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目的对比评价三种根管充填技术的根尖封闭能力。方法收集2011年10月至2012年5月中国医科大学附属口腔医院口腔颌面外科门诊因正畸或牙周病拔除的新鲜离体单根管牙34颗,根管清理后用机用ProTaDer镍钛锉经Crown—Down技术预备,然后随机分为A、B、C三组。A组（11颗）采用冷牙胶侧方加压充填技术充填根管,B组（10颗）采用超声侧方加压充填技术充填根管,c组（13颗）采用连续波热牙胶垂直充填技术充填根管。所有实验牙均使用AHPlus根充糊剂。根管充填后的各组实验牙采用染料渗透法检测根尖微渗漏的发生情况,体式显微镜下测量自根尖孔向冠方的染料渗透长度,采用SPSS11．5统计软件包对测量数据进行分析。结果A组与B、c组的根尖微渗漏数值间差异有统计学意义（P〈0．05）,B组与c组的根尖微渗漏数值间差异无统计学意义（P〉0．05）。结论超声侧方加压充填技术和连续波热牙胶垂直充填技术的根管封闭能力优于冷牙胶侧方加压技术,而前两种充填技术的根管封闭能力无明显差别。     

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。     

不同锥度牙胶尖热垂直加压法根管充填的临床疗效分析

目的研究采用不同锥度牙胶尖热垂直加压法行根管充填的临床X线片评价及术后1年的临床疗效。方法选择上颌前牙单、直根管患牙40颗为研究对象,采用Hero 642机用镍钛锉预备至0.06锥度30号锉,随机分为2组,每组20颗患牙。分别使用0.02锥度和0.06锥度牙胶尖采用热垂直加压法充填根管。对术后即刻X线片进行2组患牙根管充填质量、侧支根管充填及超填情况的比较;并比较2组患牙术后1年的临床疗效。结果0.02锥度组与0.06锥度组根管充填质量、侧支根管充填及超填情况没有明显差异。术后1年复查,0.02锥度组与0.06锥度组的治疗成功率一致,但0.06锥度组病变愈合趋势快于0.02锥度组。结论对于镍钛旋转器械预备的较大锥度单、直根管,采用热牙胶垂直加压法行根管充填,使用与根管预备锥度相一致的大锥度牙胶尖能够提高根管治疗的临床疗效。     

热塑牙胶充填根管临床观察

目的：观察连续波热塑牙胶注射法充填根管的临床效果.方法：选择360例根管治疗患者,共380颗牙,其中240颗牙用热塑牙胶注射充填仪做连续波热塑牙胶充填根管,140颗牙用常规冷牙胶侧方加压充填根管,通过X线片比较两组病例的充填质量并比较两组病例间每根管根充需用时间.结果：X线片显示连续波热塑牙胶充填组欠填率1.67％,超填率2.91％,恰填率95.41％,冷牙胶侧压充填组欠填率8.57％,超填率2.85％,恰填率88.57％,比较两组间欠填率与恰填率有统计学差异（P＜0.05）,连续波热塑牙胶充填组平均每根管根充时间8 min.冷牙胶侧压组充填平均每根管根充时间12 min.连续波热塑牙胶充填组缩短根充时间30％.结论：连续波热塑牙胶充填术比冷牙胶侧方加压充填术根管充填质量更高且节约根充时间,提高了工作效率.     

Apical sealing ability of 2 epoxy resin-based sealers used with root canal obturation techniques based on warm gutta-percha compared to cold lateral condensation.

OBJECTIVE: To evaluate the apical sealing ability of 2 epoxy resin-based root canal sealers used with 2 different warm gutta-percha obturation techniques and cold lateral condensation. METHOD AND MATERIALS: The root canals of 72 freshly extracted single-root incisors were prepared and randomly assigned to 6 experimental groups. Root canal fillings were performed using either cold lateral condensation, warm vertical condensation, or Thermafil obturators with EndoRez or AH Plus as sealer. After root canal filling, the teeth were stored in 5% methylene blue solution for 7 days. Linear dye penetration was measured in bisected specimens by a calibrated investigator using a light microscope. RESULTS: Statistical analysis revealed significantly higher penetration depths in groups where EndoRez was used (P < .05, Tukey test). Regarding the different obturation techniques, the least amount of dye penetration was observed for AH Plus and EndoRez when warm vertical condensation was used. CONCLUSION: The results of this study indicate that the apical sealing ability of EndoRez is not as effective as that of AH Plus. Thermafil obturators and warm vertical condensation achieved seals with low dye penetration depth. The use of these techniques might decrease the risk of apical leakage.     

The apical sealing ability of a new root canal filling material

PURPOSE: To assess the apical sealing property of a new root canal filling material, Epiphany. METHODS: Seventy extracted maxillary and mandibular single-rooted teeth were used. They were randomly divided into three groups and obturated by lateral condensation with gutta-percha and AH 26/AH Plus sealers and Resilon core material and Epiphany sealer. Apical leakage was measured by the fluid-transport method. RESULTS: The differences in leakage among gutta-percha with AH 26, gutta-percha with AH Plus, and Resilon with Epiphany were statistically significant (P < 0.05). The teeth filled with gutta-percha/AH 26 displayed the most apical leakage. There were no differences between the Resilon/Epiphany and gutta-percha/AH Plus groups (P > 0.05).     

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.     

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.     

The long-term sealing ability of an epoxy resin root canal sealer used with five gutta percha obturation techniques

AIM: The aim of the present study was to evaluate the long-term sealing ability (both apical and coronal) of an epoxy resin root canal sealer (AH26) when used with different gutta-percha obturation techniques. METHODOLOGY: Straight single-rooted teeth with mature apices were divided into 10 groups of 75 teeth and one group of 40 control teeth. Root canals were prepared according to the crown-down/step-back technique and using both 2.5% sodium hypochlorite and an EDTA paste. Root canals were obturated using cold lateral condensation, warm vertical condensation and hybrid condensation of gutta-percha; and with Thermafil and Soft-Core obturators. AH26 was used as the sealer in all cases. After root canal filling, each group was divided into five individual groups of 15 teeth. The first group of 15 teeth was kept for 1 day, the second for 1 week, the third for 4 months, the fourth for 6 months and the fifth for 12 months at 37 degrees C in vacutainers in 80% relative humidity. The teeth were immersed in India ink for 90 h, each root was split and sectioned longitudinally, and the maximum extent of leakage was measured using a stereomicroscope at x6 magnification. RESULTS: Leakage occurred whatever filling technique was combined with AH26. The number of teeth with gross leakage increased with time up to 4 months, but did not appear to increase between 6 and 12 months storage. The degree of apical leakage and the number of leaking teeth in the Soft-Core obturator groups was significantly higher than all four other gutta-percha obturation techniques. Up to 4 months the degree of coronal leakage and the number of leaking teeth in the Thermafil groups was significantly higher than the other gutta-percha obturation techniques, except for Soft-Core. In the Soft-Core obturator groups the degree of coronal leakage and the number of leaking teeth was significantly higher than the other gutta-percha obturation techniques, except for Thermafil at all evaluation times. CONCLUSION: The hybrid gutta-percha condensation technique was superior to the other four obturation techniques in respect of apical leakage. Coronal leakage was significantly greater during the first 4 months for the Thermafil system as compared to the three condensation techniques; coronal leakage was significantly greater at all time periods for the Soft-Core system. There were no significant differences between the Thermafil and the Soft-core system.     

Evaluation of intracanal sealer distribution with 5 different obturation techniques.

OBJECTIVE: The aim of this study was to determine the distribution patterns of sealer relative to the gutta-percha and the canal wall following the use of different obturation techniques: vertical condensation, Obtura II, System B, SimpliFill, and Thermafil Plus; lateral condensation was used as a comparison. METHODS AND MATERIALS: One hundred five extracted single-rooted teeth were divided into 5 groups of 20 according to obturation technique, with 5 in the lateral condensation group. Instrumentation technique and sealer selection were based on the manufacturer's recommendations. Following obturation, teeth were stored for 4 months at 37 degrees C in 100% humidity. Roots were split longitudinally and halves were examined under a stereomicroscope (x 10) to determine the amount of sealer coverage between the gutta-percha and canal wall. Coverage was categorized as slight (0 to 1/3), low partial (1/3 to 2/3), high partial (2/3 to 9/10), and complete (9/10 to 10/10). RESULTS: Different techniques showed different patterns, but no obturation technique had sealer forming a continuous layer between the gutta-percha and canal wall. The vertical condensation group generally had low partial coverage. Obtura II was the only group to have slight coverage, which occurred in the coronal half. Coronal and apical halves in both the System B and Thermafil Plus groups had the most samples with high partial coverage. SimpliFill had the most samples with complete coverage in both the coronal and the apical portions. All lateral condensation samples showed low partial coverage. CONCLUSION: Sealer distribution patterns were incomplete and inconsistent, regardless of the obturation technique. No technique had sealer forming a continuous layer between the gutta-percha and canal wall.     

Apical leakage of Resilon obturation material

AIM: The aim of this study was to assess the apical sealing ability of Resilon obturation material. METHODS AND MATERIALS: Forty-two single rooted extracted human teeth were selected and randomly divided into three groups. They were obturated using lateral condensation with gutta-percha and AH 26/AH plus and Resilon; also, 12 root canals were used as control groups. The apical leakage was measured using the dye penetration methodology. RESULTS: The teeth filled with gutta-percha and AH 26 displayed the most apical leakage. The least apical leakage was shown with Resilon. DISCUSSION: The differences in leakage among the groups, gutta-percha with AH 26 (2.4 mm, SD:1.87), gutta-percha with AH plus (2.1 mm, SD: 1.69), and Resilon (1.7 mm, SD:1.32), were statistically significant (p< 0.001). CONCLUSION: Based on the data of this study, all groups produced a satisfactory seal. However, Resilon and Epiphany sealer showed the least apical leakage.     

Push-out bond strength of a new endodontic obturation system (Resilon/Epiphany)

Endodontic sealers should demonstrate adhesive properties to dentin to reach the objectives of the obturation of the canal space and seal the canal space both apically and coronally, thus decreasing the chance of endodontic treatment failure. Adhesion to dentin with bonding to the tooth structure in the canal may provide greater resistance to tooth fracture and greater clinical longevity of an endodontically treated tooth. In this study, human single-canal canines were endodontically treated and obturated with two different endodontic obturation systems (Epiphany/Resilon system and gutta-percha/AH 26). Thirty roots (divided into two groups) were horizontally sliced for a push-out strength test, which was performed from apical to coronal in the universal testing machine. Differences in push-out bond strength between the two different material systems were obtained using repeated measures analysis of variance on ranks. Gutta-percha had significantly higher push-out bond strength than Epiphany (p<0.0001).     

四种根管充填法对根管密合度的实验研究

目的：使用新型根管糊剂，比较四种充填方法对根管密合度的影响，从而指导临床根管充填法的选择。方法：在离体前牙上行根管预备及根管充填，而后用印度墨水染色法在显微镜下比较充填效果。结果：显微镜下观察糊剂加牙胶的侧方加压充填法组和单纯使用糊剂的机用螺旋充填法组有较好的封闭性能。结论：本实验为新型糊剂的合理应用提供了可靠的参考依据。     

Literature survey of apexification in connection with three cases

Endodontic treatment of three non-vital immature teeth is discussed. According Moorrees et al. root formation was in the stage two, six and four respectively. After access to the root canal, removing necrotic pulp and effective chemo-mechanical cleansing, Ca(OH)2 paste was used as a temporary filling material in each case. In two cases after closing the apical opening, permanent obturation was performed with half heated gutta-percha and lateral condensation to obtain a good seal. In one case permanent filling of the canal occurred with gutta-percha and AH26 as a sealer. In the first case two years, in the second case five years after obturation of the root canal with gutta-percha, periapical healing was evident in the control radiograph. In the third case using gutta-percha with AH26 as a sealer after two years new periapical lesion has developed. On the bases of literature data and our experiences in the case of non-vital immature teeth. Ca(OH)2 paste is the best temporary filling material to induce apexification process, and the half heated gutta-percha obturation is the most suitable permanent root filling material.     

Fracture resistance of roots filled with three different obturation techniques

Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was performed; in group 3, the obturation was done with AH 26 + gutta-percha; in group 4, with AH 26 + BeeFill and in group 5, AH 26 + a Thermafil obturator was used. All the roots were mounted vertically in copper rings and filled with acrylic resin, exposing 8 mm of the coronal part. A universal testing machine was used for the strength test. Results: The results were analyzed using the one-way ANOVA test. The significance between the groups was tested with Temhane’s T2 test. The results indicate that instrumentation of root canals had a significant effect on fracture resistance (p<0.05). In addition, there were no differences between the root canal obturation techniques; furthermore, these techniques did not create a statistically important resistance to vertical fracture (p>0.05). Conclusions: The results suggest that instrumentation of root canals significantly weakens the tooth structure to fracture and the root canal obturation techniques that are used are not able to form reinforcement. Key words:AH 26, obturation technique, vertical fracture.     

An investigation into the apical leakage of root-filled teeth prepared for a post crown

The effect of post canal preparation on the apical seal of endodontically treated teeth was studied in vitro. Single-rooted teeth with mature apices were prepared chemomechanically and obturated with gutta-percha and sealer using one of four techniques: cold lateral condensation, thermo-mechanical compaction, thermomechanical compaction as an adjunct to lateral condensation (hybrid technique), or lateral condensation using an electrically heated spreader, the Endotec. Forty-eight hours after obturation each group of 15 teeth was prepared to accept a post crown. Five teeth in each group were left unprepared as controls. The extent of apical leakage was then determined using a dye, Indian ink, and a clearing technique that rendered the teeth transparent. Linear measurement of the dye penetration was recorded. The results showed that, for each method of obturation, there were no statistically significant differences between the teeth prepared for a post and the unprepared controls. There were no significant differences in leakage between the different groups that had been prepared for a post, or between the control groups.     

Effects of new adhesive resin root canal filling materials on vertical root fractures

The aim of this study was to compare the fracture resistance of roots following root canal therapy using the RC Sealer system, the Epiphany system and the conventional system of gutta-percha and Sealapex. Fifty-six maxillary central incisors were divided into eight groups of seven teeth each, according to master apical file size and obturation systems. Obturation materials in the root canal were vertically loaded using a universal testing machine. Fracture loads were analysed by anova and Tukey comparison, and fracture patterns were analysed with ordinal logistic regression. Master apical file size 80 had a significantly lower fracture load than size 40 (P < 0.05). The groups obturated using the Resilon Cone and the Epiphany Sealer had significantly lower fracture loads than the other groups (P < 0.05). There was no significant improvement in resistance to vertical root fractures using the examined adhesive resin root canal filling systems, compared with conventional gutta-percha and sealer.     

Outcome of endodontic treatment of teeth filled using lateral condensation versus vertical compaction (Schilder's technique)

The purpose of this prospective clinical and radiographic investigation was to assess the treatment results following endodontic therapy of teeth filled with lateral condensation versus teeth filled with vertical compaction of warm gutta-percha. A total of 290 patients were treated using the standardized step-back technique for canal preparation, which were filled with either lateral condensation or vertical compaction in one single session. Five years later, the treatment results were assessed clinically and radiographically and related to the type of the obturation technique using Chi-square analysis. Of the 340 teeth that were reexamined, 160 teeth were filled with lateral condensation, and 180 teeth were filled with vertical condensation. The results showed a significantly higher success rate for the vertical compaction versus the lateral condensation technique of teeth presented with preoperative periapical lesions P<0.04. Regardless of the preoperative periapical status of the teeth, no statistically significant difference was found between the two techniques. The overall success rate of both filling techniques was 80.3%.     

The use of glass ionomer as a root canal sealer—a pilot study

The use of a resin-based glass ionomer as an endodontic sealer was studied in vitro. The root canals of extracted single-rooted human teeth with mature apices were prepared using a stepback technique. Subsequently, the smear layer was removed with 40% citric acid and the canals obturated using lateral condensation of cold gutta-percha and a resin-based glass ionomer as the sealer. The relationship between the sealer and the wall of the root canal was studied using scanning electron microscopy. The shear bond strength of gutta-percha to this glass ionomer was also determined. Finally, the uptake of fluoride into the wall of the root canal was studied using scanning electron microprobe analysis after storage for 2 weeks, 1 month and 3 months following root filling with gutta-percha and glass ionomer cement. The results showed that removal of the smear layer allowed the sealer to enter some of the dentinal tubules. This was observed most frequently in the middle third of the root canal, where there was good adaptation of the sealer. The shear bond strength of gutta-percha to the glass ionomer sealer was not significantly different from that obtained between gutta-percha and a proprietary zinc oxide-eugenol endodontic sealer. The concentration of fluoride in the dentine in the coronal part of the root canal increased after obturation with gutta-percha and the glass ionomer sealer at every time interval. The increase in fluoride concentration varied widely between teeth. It is concluded that a resin-based glass ionomer cement may have potential as a root canal sealer.     

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.