位置距根尖孔长度为牙根长度1／3及以上者初步诊断为牙根纵裂。拔除患牙后测量根管实际长度与纵裂根管长度,与电测长度进行比较。结果临床疑似牙根纵裂患牙48颗,经根尖定位仪联合X线检查初步诊断牙根纵裂48颗,拔牙后确诊牙根纵裂42颗,确诊率为87．5％。42颗牙根纵裂患牙中,RootZX电测长度平均值为（8．78±0．87）mm;ProPex电测平均值为（8．73±0．85）mm;根管实际长度平均值为（19．26±0．82）mm;纵裂根管长度平均值为（8．61±0．78）mm。RootZX和ProPex2种根尖定位仪的电测长度皆小于根管实际长度（P〈0．001）;RootZX电测值、ProPex电测值、纵裂根管长度之间差异无统计学意义（F=1．342,P〉0．05）。结论根尖定位仪有助于牙根纵裂的临床诊断。     

根尖定位仪定位根管纵折的体外研究

目的：研究两种不同多频根尖定位仪定位根管纵折的能力及相关影响因素。方法：在釉牙骨质界处截除43颗单根管下颌前磨牙牙冠。在牙根冠方制备水平参考平面,牙根的近中或远中面打磨出平行于牙根长轴的水平面。随机用3种不同规格的金刚砂片在水平面上沿根管长轴制备一条联通根管的水平槽。根尖定位仪PROPEXⅡ与JustyⅡ在固定测量装置上分别定位水平槽上端顶点并计算测量锉尖与顶点的距离（DEUL）。在显微镜下测量水平槽的大小以及上下顶点距离根尖和冠方参考平面的距离。结果采用Mann-Whitney U检验和相关分析。结果：PROPEXⅡ和JustyⅡ测量DEUL值间无显著性差异,平均值分别为0.904mm和0.711mm,分别定位60.46%（n=26）和65.21%（n=28）测量锉尖距离槽上顶点冠方1.0mm范围内。两种根尖定位仪测量值与水平槽的面积和宽度显著性相关（P〈0.05）。结论：在本研究条件下,两种多频型根尖定位仪不能精确定位不完全纵折,但可以为临床上牙根不完全纵折早期诊断提供参考。根尖定位仪测量值变化与纵折大小相关,与其位置无关。     

ProPex 根尖定位仪准确性的临床研究

目的研究ProPex根尖定位仪在临床测量根管工作长度的准确性。方法选择60颗患牙98个根管,先以ProPex根尖定位仪确定根管工作长度,再插入初尖锉至根尖定位仪确定工作长度,拍摄X线片测量、计算根管工作长度,将测得数据进行配对t检验。结果 ProPex根尖定位仪测量结果为(18.5±2.1)mm,插针X线法测量结果为(18.4±2.0)mm,两者差异无统计学意义(t=-1.845,P=0.068)。结论 ProPex根尖定位仪与插针X线法的测量结果无明显差异,是一种较为可靠的确定根管工作长度的方法。     

根尖定位仪测量根尖破坏牙根管长度的准确性研究

目的 比较Root ZX,Propex,Justy Ⅱ和 Raypex5 4种根尖定位仪测量根尖受破坏牙齿工作长度的准确性.方法 将53颗离体牙沿釉牙骨质界截冠、去髓,根管预备到25#,使用Root ZX(A组),Propex(B组),Justy Ⅱ(C组)和 Raypex5(D组) 4种根尖定位仪分别测量每个根管的工作长度;再使用超声倒预备工作尖将以上各牙沿根尖孔破坏根尖狭窄部,再次用4种根尖定位仪测量工作长度.结果 所得数据与解剖镜下测量的实际数据进行比较,根尖完整时A、B、C、D4组数据在-0.5～0.5 mm误差范围内的百分数分别为86.3%、88.8%、85.0%、88.8%.根尖破坏时A、B、C、D4组数据在-0.5～0.5 mm误差范围内的百分数分别为16.7%、20.5%、10.3%、48.7%,在-1～1 mm误差范围内的百分数分别为74.4%、52.6%、57.7%、91.0%.结论 4种根尖定位仪对于根尖破坏的牙齿测量准确性比根尖完整的牙齿要低,相比之下Raypex5的准确性比较高.     

3种根尖定位仪在口腔急诊应用的临床评价

目的评估口腔急诊需要进行根管治疗的各型急性牙髓炎、急性根尖周炎及牙外伤露髓的患牙,应用3种根尖定位仪测量根管工作长度的准确性。方法对口腔急诊就诊的需要进行根管治疗的284名患者,共317颗患牙随机分为3组,分别采用JustyII、Raypex5和PropexⅡ根尖定位仪进行根管工作长度测量,根据测量值进行根管预备和根管充填,并通过根充后x线根尖片的恰填率进行对比,评价3种根尖定位仪的准确性。结果口腔急诊条件下,3种根尖定位仪准确性有所不同,前牙和前磨牙测量结果3种都较理想;磨牙测量时Raypex5和PropexⅡ更为准确（P〈0．01）。各种急性牙髓炎和急性根尖周炎的比较中,PropexII测量的准确性（分别为94．87％和90．91％）均高于另2种根尖定位仪,受口腔急症患牙干扰因素影响最小。结论PropexⅡ根尖定位仪准确性高,稳定性好,较JustyⅡ和Raypex5更适合在口腔急诊条件下应用。     

ProPex根尖定位仪在C形根管系统准确性的研究

目的 对ProPex根尖定位仪测量C形根管工作长度的准确性进行评价。方法 对24颗即将拔除的、术前X线片显示牙根部呈锥形或方形融合、开髓后证实为C型根管的下颌第二磨牙局麻下开髓、拔髓、冲洗,用ProPex根尖定位仪测量78个根管的工作长度(WL);完整拔除牙齿后测量根管的实际长度(AL),比较WL与AL的长度差异。结果 以距根尖孔以内0.5mm为误差标准,ProPex根尖定位仪准确率为85.90%;以距根尖孔以内1.0mm为标准,准确率为91.03%;以距根尖孔以内1.5mm为标准,准确率为94.87%。结论 Propex根尖定位仪在C形根管工作长度确定方面的准确性较高,具有简便、快速、准确、安全、避免多次X线照射等优点,能大大缩短临床椅旁时间,提高根管治疗的效率。     

三种根管长度测量仪测定根尖吸收牙齿工作长度准确性的比较研究

目的　比较三种不同根管长度测量仪测定根尖区吸收牙齿工作长度结果的准确性。方法　将 6 0颗离体前牙平均分成三组 ,用 70 0 # 裂钻深入根尖孔钻入 3mm ,破坏根尖狭窄处。将三组牙齿分别放置于测量槽中 ,使用RootZX、Neosonic和JustyⅡ测量其工作长度。结果　所得出的数据与肉眼下准确测量所得出的数据比较 ,A组在± 0 .5mm 6 5 .0 %、± 1mm 85 .0 %、± 1.5mm 10 0 .0 %。B组在± 0 .5mm 6 0 .0 %、± 1mm 85 .0 %、± 1.5mm10 0 .0 %。C组在± 0 .5mm 75 .0 %、± 1mm 90 .0 %、± 1.5mm 10 0 .0 %。结论　三种测量仪测量值具有准确性 ,A组、B组和C组无明显差异     

不同根管环境对Root ZX和ProPex准确性的影响研究

目的评价不同根管环境时,Root ZX和ProPex2种根管长度测量仪的测量准确性。方法选取新鲜拔除的30颗下颌单根管前磨牙,测量根管实际长度（L）后,在4种测量环境（3%H2O2溶液、0.9%NaCl溶液、2.5%NaClO溶液、根管干燥状态）下,用根管长度测量仪Root ZX和ProPex测量根管长度,得到工作长度L（R使用Root ZX测量值）和L（P使用ProPex测量值）,再将上述样本沿牙根纵轴方向,用金刚砂车针磨出剖面,测量根尖剖面最狭窄点至解剖根尖孔的距离（D）,计算L与D的差值得到根管实际工作长度。结果使用不同冲洗液（3%H2O2溶液、0.9%NaCl溶液、2.5%NaClO溶液）冲洗根管及根管干燥状态时,Root ZX和ProPex测定的工作长度与根管实际工作长度的差异无统计学意义（P〉0.05） 相同根管环境时,Root ZX和ProPex测量偏差有统计学意义（P〈0.05）,但在±0.5mm范围内,Root ZX和ProPex的测量准确率的差异无统计学意义（P〉0.05）。结论Root ZX和ProPex测量准确性不受根管环境影响,与根管干燥和湿润无关,且两者的测量准确性无明显差异。     

根尖狭窄破坏对Propex Ⅱ电子根尖定位仪准确性的影响

目的:研究在根尖狭窄破坏的情况下,PropexⅡ测量准确性与根尖孔大小的相关性.方法:磨除40颗单直根管离体牙根尖l mm,采用2％液态琼脂凝胶注入卡斯特罗模型,使用PropexⅡ电子根尖定位仪进行根管长度测量,记录测量值(LP),计算实际测量的根管工作长度(L)与电测法测量的根管工作长度(LP)的差值(△L).显微镜下拍摄根尖孔图像,利用Photoshop CS 6.0软件测量根尖孔面积(S).采用SPSS 22.0软件包对测量结果进行直线相关回归分析.结果:以±0.5 mm作为△L的允许范围,△L均为正值.在根尖狭窄破坏的情况下,PropexⅡ的测量准确率为52.5％.R值为0.903,S与△L呈线性相关.建立的线性回归方程为:S=0.04+0.11×△L.结论:在根尖狭窄破坏的情况下,电子根尖定位仪准确性下降;根尖孔面积越大,准确性越差.     

根尖定位仪测量准确率的实验研究

目的:研究在根尖孔直径为0.2 mm,单一电介质条件下根尖定位仪(EAL)测量准确率.方法:采用琼脂凝胶和30颗单根管离体牙构建根尖定位仪体外评价模型,使用两种EAL在同一种电介质中对30个离体牙进行根管长度测量,记录测量值在真实值±0.5 mm范围内频数分布.采用Fisher检验进行统计学分析.结果:两种EAL测量值在距离真实值±0.5 mm范围内均为28个(93.3%),超出真实值 0.5 mm范围均为2个(6.7%).两组间无统计学差异(P＞0.05).结论:在本实验条件中,两种根尖定位仪均能准确测量根管长度.     

Distance from file tip to the major apical foramen in relation to the numeric meter reading on the display of three different electronic apex locators

Aim  To establish and compare the relationship between the distance from the file tip to the apical foramen and the numeric meter reading on the display of three different electronic apex locators (EALs).
Methodology  A total of 12 extracted intact, straight, single-rooted human teeth with complete roots were used. The actual root canal length (AL) was determined after access preparation. For the electronic measurements with each EAL, silicon stops were fixed with auto-polymerizing resin to size 15 K-files at AL and 0.5, 1, 2, 3, 4 mm short of AL. The data was analysed by two-way anova and Tukey's honestly significant difference (HSD) test for multiple comparisons amongst EALs. Additionally, one-way anova and Tukey's HSD test were carried out for multiple comparisons amongst the measurements of each EAL.
Results  There was a statistically significant difference amongst all EALs in indicating the position of file tips in relation to the major foramen ( P  < 0.05). The correlation between the meter reading and the position of the file tip from the apical foramen was statistically significant in the three EALs. There were significant differences amongst the measurements at distances from 0 to 2 mm in Justy III. In Dentaport, significant differences were found from 0 to 1 mm. However, the E-Magic Finder showed significant differences from 0 to 0.5 mm.
Conclusions  Justy III was more capable of displaying the intracanal position of the file tip from the major foramen in mm whilst advancing through the root canal during electronic measurements than the Dentaport and E-Magic Finder Deluxe.     

Influence of instrument size on the accuracy of different apex locators: an in vitro study

The aim of this in vitro investigation was to determine the accuracy of 4 different electronic apex locators (EALs) with 3 different instrument sizes. For this study 146 roots were embedded in an agar solution. Electronic measurements were made to the physiologic foramen (apical constriction) with the Elements Apex Locator, Justy II, Raypex 5, and ProPex II and K-type files sizes 08, 10, and 15. Statistical significances were calculated with the sign test (P < .001). Exact measurements to the physiologic foramen were made with the Elements Apex Locator, 36.99%, 39.04%, and 44.93%; Justy II, 38.62%, 32.41%, and 43.41%; Raypex 5, 42.76%, 39.31%, and 39.06%; and ProPex II, 38.62%, 43.45%, and 40.63% of the time with instrument sizes 08, 10, and 15, respectively. No significant differences were found between the actual working length and EALs/instrument size. A nonsignificant higher number of unstable measurements were observed in all EALs with instrument size 15.     

Ex vivo comparison of two electronic apex locators with different scales and frequencies

AIM: To compare ex vivo the accuracy of two impedance quotient apex locators with different scales and frequencies of the measuring circuit. METHODOLOGY: In each root of 193 extracted human teeth, electronic working length determination (ELD) was carried out with a newly constructed measuring unit. In all cases, ELD was performed using the apex locators Justy II (Hager & Werken, Duisburg, Germany) and Raypex (VDW, Munich, Germany) on the scale points (sp) 0/0.5/1 of each device. A Miller Needle reaching working length was fixed with composite. The corresponding sp and the differences to the other sp were recorded. After histological preparation of the apical region, the teeth were examined under a light microscope. The distances of the Miller Needle tips to the target intervals 'minor foramen-major foramen' and 'apical canal constriction' (apical constriction) were determined for each sp for both devices. The data were statistically analysed by a chi-square test. RESULTS: Precise determination of the target interval 'minor foramen-major foramen' was successful with Raypex 4 in 94.8% (sp 1), 90.7% (sp 0.5) and 72.5% (sp 0) of cases and with Justy II in 59.6% (sp 1), 92.2% (sp 0.5) and 68% (sp 0) of cases. No measurement carried out by Raypex 4 and by Justy II on sp 1 was beyond the major apical foramen. However, on sp 0.5, there were eight measurements for Raypex 4 and four measurements for Justy II beyond the major apical foramen. Overinstrumentation was also recorded for sp 0 in 49 specimens (Raypex 4) and 59 specimens (JustyII). The major apical constriction was met exactly by Raypex 4 in 50.7% (sp 1), 14% (sp 0.5) and 5.2% (sp 0) of cases and by Justy II in 32.1% (sp 1), 23.8% (sp 0.5) and 4.1% (sp 0) of cases. The differences between the determination made with the sp suggested by the manufacturers for Raypex 4 (sp 1) and Justy II (sp 0.5) were not significant (P > 0.05) for the target interval 'minor foramen-major foramen' and significant (P 相似文献   

In vitro evaluation of the ability of three apex locators to determine the working length during retreatment

The purpose of this in vitro study was to evaluate the accuracy of three apex locators in determining the working length during the retreatment process. Twenty extracted single-rooted human teeth with mature apices were used in this study. The root canal length of each tooth was measured placing a #15 file until the tip was visible at the apical foramen. The direct visual measurement was reduced by 0.5 mm and recorded. The root canals were instrumented and filled to the direct visual measurement using lateral compaction technique. After 7 days the teeth were retreated using three apex locators: ProPex, NovApex, and Root ZX, for determining the retreatment working length. Afterward, comparison between the visual working length and the retreatment working length were made. ProPex, NovApex, and Root ZX were accurate within 0.5 mm 80, 85, and 95% of the time, and within 1 mm 95, 95, and 100%, respectively. No significant differences were detected between the three apex locators (p > 0.05).     

The accuracy of electronic working length determination

AIM: To determine in vivo the accuracy of two impedance quotient apex locators under clinical conditions. METHODOLOGY: Electronic working length determination was carried out before extraction in 79 human teeth with 93 root canals. In 51 root canals, the determination was performed using the apex locator Justy II(R) (Hager & Werken, Duisburg, Germany); in 42 canals, the apex locator Endy 5000(R) (Loser, Leverkusen, Germany) was used. A root canal instrument was fixed at working length with composite material prior to extraction followed by the exposure of a radiograph. After histological preparation of the apical region, the teeth were examined under a light microscope. The distance of the file tips to the target intervals 'minor foramen - major foramen' and 'apical canal constriction' was determined. These values were compared with the calculated working lengths, determined by radiographic assessment. The data were statistically analysed by a paired t-test. RESULTS: For both apex locators and both target intervals, no significant differences between the electronic and radiographical assessments were recorded. The probability of determining the area between minor and major foramen was 82.4% for Justy II and 81% for Endy 5000. However, accurate determination of the apical constriction was only successful in 51% (Justy II) and 64.3% (Endy 5000) of canals. Variation of the inaccurate measurements was higher for Endy 5000 than for Justy II. CONCLUSIONS: Under clinical conditions, it is possible to determine the region between the minor and major apical foramen with electronic length measuring devices (ELD). However, use of these devices does not result in precise determination of the apical constriction.     

Ex vivo accuracy of three electronic apex locators using different apical file sizes

This study evaluated the accuracy of three electronic apex locators (Root ZX, Novapex, and Justy II) in root canal length determinations using different apical file sizes, considering the apical constriction (AC) and the major foramen (MF) as anatomic references. The diameter of the apical foramina of 40 single-rooted teeth was determined by direct visual measurement and the master apical file was established. Electronic measurements were then performed using 3 instruments: the selected master apical file (adjusted file), one size smaller (intermediate file), and two sizes smaller (misfit file). The distances from the tip of files fixed in the canals to the MF and to the AC were measured digitally. Precision at AC and at MF for the misfit, intermediate and adjusted apical files was as follows: 80%/88%/83% and 78%/83%/95% (Root ZX); 80%/85%/80% and 68%/73%/73% (Novapex); and 78%/80%/78% and 65%/78%/70% (Justy II). Considering the mean discrepancies, statistically significant differences were found only for the adjusted file at MF, with Root ZX presenting the best results at MF. The chi-square test showed significant differences between the acceptable measurements at AC and at MF for the Justy II and Novapex (± 0.5 mm) regardless of file adjustment. Under the conditions of the present study, all devices provided acceptable electronic measurements regardless of file adjustment, except for Root ZX which had its performance improved significantly when the precisely fit apical file was used. Justy II and Novapex provided electronic measurements nearest to the AC.     

Accuracy of three electronic apex locators in determining the apical foramen in multi‐rooted teeth: Randomised clinical and laboratory study

This study aimed to compare the accuracy of three electronic apex locators (EALs), Raypex 5, Apex NRG and ProPex II, in locating the apical foramen (AF) in vivo. Thirty multi‐rooted teeth were included in the study. Distances from the file tip to the radiographic apex from the buccal (R1) and mesial (R2) aspect were measured after extraction. The distance from the file tip to the AF (L) was measured microscopically. Raypex 5, Apex NRG and ProPex II were accurate to within ± 0.5 mm in 84.6%, 78.6% and 66.7% of cases, respectively. R1, R2 and L measurements between the EALs were not statistically different (P > 0.05). R1 and L correlated positively (r² = 0.817; P < 0.001). There were no significant differences in all measurements between vital and non‐vital root canals (P > 0.05). There was no statistically significant difference between the EALs. There was a positive correlation between electronic and radiographic measurements when locating the AF.     

Comparison of four electronic root canal length measurement devices

Objective: The objective of this study is to evaluate the performance of four electronic root canal length measurement devices (ERCLMDs) [Root ZX, Raypex 6, ProPex II, and VDW Gold with ERCLMD] in wet and dry root canals with different major foramen diameters, in association with three file positions within the final 1?mm of canals.

Materials and methods: Fifty roots were divided into five groups that were instrumented apically to the terminus diameter using K-files 15, 20, 30, 40, and 60. ERCLMD measurements were made when the file tip was at major foramen, 0.5?mm and 1.0?mm short of the foramen, when the apex touched to the surface of saline or was immersed 3?mm into saline, and when the canal was dry or was irrigated with saline. The differences between the electronic lengths and the actual lengths were calculated. The data were analyzed using the three-, two-, and one-way ANOVA and the LSD test (p?Results: Overall, the four ERCLMDs demonstrated 12.8% unstable and beyond the foramen measurements (11.3%). About 85% of the beyond the foramen measurements had foramen diameters 0.40 and 0.60. ERCLMD comparisons related to the file positions in the foramen diameters showed significant differences between ERCLMDs in each foramen diameter (p?Conclusions: All ERCLMDs provided highly accurate measurements within the final 1?mm of the foramen. Wet or dry canals and apex conditions did not adversely affect the accuracy of the ERCLMDs’ readings. ProPex II located the file positions in the teeth with different foramen diameters more accurately than the other ERCLMDs.