Comparison of lateral condensation and thermomechanically compacted warm alpha-phase gutta-percha with a single cone for obturating curved root canals

OBJECTIVE: To evaluate and compare the sealability and radiographic quality of root fillings in extracted teeth by using lateral condensation of gutta-percha or alpha-phase gutta-percha in conjunction with a single gutta-percha cone. STUDY DESIGN: A total of 108 single-rooted teeth were divided into 2 groups of 54 teeth based on canal shape. Canals were prepared to a minimum 0.055 taper and enlarged to a size 35 at the working distance. Irrigation was done with 17% EDTA and 2.5% sodium hypochlorite (NaOCl) to remove smear layer. One group was obturated by using cold lateral condensation of gutta-percha; the other group was obturated with thermomechanically compacted alpha-phase gutta-percha and a single cone of gutta-percha. Apical extrusion of sealer or gutta-percha was recorded. Sealability of each technique was assessed by dye penetration. The radiographic quality of obturation was also determined. RESULTS: Root canals filled with alpha-phase gutta-percha and a single cone had significantly more extrusion of sealer than canals filled by lateral condensation. Lateral condensation achieved significantly better scores for radiographic quality. There was no significant difference between the 2 filling techniques in terms of apical or coronal leakage. CONCLUSIONS: Thermomechanically condensed alpha-phase gutta-percha used in conjunction with a single gutta-percha cone had poorer radiographic quality than laterally condensed gutta-percha.     

Does cold burnishing gutta-percha create a better apical seal?

This study investigated the seal created by cold burnishing the gutta-percha exposed after apical root resection of endodontically treated teeth. Sixty single-rooted extracted human teeth with a single straight canal were divided into four experimental groups of 15 teeth each. In two of the experimental groups the canals were instrumented and obturated well with laterally condensed gutta-percha and sealer. The remaining two groups were instrumented and poorly obturated with laterally condensed gutta-percha and sealer. The apical 2 mm of all the teeth were then resected and the effect of cold burnishing the exposed gutta-percha was investigated using a linear dye penetration technique. Under the condition of this study, cold burnishing gutta-percha after apical root resection of a well-obturated root canal resulted in a poorer apical seal than if no burnishing were performed. Cold burnishing the exposed gutta-percha after apical root resection of poorly obturated root canals improved the apical seal as compared with nonburnished poorly obturated canals.     

Comparison of cold lateral condensation and a warm multiphase gutta-percha technique for obturating curved root canals

AIM: The aim of this project was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or multiphase gutta-percha obturation (Alphaseal). METHODOLOGY: A total of 108 freshly extracted human, mature single-rooted teeth were divided into two identical groups of 54 teeth on the basis of root canal shape. The canals were prepared to a minimum 0.055 taper and enlarged to size 35 at the apex. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one group were obturated using cold lateral condensation of gutta-percha and the canals of the other group were filled using a warm multiphase gutta-percha obturation technique. The extrusion of sealer and/or gutta-percha through the apex of the teeth was recorded using a simple yes/no scheme. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a four-point scale. RESULTS: Root canals filled by multiphase obturation had significantly more extrusion of sealer (P < 0.001) and gutta-percha (P < 0.001) than canals filled by lateral condensation. Canals filled by multiphase gutta-percha obturation had significantly less apical dye leakage than those obturated by lateral condensation (P < 0.05). Lateral condensation achieved significantly better scores for radiographic quality than multiphase obturation from the bucco-lingual view (P < 0.01). CONCLUSIONS: Under laboratory conditions multiphase gutta-percha had better sealability but poorer radiographic quality than lateral condensation.     

Quality of cold and warm gutta-percha fillings in oval canals in mandibular premolars

AIM: The aim of this study was to determine the quality of cold and warm gutta-percha fillings in oval canals. METHODOLOGY: Two groups of mandibular premolars with oval canals were selected after bucco-lingual and mesio-distal radiographs indicated an internal long: short diameter of > or =1.6 at a level 5 mm from the apex. After instrumentation they were obturated, respectively, by cold lateral compaction of gutta-percha cones (cold GP) and vertical compaction of warm gutta-percha (warm GP). Leakage along apical root fillings was measured using a fluid transport model. After the leakage test, horizontal sections were cut 2 and 4 mm from the apex. The area of the canal and gutta-percha in cross-sections was measured using an image analysis program. The quality of root fillings was evaluated by calculating the percentage of gutta-percha-filled canal area (PGP). RESULTS: No significant difference in leakage was found between the two groups (P = 0.570). The warm GP group produced significantly higher PGPs than the cold GP group 4 mm from the apex only (P = 0.522 at 2 mm: P = 0.000 at 4 mm). CONCLUSIONS: The percentage of gutta-percha-filled canal area using warm GP was greater than that of the cold GP in oval canals.     

A comparison of laterally condensed gutta-percha, thermoplasticized gutta-percha, and mineral trioxide aggregate as root canal filling materials

The purpose of this study was to evaluate the potential of using mineral trioxide aggregate as a root canal filling material by comparing its apical sealing ability with that of laterally condensed gutta-percha with sealer and high-temperature thermoplasticized gutta-percha with sealer in extracted bovine teeth. Sixty bovine incisors with single canals were prepared in a standard manner using LightSpeed instruments, randomly divided into three groups of 20 teeth, and obturated. The sealing ability of each technique was assessed by immersion in 1% methylene blue dye for 3 days. The teeth were cleared, and the linear extent of dye penetration was measured with a stereomicroscope. Data were analyzed by the Kruskal-Wallis one-way ANOVA followed by Dunn's test. Canals filled with laterally condensed gutta-percha or thermoplasticized gutta-percha showed significantly less apical dye penetration than canals obturated with mineral trioxide aggregate (p < 0.001). There was no significant difference in leakage between the laterally condensed group and the thermoplasticized group. The results suggest that gutta-percha obturation may provide an apical seal that is superior to MTA.     

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.     

An evaluation of .06 tapered gutta-percha cones for filling of .06 taper prepared curved root canals

AIM: To compare the area occupied by gutta-percha, sealer, or void in standardized .06 tapered prepared simulated curved canals and in mesio-buccal canals of extracted maxillary first molars filled with a single .06 gutta-percha point and sealer or lateral condensation of multiple .02 gutta-percha points and sealer. METHODOLOGY: Simulated canals in resin blocks with either a 30 degrees curve and radius of 10.5 mm (n = 20) or a 58 degrees curve and 4.7 mm radius (n = 20) and curved mesio-buccal canals of extracted maxillary first molars (n = 20) were prepared using .06 ProFiles in a variable tip crown-down sequence to an apical size 35 at 0.5 mm from the canal terminus or apical foramen. Ten 30 degrees and 58 degrees curved resin canals and 10 canals in the extracted teeth group were obturated with .02 taper gutta-percha cones and AH 26 sealer using lateral condensation. The time required to obturate was recorded. The remaining canals were obturated with a single .06 taper gutta-percha cone and AH 26 sealer. Excess gutta-percha was removed from the specimens using heat and the warm mass vertically condensed. Horizontal sections were cut at 0.5, 1.5, 2.5, 4.5, 7.5 and 11.5 mm from the canal terminus or apical foramen. Colour photographs were taken using an Olympus 35 mm camera attached to a stereomicroscope set at x40 magnification, and then digitized using a flatbed scanner. The cross-sectional area of the canal contents was analysed using Adobe PhotoShop. The percentage of gutta-percha, sealer or voids to the total root canal area were derived and data analysed using unpaired Student's t-test and the Mann-Whitney U-test. RESULTS: In the 30 degrees curved canals the levels had between 94 and 100% of the area filled with gutta-percha with no significant difference (P > 0.05) between the lateral condensation and single cone techniques. In the 58 degrees curved canals the levels had 92-99% of the area filled with gutta-percha, with the single cone technique having significantly (P < 0.05) more gutta-percha fill at the 2.5 mm level only. In the mesio-buccal canals of the teeth the levels had between 72 and 96% of the area filled with gutta-percha with no significant difference (P > 0.05) between the lateral condensation and single cone technique. The time for obturation was significantly (P < 0.05) greater for lateral condensation compared with the single cone technique in all groups. CONCLUSIONS: The .06 taper single cone technique was comparable with lateral condensation in the amount of gutta-percha occupying a prepared .06 tapered canal. The .06 single cone technique was faster than lateral condensation.     

Effect of irrigation solutions on the filling of lateral root canals

Abstract An in vitro study involving 66 single–rooted human teeth was performed. The teeth were divided into 3 groups: control group, root canals instrumented and irrigated with distilled water; experimental group A, root canals instrumented and irrigated with 15% EDTA; and experimental group B, root canals instrumented and irrigated with 5% sodium hypochlorite. All canals were filled with laterally condensed gutta-percha and Diaket® A. Radiographs were taken mesiodistally and buccolingually and the number of lateral canals filled in the various teeth was counted. The group treated with 15% EDTA showed a significantly larger number of filled lateral canals than the groups irrigated with distilled water or sodium hypochlorite.     

Homogeneity and adaptation of a new gutta-percha paste to root canal walls

A new flowable root canal filling material (GuttaFlow) was tested. Under simulated clinical conditions, the middle and coronal thirds of 90 human teeth with 169 root canals were shaped with 6% taper rotary HERO instruments and the apical third with rotary LightSpeed instruments. The root canals were divided into three similar groups and were filled with GuttaFlow (GF), conventional cold laterally condensed gutta-percha (LC), and warm vertically condensed gutta-percha (VC). Roots were sectioned at five levels, digitally photographed and traced. The percentage of voids area showed a statistically significant difference between GF and both LC and VC [GF 1.9% (95% CI = 1.4-2.4), LC 4.4% (95% CI = 2.2-6.6), VC 6.8% (95% CI = 5.4-8.1)]. The frequency of voids was significantly different between all groups [GF 37% (95% CI = 34%-40), LC 10% (95% CI = 8-12), VC 22% (95% CI = 19-24)]. In most sections, GuttaFlow completely filled the prepared root canal, but small voids were frequently present within the core of the filling material.     

不同封闭剂对根管壁抗折力的影响

目的:比较经过完善预备后的根管选用不同封闭剂根充对管壁抗折力的影响。方法:将30颗人尖牙随机分为二个实验组和一个对照组,每组10颗。从牙颈部截去牙冠后进行根管预备。组1以Ultra为封闭剂;组2以Endofil为封闭剂,均采用冷侧压方法充填。组3根管预备后不充填。所有标本进行抗剪切强度试验。结果:组3与其它二组间有显著性差异(P<0.01),抗折应力值最低(126.1819MPa);组1和组2之间有显著性差异(P<0.01),其抗折应力值最大(153.4974MPa)。结论:预备后不充填的根管抗折力,明显低于完善根管治疗组;使用Ultra封闭剂根充后的管壁抗折力,明显强于Endofil组。     

GuttaFlow充填系统进行根管充填的临床疗效观察

目的：观察GuttaFlow充填系统充填根管的临床疗效。方法：将急、慢性根尖周炎或急、慢性牙髓炎患者的120个患牙,随机分成两组。根管预备后分别用氧化锌丁香油糊剂加牙胶尖的冷侧压法（对照组）或GuttaFlow充填技术加牙胶尖（实验组）进行根管充填。根充后即刻拍X线牙片评价根充效果,术后1周及半年评价其临床疗效。结果：两组病例根充后X线显示充填效果有统计学差异（P〈0.05）,随访半年的临床成功率无统计学差异（P〉0.05）。结论：GuttaFlow充填系统是一种高效、简便的根管充填技术,但是远期疗效还有待于进一步观察。     

The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

AIM: The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. METHODOLOGY: Roots of 40 mandibular incisors,12 mm in length, were divided into two groups and instrumented using a balanced force technique and obturated by vertically compacted warm gutta-percha. In one group sealer was used when back-filling the root canal with the Obtura System. The other group was also back-filled with the Obtura System but without sealer. The apical 4 mm of each root filling was removed by root-end resection and root-end cavity preparation. Fluid transport along the 7 mm of remaining root filling was measured. After the leakage test, horizontal sections were cut at a level 3 mm from the apical end of the remaining root filling. The cross sectional area of the canal and gutta-percha was measured using an image analysis program. The quality of the remaining root fillings was also evaluated by calculating the percentage of gutta-percha filled canal area. RESULTS: In total, 27 (67%) out of the 40 roots demonstrated leakage. No significant difference was found between the two groups (P = 0.265). In the cross-sections the bucco-lingual canal diameter was up to 2.6 mm long (mean 1.6 mm). The average percentage of gutta-percha filled canal area was 85.6%. Warm gutta-percha could not obturate areas where debris remained after instrumentation. CONCLUSIONS: The quality of the root fillings in mandibular incisors was poor, probably because the unprepared recesses of oval canals were not clean.     

手用Protaper预备根管后注射式热塑牙胶充填系统充填效果的观察

目的观察Protaper手用法预备的后牙根管使用注射式热塑牙胶充填系统(Ultrafil-3D)充填的效果。方法10颗离体人上颌磨牙,开髓拔髓,截冠并截除腭根,按照Protaper的使用要求对颊根进行根管预备,均至F2(相当于主尖锉为25#K-file),测量根尖孔直径,干燥根管,涂布封闭剂(Roekoseal),Ultrafil-3D(Endoset)牙胶充填根管,记录注射针头进入的最大深度,直接观察超充情况,然后X线片评价整体的充填效果。结果①20个根管中有8个出现少量牙胶(伴封闭剂)超充,9个出现单纯的封闭剂超充;②根尖孔直径均≤0.25mm,注射针头距根尖孔的距离(L)均在8～10mm,牙胶超充组与无牙胶超充组差异无显著性(P>0.05)。③X线片显示牙胶未见欠充,与管壁未见明显空隙,可充填进入侧支根管。结论使用Protaper预备根管简便快速,根管形态好,有可能出现牙胶超充,但超出量较少,根管能获得整体良好的三维充填效果。     

The sealing ability of injection-moulded thermoplasticized gutta-percha

The root canals of 120 single rooted teeth were prepared with files and then divided randomly into twelve subgroups. Four operators each filled three of these subgroups, one group with laterally condensed gutta-percha, one group with thermoplasticized gutta-percha with sealer and one group with thermoplasticized gutta-percha without sealer. The fillings were assessed radiographically and a dye penetration test was used to investigate the leakage. The lowest leakage values were found in those canals filled with laterally condensed gutta-percha. The sealing ability of thermoplasticized gutta-percha was enhanced by the use of a sealer. There was greater variation between operators in those groups where thermoplasticized gutta-percha was used.     

Fluid transport and bacterial penetration along root canal fillings

Convective transport of water from the coronal to the apical end of obturated root canals was determined by the movement of an air bubble in a capillary glass tube connected to the apex of the experimental root section using a headspace pressure of 120 kPa (1.2 atm). Water transport through existing voids in the obturated canals could be measured reproducibly in this way. The root canals of 60 human maxillary canines were filled with gutta-percha and sealer by the cold lateral condensation technique. Thirty of these were first exposed to a small motile bacterium, Pseudomonas aeruginosa, growing in a reservoir at the coronal end of each root. After 50 days, two specimens allowed penetration of bacteria to a reservoir at the apical end. All the roots were then assessed quantitatively for convective transport of water. The results were divided into three defined categories: 39 obturated canals were in the‘bacteria tight’category, 14 canals in the 'slight leakage’and 7 canals in the‘gross leakage’category. The two specimens that showed bacterial penetration fell into the slight and gross leakage categories. The previous test for bacterial passage did not statistically influence the fluid transport pattern of these roots which was measured subsequently. These findings indicate that fluids transport through obturated root canals, most of which do not allow the passage of bacteria.     

Vertical root fractures in curved roots under simulated clinical conditions

The purpose of this study was to determine the incidence of vertical root fractures in the mesial roots of extracted human mandibular molars that were endodontically prepared by hand or ultrasonic instrumentation and obturated with laterally condensed gutta-percha and sealer using finger and hand spreaders. One-hundred twenty mesiofacial canals were prepared by hand or ultrasonic instrumentation. After placing the teeth in a simulated alveolus, they were obturated by laterally condensing gutta-percha and sealer with B-finger or D11T hand spreaders. Teeth were obturated using forces in the range of 1 to 3 kg or 4.5 to 7.5 kg. Three teeth obturated with the D11T hand spreader using 7.0 to 7.3 kg of force demonstrated vertical root fractures. The results suggest that in vitro the range of forces reported as most commonly used by endodontists to laterally condense gutta-percha (1.0 to 3.0 kg) and those of a higher magnitude up to 4.9 kg are safe and will not result in vertical root fractures of mesial roots of mandibular molars.     

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。     

The sealing ability of amalgam used as a retrograde root filling in endodontic surgery

A dye penetration technique was used to investigate the sealing ability of amalgam retrograde root fillings in vitro. A factorial design was employed to determine the effect of amalgam fillings of 1, 2 and 4 mm in length with and without prior filling of the canals with gutta-percha. The results were compared with a group of teeth filled with laterally condensed gutta-percha alone and another with laterally condensed gutta-percha plus root resection but with no retrograde filling. It was concluded that increasing the length of the amalgam filling did not improve the seal, that prior filling of the canal did not improve the seal, that retrograde root fillings were no worse than laterally condensed gutta-percha alone and that root resection of teeth filled with laterally condensed gutta-percha without retrograde filling was no worse than those filled with laterally condensed gutta-percha without root resection or retrograde root filling.     

不同根管处理方法对根管壁抗折力影响的研究

目的　比较预备与不预备的根管以及预备后充填与不充填的根管抗折力。方法　将 30颗人尖牙随机分为 2个实验组和 1个对照组 ,每组 10颗。实验组从牙颈部截去牙冠后进行根管预备。第 1组以Ultra为封闭剂 ,采用冷侧压方法充填 ;第2组根管预备后不充填 ;第 3组根管不作任何处理。所有标本进行抗剪切强度试验。结果　第 2组与其他 2组间差异有显著性 (P <0 .0 0 1) ,抗折应力值最低 (12 6 .182MPa) ;第 1组抗折应力值最大 (15 3.4 97MPa) ;第 1组和第 3组之间无统计学差异 (P>0 .0 5 )。结论　预备后不充填的根管抗折力低于未处理组和完善根管治疗组。使用封闭剂根充后的管壁抗折力增强。     

H锉联合回旋手机与ProFile镍钛系统拆除根充牙胶能力的比较研究

目的比较H锉联合同旋手机与ProFile镍钛系统在进行根管再治疗时拆除根管充填物的能力。方法选取24颗离体下前牙常规根管治疗后随机分为2组(每组12颗),分别采用H锉联合回旋手机和ProFile镍钛系统进行根充物的拆除,每组都使用氯仿。记录到达工作长度牙数、到达工作长度用时、根充物推出根尖孔牙数、发生并发症牙数及器械损耗数。最后纵劈牙齿,统计根管内残余充填物量。实验结果采用t检验和卡方检验。结果H锉联合回旋手机组到达根尖工作长度用时较短,与ProFile组间存在显著性差异(P< 0．01);两组根管内都有充填物残余;PorFile组在拆充过程中较少发生根充物被推出根尖孔的情况;ProFik器械的损耗率较高。结论ProFile器械不适用于拆除根充牙胶。