旋转镍钛器械与手用不锈钢器械去除根充物的效果评价

目的对比再治疗旋转镍钛器械与手用不锈钢器械去除根充物的效果。方法 54颗上切牙根管充填后分为三组(n=18),用不同方法去除根充物:A组:手用不锈钢锉+氯仿组;B组:ProTaper再治疗旋转镍钛组,不使用氯仿;C组:ProTaper+氯仿组。评价操作时间、氯仿用量及根充物残留。结果 B、C组操作时间短于A组(P<0.05),使用氯仿对总操作时间无影响(P>0.05),C组氯仿用量明显少于A组(P<0.01)。三组根充物总残留量无差异(P>0.05)。结论使用旋转镍钛器械去除根充物,可减少氯仿用量,缩短操作时间。     

Efficacy of ProTaper universal retreatment files in removing filling materials during root canal retreatment

The aim of this study was to evaluate the efficacy of the ProTaper Universal System rotary retreatment system and of Profile 0.06 and hand instruments (K-file) in the removal of root filling materials. Forty-two extracted single-rooted anterior teeth were selected. The root canals were enlarged with nickel-titanium (NiTi) rotary files, filled with gutta-percha and sealer, and randomly divided into 3 experimental groups. The filling materials were removed with solvent in conjunction with one of the following devices and techniques: the ProTaper Universal System for retreatment, ProFile 0.06, and hand instruments (K-file). The roots were longitudinally sectioned, and the image of the root surface was photographed. The images were captured in JPEG format; the areas of the remaining filling materials and the time required for removing the gutta-percha and sealer were calculated by using the nonparametric one-way Kruskal-Wallis test and Tukey-Kramer tests, respectively. The group that showed better results for removing filling materials was the ProTaper Universal System for retreatment files, whereas the group of ProFile rotary instruments yielded better root canal cleanliness than the hand instruments, even though there was no statistically significant difference. The ProTaper Universal System for retreatment and ProFile rotary instruments worked significantly faster than the K-file. The ProTaper Universal System for retreatment files left cleaner root canal walls than the K-file hand instruments and the ProFile Rotary instruments, although none of the devices used guaranteed complete removal of the filling materials. The rotary NiTi system proved to be faster than hand instruments in removing root filling materials.     

Three-dimensional evaluation of effectiveness of hand and rotary instrumentation for retreatment of canals filled with different materials

The aim of this study was to measure the remaining filling volume of different obturation materials from root-filled extracted teeth by using 2 removal techniques. Eighty single-rooted teeth were collected and decoronated, and the root canal was prepared by using the ProTaper nickel-titanium rotary files. The teeth were randomly allocated into 4 groups, and each group was obturated by using a different material. Group 1 was filled with gutta-percha and TubliSeal sealer, group 2 was filled with EndoRez points and EndoRez sealer, group 3 was filled with RealSeal points and RealSeal sealer, and Group 4 was filled with a gutta-percha point and GuttaFlow sealer. Teeth were scanned with a micro-computed tomography scan, and then root fillings were removed by using ProTaper retreatment files or hand K-files. Teeth were scanned again, and volume measurements were carried out with micro-computed tomography software. Statistical analysis showed significant differences between the 2 removal techniques for gutta-percha and for both techniques between gutta-percha and the other groups. The present study showed that all tested filling materials were not completely removed during retreatment by using hand or rotary files. Gutta-percha was more efficiently removed by using hand K-files.     

The efficacy of two rotary NiTi instruments and H-files to remove gutta-percha from root canals

Objective: The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment. Study design: Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05). Results: All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05). Conclusions: Under the experimental conditions, the remaining filling material after retreatment was similar for each group. Key words:Gutta-percha removal, K3®, NiTi, R-Endo®.     

Hero Shaper镍钛机用器械去除根管旧充填物能力的体外研究

目的　研究Hero Shaper 镍钛机用根管预备器械去除根管旧充填物的能力。方法　选取临床拔除的48 个单根管前牙, 随机分为2组, 用改良式逐步后退法进行根管预备, 牙胶尖与碧兰糊剂侧方加压充填根管。放置30 d后用不同的方法去除根管旧充填物:A组为H型锉+氯仿组;B组为Hero Shaper+氯仿组;记录操作时间。将牙根纵劈,立体显微镜下观察根管冠1/3 ,中1/3 ,根1/3的残留物情况。结果　在根管的3部分,2种方法清理后的残留物量均无统计学差异(P>0.05)。B组操作时间明显少于A组,具有统计学差异(P<0 .01)。结论　根管再治疗中,使用Hero Shaper镍钛机用根管预备器械可以减少操作时间,获得和H锉相似的清理效果。     

3种器械去除根管内牙胶充填物的效果评价

目的：比较H型锉和两种再治疗镍钛旋转器械去除根充物的效果。方法：45颗离体单根管下颌前磨牙,使用ProTaper镍钛器械根管预备,热牙胶垂直加压根管充填。标本随机分为3组（n=15）用不同方法去除根充物。A组H型锉、B组ProTaper Universal和C组Hero Shaper,分别记录再治疗所用时间。将标本沿牙体长轴纵劈,用立体显微镜观察根管壁残留的牙胶,t检验和单因素的方差分析one way ANOVA进行统计学分析。结果：B组根管内残留充填物的量较其他两组更少（P〈0.05）;B、C两组操作时间明显短于A组（P〈0.05）,而B、C两组间,C组用时较少,但没有显著性差异。结论：根管再治疗中,所有器械均会残留根充物,ProTaper Universal镍钛再治疗器械可以有效去除单根管下颌前磨牙根管内充填物。     

Gutta-percha retreatment: effectiveness of nickel-titanium rotary instruments versus stainless steel hand files

This study compared the cleanliness of the root canal walls after retreatment using nickel titanium (NiTi) rotary and stainless steel (SS) files. Also compared were time of retreatment and canal deviation. Forty extracted canines were step-back prepared and obturated with gutta-percha and sealer. Retreatment was performed either by using chloroform and SS hand files or chloroform and NiTi rotary files. Time for retreatment was recorded. Radiographs of the root canal system before and after retreatment were made. Teeth were split longitudinally, photographed, and projected onto a screen. The amount of gutta-percha/sealer remaining on the canal walls was then traced and measured. The amount remaining was analyzed and compared statistically between NiTi and SS groups by t test. Results showed that the mean percentage of wall coverage by remaining obturating material in the SS group was 13.6% and was 15.2% for the NiTi group. There was no statistically significant difference (p = 0.361). No severe canal deviation occurred with either retreatment method. Mean retreatment time for the SS group was 6.3 min and 7.9 min for the NiTi group; the difference was statistically significant (t test p < 0.001). In conclusion, NiTi rotary and SS hand were similar in material remaining after retreatment, but SS hand was a bit faster.     

Desocclusol和氯仿辅助去除根充材料的体外研究

目的 研究Desocclusol和氯仿辅助去除根充材料的能力,为临床根管再治疗寻找新型的根充物辅助溶剂提供依据.方法 选择因正畸需要拔除的离体上颌双根双根管第一前磨牙40颗,经开髓、根管预备后随机分为4组,每组10颗牙,20个根管.A组:普通根充糊剂和牙胶尖根充后用Desocclusol和K锉去除根充物.B组:普通根充糊剂和牙胶尖根充后用氯仿和K锉去除根充物.C组:碧兰CORTISOMOL永久性根充糊剂和牙胶尖根充后用Desocclusol和K锉去除根充物.D组:碧兰CORTISOMOL永久性根充糊剂和牙胶尖根充后用氯仿和K锉去除根充物.分别记录各组成功去除根充物的根管数、操作时间、失败情况及原因.各组之间操作时间的比较采用t检验.结果 4组成功去除根充物的根管数分别为18、19、20、18个.操作时间比较,A组与B组差异无统计学意义(P＞0.5),A组与C组差异无统计学意义(P＞0.5),C组少于D组(P＜0.01),B组少于D组(P＜0.01).结论 Desocclusol是有效的根充物的辅助溶剂.     

The effect of root canal preparation on microleakage within endodontically treated teeth: an in vitro study

AIM: The purpose of this study was to evaluate the effects of smear layer and canal instrumentation on leakage in root-filled teeth. METHODOLOGY: Six groups (n = 12) of freshly extracted human canines and premolars with closed apices and single roots were used. Groups A, B, C, and D were instrumented with engine-driven rotary nickel-titanium MCXIM files and Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3.0 mL of 17.0% REDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% NaOCl, then obturated with AH-26 sealer and either the lateral condensation (Groups C-E) or thermomechanical compaction technique (Groups A and B). Copper wire was placed coronally in contact with the gutta-percha in each tooth and, after immersion in 0.9% NaCl solution, a 10 volt dc voltage was connected between each tooth and a stainless steel electrode. The current flow in the circuit was observed for 45 days. One way ANOVA and Duncan's Multiple Range Test were used to compare Groups A-F at time intervals of 10, 20, 30 and 45 days and identify statistically significant differences. RESULTS: Significantly less microleakage occurred when the smear layer was removed and when the canals were obturated with thermoplasticized gutta-percha. Canals instrumented with engine-driven NiTi files exhibited less leakage than hand-instrumented canals irrespective of obturation method. CONCLUSIONS: Smear layer removal is beneficial to root canal sealing. Obturation with thermoplasticized gutta-percha provides a superior seal whilst canal instrumentation with engine-driven NiTi files reduces the extent of microleakage in root canals.     

Efficacy of two rotary NiTi instruments in the removal of Gutta-Percha during root canal retreatment

The aim of this study was to evaluate the efficacy of ProTaper and K3 in the removal of gutta-percha during root canal retreatment in comparison with hand Hedstrom files. Time of gutta-percha removal and amount of apically extruded debris were also evaluated. Sixty extracted single-rooted anterior teeth and premolars were instrumented and obturated with laterally condensed gutta-percha technique. The teeth were cleared and randomly divided into three groups of 20 teeth each. The roots were split longitudinally, digital images were created using a scanner, and the areas of remaining filling material were traced using Ulead Photoimpact7 then calculated using SigmaScan software. The results indicated that the two rotary nickel-titanium instruments left significantly less remaining filling material than hand instruments (p < 0.001). The ProTaper and K3 required significantly less time for filling material removal than hand instruments (p < 0.001). There was no statistically significant difference among the three techniques regarding the amount of apically extruded debris (p = 0.159). In conclusion, ProTaper and K3 were found to be effective and faster in removing gutta-percha.     

FlexMaster镍钛机用器械根管再治疗清理效果的体外研究

目的研究FlexMaster镍钛机用器械根管再治疗清理的效果。方法选取临床拔除的40颗单根管前牙,用改良式逐步后退法进行根管预备,牙胶尖与碧兰糊剂侧方加压充填根管。放置30d后随机分为两组,A组用H型锉去除根管内旧充填物,B组用FlexMaster镍钛机用器械去除充填物。分别记录操作时间。然后,将牙根纵劈,立体显微镜下观察根管冠1/3、根中1/3和根尖1/3段的残留物情况。结果在根管冠1/3处两种方法的根管清理效果无统计学差异（P〉0.05）。在根管的中段和根尖段,B组的残留物量较A组少,两组间存在显著性差异（P〈0.05）。B组操作时间明显少于A组,两组间也有显著性差异（P〈0.01）。结论与手用H型锉相比,FlexMaster镍钛机用根管预备器械去除根管旧充填物效果更好,且操作时间显著减少。     

Comparison between gutta-percha and resilon removal using two different techniques in endodontic retreatment

This study compared the remaining filling material and working time when removing gutta-percha/AH 26 and Resilon/Epiphany from root filled extracted teeth. The root fillings were removed using chloroform and two different rotary systems (K3 and Liberator files). The amount of residual filling material on the canal walls was imaged and measured using image analyzer software. The group filled with Resilon/Epiphany and retreated with K3 files demonstrated the least residual filling material on the walls (p < 0.05). There was no statistically significant difference between the gutta-percha/AH26 and Resilon/Epiphany groups when the Liberator files were used (p > 0.05). In the groups filled with Resilon/Epiphany, the filling was removed faster than groups filled with gutta-percha/AH 26 (p < 0.05). K3 rotary system was faster than Liberator to remove both gutta-percha and Resilon (p < 0.05). Resilon/Epiphany was effectively removed with K3 or Liberator rotary files.     

2种镍钛器械对根管充填物清除效率比较

目的:比较Mtwo R再治疗锉、Reciproc锉与手动器械在根管再治疗过程中对根管内充填物的清除效率.方法:取45颗离体下前牙,清理根管后,预备至40#.牙胶尖和AH Plus糊剂以冷侧压法充填根管.随机分为3组,分别用手用器械、Mtwo R和Reciproc去除根管内充填材料,收集推出根尖孔的碎屑,称重,记录所用时间.样本沿长轴颊舌向劈开,显微镜下进行观察、评分.采用SPSS 13.0软件包对数据进行统计学分析.结果:3种方法碎屑推出量和管壁清洁度无显著差异(P＞0.05),Mtwo R组和Reciproc组用时更少(P＜0.05).结论:镍钛器械并不能完全清除根管充填物,但可以提高效率.     

Efficacy of five rotary systems versus manual instrumentation during endodontic retreatment

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.     

In Vitro Evaluation of the Effectiveness of ProTaper Universal Rotary Retreatment System for Gutta-Percha Removal with or without a Solvent

IntroductionEffective removal of gutta-percha in endodontic retreatment is a significant factor to ensure a favorable outcome from failed procedures. The purpose of this study was to evaluate the efficacy of a nickel-titanium rotary instrument system with or without a solvent versus stainless steel hand files for gutta-percha removal.MethodsForty extracted human maxillary anterior teeth were prepared and filled. They were divided into 4 groups: Gates-Glidden and K-files, Gates-Glidden and K-files with chloroform, ProTaper Universal rotary retreatment system, and ProTaper Universal rotary retreatment system with chloroform. The operating time was recorded. The teeth were longitudinally sectioned and photographed. The images were analyzed and the filling remnants were quantified by using the IMAGE TOOL software.ResultsWith Kruskall-Wallis test, statistical analysis showed that there was no significant difference between the techniques in regard to the amount of the endodontic filling remnants (P < .05); however, the ProTaper Universal rotary retreatment system was faster than the hand files (P < .05).ConclusionsAll of the techniques proved helpful for the removal of endodontic filling material, and they were similar in material remaining after retreatment, but the ProTaper Universal rotary retreatment system without chloroform was faster.     

Evaluation of Root Canal Obturation: A Three-dimensional In Vitro Study

The aim of the study was to measure percentage of volume of voids and gaps in root canals obturated with different obturation materials by using micro–computed tomography (micro-CT). Forty-eight single-rooted teeth were collected and decoronated, and root canals were prepared by using rotary files. The roots were randomly allocated into 4 groups, and each group was obturated by using cold lateral compaction with a different material (gutta-percha and TubliSeal sealer, EndoRez points and EndoRez sealer, RealSeal points and RealSeal sealer, and a gutta-percha point and GuttaFlow sealer). Roots were scanned with micro-CT, and volume measurements for voids and gaps in the obturated roots were carried out by using specialized CT software. Percentage of gaps and voids was calculated. Statistical analysis showed that gutta-percha exhibited an overall significantly lower percentage (1.02%) of voids and gaps. The present study showed that none of the root canal filled teeth were gap-free. Roots filled with gutta-percha showed less voids and gaps than roots filled with the remaining filling materials.     

Influence of gutta-percha points on the filling of simulated lateral canals

The aim of this study was to investigate, in vitro, the percentage of filling of simulated lateral canals in teeth obturated with TP medium and standardized gutta-percha points. Twenty human mandibular canines were prepared with LA Axxess (SybronEndo) and K3 Endo rotary system (SybronEndo) up to a #50 file, according to the Free Tip Preparation Technique. During instrumentation, the root canals were alternately irrigated with 1% sodium hypochlorite and 17% EDTA. Six artificial lateral canals were prepared at the apical third of each tooth. Then, the teeth were assigned to two groups (n=10): Group 1 - filled with TP medium master gutta-percha points (Dentsply, Mailleffer); Group 2 - filled with standardized master gutta-percha points (Dentsply, Mailleffer). Root canal filling was complemented with AH Plus sealer (Dentsply, Mailleffer) and accessory gutta-percha points (Dentsply, Mailleffer), according to the classic technique. The teeth were radiographed and the images obtained were digitized. Linear measurements of the percentage of filling of the artificial lateral canals in each group were accomplished on the Image Tool 2.02 software. Statistical analysis of the data using Mann-Whitney U non-parametric test evidenced significant difference (p<0.01) between the experimental groups. The group obturated with TP medium points yielded higher percentage of filling of the lateral canals. It may be concluded that the use of master gutta-percha points with larger taper resulted in better filling of the simulated lateral canals, as compared to the use of standardized master gutta-percha points.     

Effectiveness of different techniques for removing gutta-percha during retreatment

AIM: To evaluate the effectiveness of various techniques for removing filling material from root canals in vitro. METHODOLOGY: Eighty extracted mandibular premolar teeth were selected for the study. The teeth were root filled using thermomechanical compaction of gutta-percha. After 8 months, the filling material was removed and canals were reinstrumented using the following techniques: group I - hand instrumentation with K-type files (SybronEndo, Orange, CA, USA); group II - K3 Endo System (SybronEndo); group III - M4 system (SybronEndo) with K-type files (SybronEndo); and group IV - Endo-gripper system (Moyco Union Broach, York, PA, USA) with K-type files (SybronEndo). The amount of filling debris remaining on root canal walls was assessed radiographically; the images were digitized and analysed using AutoCAD 2000 software. Total canal area, area of the cervical, middle and apical thirds, and area of remaining filling material were outlined by one operator. The ratios between these areas were calculated as percentages of remaining debris. Thereafter, data were analysed by means of one-way anova and the post-hoc Duncan test to identify differences between the four techniques. RESULTS: Multiple comparisons of the percentages of remaining filling material in the entire canal did not reveal any significant differences between the methods of removal. However, when each third was analysed separately, significant differences for remaining debris were present between groups. The apical third had the most remaining material, whilst the cervical and middle thirds were significantly cleaner (P = 0.002). Comparison of the techniques revealed that teeth instrumented with K3 rotary instruments had a lower ratio of remaining filling material in the apical third (P = 0.012). CONCLUSION: In the apical third, K3 rotary instruments were more efficient in removing gutta-percha filling material than the other techniques, which were equally effective for the other thirds.     

Effectiveness of ProFile .04 taper rotary instruments in endodontic retreatment

This study investigated the retreatment effectiveness of .04 Taper nickel-titanium rotary ProFiles. Thirty extracted single-rooted anterior teeth were instrumented and obturated with gutta-percha/Roth's Sealer using lateral condensation. They were distributed into three groups of 10 each. Retreatment for group A was done using Profile alone, group B using Profile and chloroform, and group C using hand files with chloroform. The teeth were then split longitudinally into halves. The remaining gutta-percha/sealer on the root canal wall in the cervical, middle, apical thirds, and the whole canals were visually scored with the aid of light microscopes. The results showed that the mean scores in groups A and B were generally lower (better) than group C. Mean scores of the apical thirds tended to be higher (worse) than the middle and the cervical thirds, except in group A. ProFile with or without chloroform seemed to be a viable alternative retreatment method.     

Endodontic retreatment: ultrasonics and chloroform as the final step in reinstrumentation

Forty extracted teeth were instrumented using a step-back flare technique and obturated with gutta-percha and either AH26 or Roth's 801 sealer. After 3 months the canals were retreated by removing gutta-percha and sealer with hot instruments followed by chloroform and files. As a final step, the teeth were instrumented using ultrasonics with either chloroform or with NaOCl. Most teeth were well cleaned. No significant differences were found between sealer groups or between the two irrigants as to the ability to remove gutta-percha/sealer.