Comparison of cold lateral compaction and continuous wave of obturation techniques following manual or rotary instrumentation

AIM: To compare different combinations of root canal preparation and obturation technique. METHODOLOGY: A total of 48 freshly extracted human maxillary central incisors were divided into two identical groups on the basis of root canal length and apical diameter. The root canals were prepared by manual crown-down pressureless technique or with a rotary system (ProFile; Dentsply Maillefer, Ballaigues, Switzerland) in a crown-down technique. The coronal diameter and apical size of the root canals were standardized in both preparation techniques. Each main group was then divided into two subgroups and obturated with either cold lateral compaction or continuous wave of obturation with System B (EIE-Analytic Technology, Orange, CA, USA). The distribution of filling material in each canal was assessed by stereomicroscopic examination of eight cross-sections on each tooth. Areas of sealer, gutta-percha and voids were measured on the digital images of a total of 384 samples. Manipulation time and apical extrusion for each group was also determined. Data were statistically analysed using Kruskal-Wallis, anova (Bonferroni/Dunn) or Student's t-test. RESULTS: The percentage of sealer, gutta-percha and voids area between the obturation techniques was not significantly different (P > 0.05). Continuous wave groups had significantly more apical extrusion of sealer (P < 0.05), while none of the obturation techniques had gutta-percha extrusion. Rotary instrumentation was significantly faster than the manual technique (P < 0.05); continuous wave obturation was significantly faster than lateral compaction (P < 0.05). Total manipulation time in the rotary/continuous wave group was significantly shorter than the other groups (P < 0.0001). CONCLUSION: The distribution of filling materials was similar in all combinations of instrumentation and obturation techniques. The continuous wave technique was faster than lateral compaction and it extruded more sealer.     

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.     

Comparison of two vertical condensation obturation techniques: Touch ''n Heat modified and System B

AIM: The aims of this study were firstly to compare the area of canal occupied by gutta-percha, sealer or voids using the System B heating device with that obtained by a modified vertical condensation technique using the Touch 'n Heat: and secondly to compare the temperature changes at the root canal wall and external root surface during obturation with the above techniques. METHODOLOGY: Forty-five resin blocks, each with a standardized, simulated, prepared main root canal and five lateral canals, were assigned to three equal experimental groups. The canals were obturated using either the System B technique at two different temperature settings, or vertical condensation with a Touch 'n Heat instrument as the heat source. A heat transfer model was used to simultaneously record internal and external root surface temperature elevations during obturation by the three techniques. Data were analysed using unpaired Student's t-test and Mann-Whitney U-test. RESULTS: Both obturation techniques produced root fillings consisting of over 90% gutta-percha at most levels, although the percentages of sealer and voids 2-3 mm from the working length following System B obturation were higher than those found following modified vertical condensation. Modified vertical condensation resulted in more gutta-percha in lateral canals. Obturation was accomplished more quickly using the System B, and temperature elevations produced during obturation with the System B were significantly less (P < 0.001) than with vertical condensation. An elevation of external root surface temperature by more than 10 degrees C occurred during vertical condensation. CONCLUSIONS: The results suggest that the System B may produce an acceptable obturation and that the use of a Touch 'n Heat source during vertical condensation may result in damage to the periodontium.     

In vivo performance of the new non-instrumentation technology (NIT) for root canal obturation

AIM: The aim of this in vivo study was to compare the radiographic quality of root fillings performed by the NIT-obturation method versus conventional mechanical obturation. METHODOLOGY: Sixty-six patients needing root canal treatment participated in this study. The treatments were performed by three private practitioners. The root canals were instrumented with K-Flexofiles to a master apical file between sizes 25 and 60, followed by step-back flaring up to size 70. Copious irrigation was used throughout the instrumentation procedure with NaOCl (3%). The teeth were obturated either by lateral condensation, the McSpadden technique (control) or by the new non-instrumentation technology (NIT) with and without using gutta-percha points. In the NIT method, a low pressure was created within the tooth, and AH 26 sealer was sucked into the root canal system. Radiographs of the root-filled teeth were analysed and the length of the root filling, the presence of voids and the area of any other fillings determined. RESULTS: The root canal fillings of the control group (0.1 +/- 0.1 mm) and those of the NIT/gutta-percha group (0.3 +/- 0.1 mm) were both overextended when taking the apical constriction as a reference point. Root canal fillings of the NIT/gutta-percha group were statistically (P < 0.05) significantly longer than those of the NIT without gutta-percha group. The latter showed slightly underextended root canal fillings (-0.14 +/- 0.1 mm). CONCLUSIONS: The present investigation demonstrated the performance of the NIT-obturation method in vivo. Root canals filled by the reduced-pressure-method using sealer combined with gutta-percha cones exhibited equivalent radiographic quality compared to conventionally filled canals.     

Ultrasonic condensation of gutta-percha: the effect of power setting and activation time on temperature rise at the root surface - an in vitro study

AIM: To determine the effect of power setting and duration of activation on the temperature rise at the root surface during root canal obturation by ultrasonic condensation of gutta-percha. METHODOLOGY: A human maxillary canine was used in an in vitro split tooth model to allow repeated obturation of the root canal system using an ultrasonic device to thermocompact gutta-percha. Combinations of power settings (1, 3 and 5) and durations of activation (4, 10 and 15 s) were used to test their effect on temperature rise at the root surface using eight K-type thermocouples at the mid-root and apical levels. At the end of each obturation, the tooth was disassembled to remove the gutta-percha in preparation for the next obturation (n = 10 for each combination). Multiple linear regression models were used to investigate the effects of power setting, duration of activation and thermocouple location on the maximum temperature rise recorded. RESULTS: Only one combination of power setting (5) and duration of activation (15 s) resulted in temperature rise in excess of 10 degrees C. The maximum temperature rise at the mid-root level was significantly (P < 0.001) greater than that recorded apically. It is also significantly affected by the combination of power setting and duration of activation. CONCLUSIONS: Temperature rises at the root surface during ultrasonic condensation of gutta-percha in excess of 10 degrees C were evident in only one combination of power (5) and time (15 s) settings at the mid-root level.     

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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。     

Comparison of a warm gutta-percha obturation technique and lateral condensation.

This study was designed to compare a warm gutta-percha obturation technique, Thermafil Plus (Tulsa Dental, Tulsa OK), with lateral condensation for the ability to adapt gutta-percha to the walls of a root canal system. An extracted sectioned and mounted maxillary central incisor had canal irregularities created and was subsequently subjected to multiple obturations using both techniques. Length of fill, replication to working length, number of artificial depressions replicated, quality of replications, number of voids, and general appearance of obturation were all evaluated using standardized criteria. Data evaluation consisted of a one way analysis of variance on the same type defects between obturation groups followed by a Scheffé post-hoc test. A statistically significant difference was found between the groups in each category of evaluation. Gutta-percha using Thermafil was better able to flow into lateral spaces, had fewer voids, and replicated the surface of the root better. It also, however, was extruded out the apical foramen more than in the lateral condensation group.     

应用micro-CT评价不同封闭技术的根管充填质量

目的: 利用micro-CT评价不同封闭技术对根管充填质量的影响。方法: 选取单根管上颌前牙40颗,截冠后,使牙根长度为12 mm。利用ProTaper预备至F3,将处理好的样本随机分为4组（n=10）,用牙胶尖和（或）iRoot SP分别使用冷侧压法、热牙胶法、单尖法、纯糊剂法完成充填。1周后,应用micro-CT扫描并测量分析根管内存在的间隙,计算各组存在气泡的横截面比例和充填材料整体、冠1/3、中1/3、尖1/3的体积比,采用SPSS 20.0软件包对数据进行统计学分析。结果: 热牙胶组存在气泡的横截面比例最少(P<0.05);整体、冠1/3、中1/3热牙胶组的充填材料体积比最大(P<0.05),而尖1/3纯糊剂组的充填材料体积比最大（P<0.05）,其他各组间均无显著差异。结论: 所有封闭技术均不能避免气泡产生,热牙胶法充填质量最高。     

Comparison of the obturation of lateral canals by six techniques.

The following obturation techniques were compared on their ability to obturate lateral canals in vitro, lateral condensation (LC), continuous wave of condensation (CW), warm vertical condensation (WV), carrier-based thermoplasticized gutta-percha (CB), warm lateral condensation (WL), and vertically condensed high-temperature gutta-percha (HT). A root canal system with lateral canals in the coronal, middle, and apical thirds was prepared in resin blocks. Each block was obturated using each technique (n = 30, 15 each, with and without sealer). The length of gutta-percha and sealer in each of the lateral canals was measured with a measuring microscope and statistically compared. All techniques obturated all three levels of lateral canals with sealer. WV, CB, and CW were able to fill the lateral canals with gutta-percha significantly better when root canal sealer was used. WV, CB, CW, and HT filled the coronal and middle lateral canals significantly better with gutta-percha than LC or WL condensation. CB and CW filled the apical lateral canal significantly better with gutta-percha than HT, WV, WL, or LC.     

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.     

An assessment of the plastic Thermafil obturation technique

Adaptation and placement of alpha-phase gutta-percha delivered with a plastic core-carrier, Thermafil, was compared to the lateral condensation of gutta-percha in a specific tooth model. Fifty-one mandibular molar roots with separate canals, patent canal orifices and curvatures greater than 15 degrees were cleaned and shaped with K-files and 2.5% sodium hypochlorite to a size 30 at the apex, and flared with Hedstrom flies to create a continuously tapering funnel preparation. Canals were randomly obturated with Sealapex root canal sealer and either alpha-phase gutta-percha on a plastic Thermafil carrier, or standard beta-phase gutta-percha with lateral condensation. Roots were radiographed from the proximal and evaluated by three examiners, based on established criteria for overall material adaptation, apical adaptation, and filling material extrusion. Thermafil provided a statistically significant better over-alt canal obturation (P < 0.001), while, in the apical third, both techniques were not significantly different (P > 0.05). When the apical orifice was patent there was a significant propensity for the extrusion of filling materials beyond the apex (P < 0.001) with the Thermafil technique.     

Comparative study of two canal obturation techniques by image analysis and EDS microanalysis

AIM: The aim of this in vitro study was to compare the marginal adaptation achieved by two obturation techniques (lateral condensation and Thermafil) using human teeth prepared by continuous rotation with the HERO 642(R) system. METHOD: The percentages of gaps and sealer on the root canal surface were determined by analysing the images of 12 sections per tooth. Tubule sealer penetration was assessed by backscattered scanning electron microscopy and energy dispersive spectrometry microanalysis. RESULTS: The Thermafil obturation technique resulted in virtually no gaps and very low amounts of sealer on the root surface, unlike the lateral condensation technique. Tubule sealer penetration occurred with both techniques, but was deeper, especially in the mid and apical zones, with the lateral condensation technique.     

Qualitative evaluation of two endodontic obturation techniques: tapered single-cone method versus warm vertical condensation and injection system: an in vitro study

Forty two single-rooted teeth, prepared with the Mtwo system, were divided into three groups based on the filling method: control, "Single-cone" (n = 20) (Mtwo gutta-percha single-cone tapered according to the diameter, length and conicity of the preparation) and "Combined system" (n = 20) (BeeFill 2in1). The parameters studied were apical leakage, gutta-percha adjustment, number of voids, presence/absence of sealer, root canal morphology, residual fragments, and filling of lateral/accessory canals. A dye penetration test was carried out (methylene blue). The teeth were embedded in resin, cut transversally and observed. The data were analyzed with non-parametric Mann-Whitney and Spearman tests. Comparative tests between the two groups showed that the "Combined system" was superior in terms of apical leakage (P < 0.01), gutta-percha adjustment (P < 0.05) and filling of lateral/accessory canals (P < 0.05). There were statistically significant correlations between master cone adjustment and root canal morphology (P < 0.01) in the "Single-cone" group. In the "Combined system" group, a relation was observed between the voids and root canal morphology (P < 0.05) and between voids and residual fragments (P < 0.05). The quality of obturation with warm gutta-percha was better than that of the tapered single-cone technique. Root canal morphology influences gutta-percha adjustment. Residual fragments on the root canal reduce sealing ability.     

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.     

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.     

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.     

Obturation quality utilizing ultrasonic cleaning and sealer placement followed by lateral condensation with gutta-percha

The quality of canal obturation utilizing ultrasonic or hand instrument sealer placement followed by lateral condensation with gutta-percha was investigated. This in vitro study using the mesial roots of human mandibular molars showed the ultrasonic method of sealer placement resulted in a more thorough coverage of canal walls than when the sealer was placed with hand instruments. The difference was statistically significant (p less than 0.005). Ultrasonic sealer placement may be safely and effectively utilized when obturating a complex root canal system.     

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.     

In vivo findings associated with heat generation during thermomechanical compactionof gutta-percha. Part II. Histological response to temperature elevation on the external surface of the root

An in vivo investigation is described and a histological evaluation made of the effect of canal obturation by thermomechanical compaction of gutta-percha and sealer on the cementum on the lateral surface of the root and adjacent periodontal membrane and alveolar bone of the ferret canine after time intervals of 24 hours, 20 days and 40 days. These tissue reactions were compared with those in the roots of control teeth filled by lateral condensation of cold gutta-percha and sealer. Iatrogenic damage was apparent in a minority of the experimental specimens 20 and 40 days after obturation.     

Quality of Obturation Achieved by a Non–gutta-percha–based Root Filling System in Single-rooted Canals

Introduction

The present study examined the quality of obturation in root canals filled by an experimental non–gutta-percha–based (NGP) root filling system using warm vertical or cold lateral compaction. The quality of obturation was evaluated by comparing the volumetric percentage of gaps and voids identified from similar canals obturated with gutta-percha and an epoxy resin–based sealer using the same obturation techniques.

Methods

Forty single-rooted premolars with oval-shaped canals were cleaned, shaped, and obturated with 1 of the 4 material/obturation technique combinations (n = 10). Filled canals were scanned with micro–computed tomographic imaging. Reconstructed images were analyzed for the volumetric percentage of gaps and voids at 3 canal levels (0–4, 4–8, and 8–12 mm from the working length). Roots were sectioned at the 4-mm, 8-mm, and 12-mm levels. Scanning electron microscopic images of negative replicas of root sections were examined to quantify the circumferential percentage of interfacial gaps and the area percentage of intracanal voids. Data were analyzed with parametric or nonparametric statistical methods.

Results

A statistically significant difference was found for the volumetric percentage distribution of gaps and voids for “obturation technique” but not for “material.” Significantly higher percentages of gaps and voids were identified in canals obturated with the NGP system using cold lateral compaction. Examination of negative replicas ascribed this difference to a higher area percentage of interfacial gaps rather than more intracanal voids.

Conclusions

Using warm vertical compaction, the NGP system fulfils the objective of 3-dimensional obturation of the canal space in a manner comparable with the results achieved with gutta-percha and a root canal sealer.