The effect of standard or serial preparation on single cone obturations

Summary. This leakage study, in vitro , used methylene blue dye as a marker to detect the extent of apical fluid penetration after buccal roots from maxillary first bicuspids were instrumented either by the standard technique or serially, and obturated with laterally condensed gutta-percha and sealer, a single gutta-percha master cone and sealer, or sealer alone. The linear extent of dye penetration was measured after the roots were split longitudinally. In this study the laterally condensed gutta-percha and sealer technique resulted in the least apical penetration of dye. The single gutta-percha cone and sealer technique groups had less dye penetration than the groups where obturation was with sealer alone. The use of the standard or serial technique of preparing canals resulted in no significant difference in the quality of obturation using a single gutta-percha cone with sealer or using sealer alone.     

Evaluation of the apical seal in root canals prepared with a new rotary system and obturated with a methacrylate based endodontic sealer: an in vitro study

The purpose of this study was to evaluate in vitro the apical seal of root canals prepared with a new rotary system, Anatomic Endodontic Technology (AET) and filled with a methacrylate based endodontic sealer and a single gutta-percha cone and a lateral condensation technique, using the methacrylate based endodontic sealer/filler or Grossman's cement. The root canals of 45 freshly extracted human maxillary anterior teeth were prepared and then randomly assigned to three groups of 15 teeth each. After cleaning and shaping the teeth were obturated as follows: in group 1 the canals were filled with a methacrylate based sealer and a single gutta-percha cone; in group 2 the canals were filled using a lateral condensation technique with gutta-percha and the methacrylate based sealer; and in group 3, the canals were filled by means of lateral condensation of gutta-percha and Grossman's cement (control group). The specimens were stored in 100% relative humidity at 37 degrees C for 72 h, after which the coronal portion and the root surface of each tooth was covered with three layers of nail varnish and a final layer of sticky wax. After immersion in 2% methylene blue dye for 7 days, the specimens were imbedded in clear orthodontic resin and sectioned. Dye penetration was evaluated by an independent investigator using a stereo microscope. The results demonstrated that more pronounced leakage occurred in root canals obturated with the lateral condensation technique and Grossman's cement (p < 0.05). The least amount of dye leakage was observed for group 1 and 2 in which the methacrylate based sealer was used, either with a single gutta-percha cone or with lateral condensation of gutta-percha.     

5种根管充填糊剂的根管封闭能力的比较

目的：比较5种根管充填糊剂的根管封闭能力。方法：选择75个直根管的恒牙,经开髓拔髓,Mtwo镍钛根管器械预备后反复冲洗后随机分为5组,分别采用实验组1：氧化锌丁香油糊剂,实验组2：Endomethasone根管充填糊剂,实验组3：Cortisomol根管充填糊剂,实验组4：Vitapex糊剂,实验组5：AH-plus糊剂,加牙胶尖严密充填。将所有离体牙置于37℃,100%湿度的恒温箱3d后选用透明牙染色法测量微渗漏深度。结果：实验组1：（2.35±0.768）mm,实验组2：（1.78±0.548）mm,实验组3：（1.54±0.322）mm,实验组4：（3.22±0.452）mm,实验组5：（0.98±0.536）mm。各组微渗漏深度值差异有显著性（P〈0.05）。其中实验组4的微渗漏值显著高于其他各组（P〈0.05）,实验组5的微渗漏值显著低于其他各组（P〈0.05）,实验组2的微渗漏值稍高于实验组3,结果无显著差异。结论：在Mtwo镍钛器械预备下,AH-Plus糊剂充填根管可有效的减少根管微渗漏的发生,但长远疗效有待进一步的观察。     

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.     

Apical sealing efficacy of endodontic obturation techniques

Summary. This study in vitro utilized methylene blue dye to evaluate root canal apical leakage after maxillary central incisors were serially instrumented and obturated with laterally condensed guta-percha and sealer, a single fitted gutta-percha master cone and sealer, sealer alone or paste alone. The linear extent of dye penetration was measured, and the volume of dye leakage was evaluated using a dye-recovery spectrophotometric technique. Under the conditions of this study, the teeth obturated with laterally condensed gutta-percha and sealer exhibited the least leakage. The single gutta-percha cone and sealer technique had no advantage over use of sealer or paste when used alone.     

An in vitro study of the quality of root fillings in teeth obturated by lateral condensation of gutta-percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of linear apical dye penetration in teeth root filled with either laterally condensed gutta-percha or Thermafil obturators, A total of 150 teeth with single roots were included in the study. All canals were prepared using a standard step-back technique with anticurvature filing. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point, was used to divide the teeth into two experimental and two control groups. A total of eight teeth were excluded because of technical difficulties, 65 were filled with Thermafil obturators, 63 were filled with laterally condensed gutta-percha whilst 14 teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. Canal obturation with Thermafil obturators (0.7 min) was significantly quicker (P > 0.001) than lateral condensation (6.4 min). Apical extrusion of sealer and gutta-percha occurred significantly more often with Thermafil obturators but there was little difference in the technical quality of the fillings and no significant difference in dye penetration. Under the conditions of this study, Thermafil obturators proved a satisfactory alternative to lateral condensation of gutta-percha.     

An in vitro comparison of the single cone and lateral condensation techniques using ''friction-fitted'' and ''solvent dip-fitted'' primary gutta-percha cones

Extracted teeth, root-filled by single cone and lateral condensation techniques, using friction fitted and solvent (chloroform and eucalyptol) dip-fitted primary gutta-percha cones, were compared with respect to apical sealing as measured by length of dye penetration and frequency of no dye penetration. Overall, the single cone techniques were significantly more effective than lateral condensation techniques regarding length of dye penetration. The single cone techniques were not significantly different from the lateral condensation technique which employed chloroform dip-fitted primary gutta-percha cones regarding length of dye penetration. The single cone and lateral condensation techniques which utilized chloroform dip-fitted cones ranked first and second with respect to frequency of no dye penetration.     

两种根尖屏障对Ultrafil-3D系统根管充填效果的影响

目的比较主尖法及Successfil牙胶法对Ultrafil-3D系统牙胶充填根管的根尖屏障作用及其对根管充填效果的影响。方法64颗人离体单、直根管前牙,分别以主尖法及Successfil牙胶法建立根尖屏障,用三种不同粘度的Ultrafil-3D牙胶(Endoset,Firm set,Regular set)充填根管,拍摄近远中向及唇舌向X光片,2％亚甲蓝染色5天,将牙体纵劈后测量染料的线性染色长度。结果Successfil牙胶法组根管充填效果的唇舌向X-片评价较主尖法组差(P<0．001),但其微漏显著小于主尖法组(P<0．01)。结论主尖法及Successfil牙胶法均能有效阻止热塑牙胶注射时超充,Successfil牙胶法的根管充填整体效果优于主尖法。     

Thermomechanical compaction of gutta-percha. I. A comparison of several compaction procedures

Summary. The root canals of 97 extracted, single-rooted teeth were prepared and filled by thermomechanical compaction of gutta-percha and an additional 17 teeth were used unfilled as controls to observe dye penetration. By varying the size of the master gutta-percha cone, the size of the compacting instrument and the amount of gutta-percha inserted into the root canal before compaction, seven experimental groups were formed. The criteria used for judging the quality of root canal fillings were radiographic examination, dye penetration and adaptation in transverse sections. One method of using the technique proved to be superior to the other six. A significant difference from other experimental methods, however, was only found with radiographic examination and dye penetration, respectively. No significant differences were obtained when the adaptation of gutta-percha was compared; this was also the case with the combined results of the three criteria.     

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.     

In vitro evaluation of three techniques to obturate 0.06 taper canal preparations

The aim of this study was to evaluate the ability of three obturation methods to seal root canals prepared using 0.06 taper rotary instruments. Forty-five extracted human single-rooted teeth were instrumented with 0.06 taper Profile nickel-titanium rotary files and randomly divided into three experimental groups containing 15 teeth each. The first group was obturated using the System B technique with 0.06 taper standardised gutta-percha points, the second group was obturated using the System B technique with non-standardised MF gutta-percha points, the third group was obturated by cold lateral condensation technique using standardised 0.02 taper master gutta-percha points. Apical leakage of the roots was evaluated by dye penetration using a stereomicroscope after sectioning the roots. The group obturated using System B and 0.06 taper gutta-percha points showed the least dye penetration. However, the difference in the linear extent of dye penetration was not statistically significant.     

A comparison of the apical dye penetration patterns shown by methylene blue and India ink in root-filled teeth

This study compared the linear leakage patterns shown by 5% aqueous solution of methylene blue (MB) and India ink (II). One-hundred and twenty-five roots with single canals from extracted human teeth were used. The canals were cleaned and shaped using the step-back technique under copious irrigation. Three groups were arranged to receive root fillings of gutta-percha and one of three proprietary sealers using standard lateral condensation techniques: Sealapex (40 roots), Tubli-Seal (40 roots) and Ketac-Endo (20 roots). The remaining roots were used as controls: positive with gutta-percha and no sealer and negative with the apices sealed with nail varnish. The roots were randomly selected for 7-day immersion in either MB or II, then sectioned longitudinally; dye penetration was assessed using a Wild Leitz stereomicroscope. In all groups MB showed more penetration than II. The results were statistically significant at the P= 0.01 level, with the exception of the positive control groups. Negative controls showed no penetration. It is concluded that MB, which has a low molecular weight penetrated more deeply along root canal fillings than II, which has a large particle size.     

纳米根管充填材料根尖封闭能力的实验研究

目的 观察纳米材料根充后根尖微渗漏请况，评价其根尖封闭能力。方法 30颗离体单根管牙牙根，随机分为三组，每组10个，预备完成的根管用牙胶尖和一种根管糊荆、采用侧方加压法进行充填。根据染料在牙根中的渗入深度，评价根尖微渗漏情况。结果 三种材料的根尖微渗漏有显著差异（P〈0．01）；n-ZO组的根尖微渗漏最小，n-HA组次之，ZOE组最大。结论 纳米氧化锌糊剂和纳米羟磷灰石糊剂具有良好的根尖封闭性，可以作为根管封闭剞用于根管充填。     

Apical leakage associated with three obturation techniques in large and small root canals

Abstract. This study evaluated the apical leakage associated with three methods of root canal obturation; these were laterally condensed gutta-percha with and without custom-fined master cones and a single silver point technique. Two different sized canals were used. An analysis of linear dye leakage was performed for large canals and a technique of dye recovery and spectrophotometric analysis was used to examine the volume of leakage in both large and small canals.
Laterally condensed gutta-percha with custom-fitted master cones resulted in less volume of apical leakage than did non-custom-fitted laterally condensed gutta-percha or silver cones.     

The effect of varnish and pit and fissure sealants on the sealing capacity of retrofilling techniques

Freshly extracted teeth with single canals were instrumented and filled with laterally condensed gutta-percha and sealer. After obturation, the tooth apices were treated with various retrograde techniques. The sealing ability of these techniques, namely laterally condensed gutta-percha, heat-sealed gutta-percha, and silver amalgam retrofilling, was compared on the basis of dye penetration. The apical foramen of the treated canals was then coated with different sealing materials--HelioSeal (light-activated sealant), Delton pit and fissure sealant (chemically activated sealant), and varnish--to examine their effect on the leakage resistance of these materials. Statistical analysis indicated that laterally condensed gutta-percha, as well as retrograde amalgam filling, produced a statistically significantly better seal than heat-sealed gutta-percha. Coating of the apical foramen with different sealing materials showed that HelioSeal had significantly improved the sealing capacity of all the materials tested at each time period. Delton pit and fissure sealant did not increase the sealing ability in the first week. However, this material has significantly improved the sealing ability after the first week. On the other hand, sealing of the apical foramen with varnish did not produce any significant change in the sealing capacity of the filling materials. Finally, dye penetration around all the filling and retrofilling materials, in the presence or absence of the apical seal, continued and increased with time. However, root canals sealed with Helioseal consistently showed the least amount of apical leakage of all the canals tested.     

Evaluation of dowel space preparation on the apical seal using an image processing system

The effect of post preparation on the apical seal of endodontically treated specimens was studied. The canals prepared in bovine bone were instrumented and obturated using five obturation techniques: the silver point technique, the lateral condensation of gutta-percha technique, the warm vertical condensation of gutta-percha technique, the Hygenic Ultrafil injection system and the Obtura technique. In addition to these five control groups, the five experimental groups were also subjected to post preparation. In the latter group, the gutta-percha was removed with an engine-driven root canal reamer 48 hours after obturation. Both the control and experimental groups were suspended in a 0.5 per cent crystal violet solution for 48 hours. After dye penetration, the specimens were immersed in liquid nitrogen and then split longitudinally. Linear measurements of the resultant apical dye leakage were determined by image processing. For each obturation technique, all specimens in both the control and experimental groups were recorded if they showed leakage. Using Fisher's exact probability test, it was shown that there was no significant difference between the obturation techniques used.     

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.     

Apical dye penetration with four root canal sealers and gutta-percha using longitudinal sectioning.

The purpose of this study was to compare the level of apical dye penetration when different sealers were used with lateral condensation of gutta-percha. Fifty teeth with single root canals were biomechanically prepared using the step-back technique and irrigation with 15% ethylenediaminetetraacetic acid with cetrimide and 1% NaOCl solutions. The teeth were divided into five groups of 10 teeth each. The control group root canals were filled with laterally condensed gutta-percha without sealer and the other four groups were filled with laterally condensed gutta-percha and either Apexit, Sealapex, Tubli-Seal, or AH-26 sealer. After storage in 100% humidity at 37 degrees C for 48 h, the root surfaces were coated with nail varnish (except at the apex), placed in 2% methylene blue dye solution, and centrifuged at 30 x g for 3 min. The roots were sectioned longitudinally to determine the following mean levels of dye penetration: AH-26, 0.48 mm; Apexit, 1.33 mm; Sealapex, 4.59 mm; Tubli-Seal, 5.58 mm; and gutta-percha alone, 7.99 mm. This study demonstrated that a root canal sealer should be used in conjunction with laterally condensed gutta-percha and that AH-26 sealer had significantly less dye penetration than the other three sealers while Apexit had significantly less dye penetration than Sealapex and Tubli-Seal. There was no significant difference between Sealapex and Tubli-Seal.     

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.     

手用ProTaper镍钛器械根管预备后不同充填方法的效果研究

目的:比较手用ProTaper镍钛器械预备根管后不同方法充填后的根尖封闭能力。方法:将手用ProTaper器械预备的45个上颌磨牙单根管牙根,随机分为3组,每组15个。第1组:侧方加压法配合ISO标准牙胶充填;第2组:单尖法配合非ISO标准牙胶充填;第3组:热牙胶垂直加压法配合非ISO标准牙胶充填。牙根经过染色、透明,镜下测量染料渗入深度。结果:第1组和第3组的染料渗入的深度小于第2组,有统计学意义(P<0.05)。结论:手用ProTaper器械预备后的根管采用热牙胶垂直加压法 非ISO牙胶或侧方加压法 ISO牙胶可以获得良好的根尖封闭。