In vitro evaluation of apical leakage of root canal fillings after in situ obturation with thermoplasticized and laterally condensed gutta-percha

The purpose of this investigation was to compare In vitro the sealing ability of root canal treatments performed In situ with injected thermoplasticized gutta- percha compared with the lateral condensation technique. Thirty single-rooted teeth with straight canals, due for extraction For orthodontic or periodontal reasons were prepared using a step-back technique. Teeth were then divided randomly into groups A and B and obturated, respectively, with the sectional injection thermoplasticized gutta-percha and the lateral condensation techniques. Teeth were extracted after 15 days, immersed in India ink for 3 days and the leakage was determined using area-metric analysis. The roots were ground transversally and the root portion was incrementaly removed with successive steps of 250 μm each, up to the coronal level of the dye penetration. Every section was photographed with a stereoscopic microscope under the same magnification (×20); 310 photographs were taken. Measurements of the area covered by ink as well as the whole cross-sectional area of the canal were made from each photograph with the aid of a digitizing computer. The measurements were subjected to non-parametric statistical analysis. No significant difference was found (P>0.05). The technique of lateral condensation proved to be better in the first five sections (1.2 mm from the foramen) while thermoplasticized gutta-percha technique was superior in the rest of the root canal.     

A comparative study of apical leakage of Apexit, Ketac-Endo, and Diaket root canal sealers

The purpose of this study was to compare the apical leakage of Ketac-Endo, Apexit, and Diaket. Fifty freshly extracted human maxillary anterior teeth were used. The anatomical crowns were removed at the amelocemental junction, and step-back preparation of the roots canals was performed with K-type files to size 40 using 2 ml of 5.25% NaOCl irrigant after each file change. The roots were randomly divided into five groups of 10 roots each: three experimental and two control groups. The experimental groups were as follows: group 1, Apexit; group 2, Ketac-Endo; and group 3, Diaket. Root canals were filled with one of the sealers and gutta-percha using lateral condensation. After the specimens were stored in 100% humidity at 37 degrees C for 2 wk, the roots were covered with two layers of nail polish and immersed in 2% methylene blue for 7 days. Each tooth was split into two sections, and dye penetration was evaluated independently by three examiners using a stereomicroscope at x20 magnification. Mann-Whitney U analysis showed that there was no significant difference between Apexit and Diaket (p > 0.05). However, there was significantly more leakage with Ketac-Endo (p < 0.05).     

A comparative study of contact angles of four different root canal sealers

The present in vitro study was conducted with the aim of evaluating and comparing the contact angles of three different types of root canal sealers--Roth 801, AH26, and RSA RoekoSeal--with the contact angle of a newly developed silicone-based root canal filling material (Gutta-Flow) on dentin and gutta-percha surfaces at two different time periods. The contact angles were determined mathematically by measuring software and were calculated from base width and height of the droplet meniscus of each sealer. Under the conditions of this study, Roth 801 and AH26 recorded lower values of contact angles when root dentin surface was used as the substrate. RSA RoekoSeal and Gutta-Flow seem to spread similarly on dentin and gutta-percha surfaces, although the contact angles of these silicone-based sealers were found to be significantly higher than the contact angles of Roth 801 and AH26 sealers. According to these findings, it can be concluded that conventional root canal sealers (Roth 801 and AH26) may passively have the potential for better wettability of dentin and gutta-percha surfaces than that of silicone-based sealers (RSA RoekoSeal and Gutta-Flow). This fact means that Roth 801 and AH26 may have a better spreading capacity under clinical conditions on the root canal walls and gutta-percha surfaces. Application of a sufficient load during lateral or vertical compaction seems to be needed for RSA RoekoSeal and Gutta-Flow to satisfactorily wet gutta-percha and dentin under clinical conditions.     

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.     

A 1-year follow-up study on leakage of four root canal sealers at different thicknesses

Determination of leakage using a fluid transport model allows measurement of leakage in a longitudinal manner. Leakage of four sealers at three different thick- nesses in 225 bovine root sections, after storage in water for 1 year, was measured again using the same method- ology. The change in seal over time for each sealer was observed. The results after the second measurement showed that every sealer produced the best seal when the sealer layer was the thinnest. AH26, Ketac-Endo and Tubli-Seal showed a reduction in leakage over time and gave significantly less leakage than Sealapex (P<0.005). Sealapex showed sigdicantly more leakage after storing in water for 1 year (P<0.005). Therefore, the long-lasting seal of sealer may, among other influencing factors, depend on the layer thickness and the solubility of the material.     

根管封闭剂细胞毒性的比较研究

目的:比较5种根管封闭剂根管充填后不同时期对L929小鼠成纤维细胞的细胞毒性.方法:选取18个单根前磨牙,截冠,拔髓,定长,根管预备,冲洗后,随机分组,分别用5种不同根管封闭剂(Roeko-seal,AH-plus,CRCS,Vitapex,Apexit)结合1根牙胶尖进行根管充填,冠方用玻璃离子封闭.设只用1根牙胶尖组作为对照.采用MTT比色试验,分别检测各组根管封闭剂根管充填24 h、1周和5周后洗脱液的细胞毒性.结果:充填后24 h,Roeko seal组无细胞毒性,其余4组都有一定的细胞毒性,其中CRCS组细胞毒性最大,与剩余4组封闭剂有显著的统计学差异(P＜0.01);充填后1周,Roeko seal组无细胞毒性,其余4组都有一定的细胞毒性,其中Vitapex组毒性最大,Apexit组次之,两组均与剩余两组有显著的差异(P＜0.01);充填后5周,Roeko seal组无细胞毒性,Vimpex组也基本无细胞毒性,其余3组都有一定的细胞毒性,与前两组相比有显著的差异(P＜0.01).结论:①Roeko seal无细胞毒性,是一种生物相容性良好的根管封闭剂.②AH-plus、CRCS、Apexlt有一定的细胞毒性,随着时间的推移,其细胞毒性呈现递减的趋势.③Vitapex在初始阶段具有一定的细胞毒性,其大小随时问而递减,在充填后5周时已基本无细胞毒性.     

Polymicrobial leakage of four root canal sealers at two different thicknesses

The present study investigated the sealing ability of four root canal sealers at two different thicknesses. There were 82 maxillary incisors roots prepared with Gates Glidden drills up to size 6 and divided into four groups: Pulp Canal Sealer, EndoREZ, Sealapex, and AH Plus. Each group was divided in two subgroups and gutta-percha cylinders 1.5 or 1 mm wide were used, respectively. The roots were mounted in a bacterial leakage model and the system was checked daily during the following 12 wk. Data were analyzed by Log-Rank test and Student t-test. In the thin layer samples, the sealers demonstrated similar results while, in the thick layer samples, AH Plus revealed the best performance. Generally, greater sealer thickness influenced negatively the sealing ability of the root canal filling, except in AH Plus samples.     

The removal of gutta-percha and root canal sealers from root canals

The removal of gutta-percha from root-filled teeth is required for re-treatment of failed endodontic treatment and to prepare a space for placement of a post. Complete removal of filling material and sealer is a requirement for success. A review was undertaken of the current literature on methods of gutta-percha and sealer removal. Clinical recommendations based on current evidence are included. A combination of methods may be required to remove filling materials effectively.     

Comparison of laterally condensed and low-temperature thermoplasticized gutta-percha root fillings

The aim of this study was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or low-temperature thermoplasticized gutta-percha (Ultrafil). One hundred freshly extracted human, mature single-rooted teeth were divided into four identical groups of 25 teeth on the basis of root canal shape. The root canals of two groups were prepared in such a way to produce a relatively parallel shape with little or no flare toward the coronal orifice. The root canals of the other two groups were prepared in such a way as to produce a canal shape that was deliberately more flared to ensure that they were wider at the orifice than at the end point of the preparation. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one flared group and one parallel group were obturated using cold lateral condensation, and the canals of the other two groups were obturated using low-temperature thermoplasticized gutta-percha. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a 4-point scale. Canals filled with thermoplasticized gutta-percha had significantly less apical dye penetration than those obturated by lateral condensation (p < 0.001). Lateral condensation achieved significantly better scores for radiographic quality than thermoplasticized gutta-percha from both the buccolingual (p < 0.005) and mesiodistal views (p < 0.001). Low-temperature thermoplasticized gutta-percha root fillings were associated with significantly more apical extrusion of sealer (p < 0.001) and gutta-percha (p < 0.005). Under laboratory conditions the low-temperature thermoplasticized gutta-percha had better sealability but poorer radiographic quality than lateral condensation.     

单尖法和热牙胶法根管充填根尖封闭性能的比较研究

目的 比较3种封闭剂AH-Plus, iRoot SP和GuttaFlow2分别配合单尖法充填和热牙胶充填的根尖封闭性能。方法 选取近期拔除的70颗单根管前磨牙,截冠后采用Waveone gold系统预备至P#,随机分为6个实验组(每组10颗)和2个对照组(每组5颗)。分别行单尖法充填和热牙胶充填,即AH-Plus单尖法组(A1组),AH-Plus热牙胶组(A2组),iRoot SP单尖法组(B1组),iRoot SP热牙胶组(B2组),GuttaFlow2单尖法组(C1组),GuttaFlow2热牙胶组(C2组),阳性对照组(D组)和阴性对照组(E组)。将充填完成的牙齿进行染料渗透实验后,通过纵切片法检测根尖的微渗漏情况。结果 A1组微渗漏值最大,B2组微渗漏值最小,同种封闭剂下单尖法充填和热牙胶充填根尖封闭性差异无统计学意义(P>0.05),同种充填技术下3种封闭剂的封闭性差异无统计学意义(P>0.05)。结论 3种根管封闭剂均不能完全封闭根管,单尖法充填和热牙胶充填在根尖封闭效果上无显著差异。     

Adhesion of root canal sealers to bovine dentine and gutta-percha

The adhesive properties of eight root canal sealers, applied as a thin layer between a dentine and a gutta-percha surface, were investigated. Tensile bond strengths ranged from 0.02 MPa (Sealpex) to 2.38 MPa (AH26). Inspection of fractured surfaces indicated failure of adhesion to dentine (Tubli-Seal) and to gutta-percha (AH26, Diaket) as well as failure of cohesion (CRCS, Kloroperka N-O, ProcoSol, rosin chloroform, Sealapex). Pretreatment of the dentine surface with EDTA caused a significant increase in bond strength for ProcoSol, rosin chloroform, Sealapex, and Tubli-Seal.     

A quantitative evaluation of apical leakage of four root-canal sealers

AIM: This in vitro study evaluated the microleakage of root fillings involving four root-canal sealers including AH Plus (De-Trey, Switzerland), RoekoSeal (Roeko, Germany). Ketac-Endo (ESPE, (Germany) and Sultan (Sultan Chemists, USA. METHODOLOGY: Forty extracted human maxillary anterior teeth were used. The coronal part of each tooth was removed and the root canals were prepared using the step-back technique and apical enlargement to size 60 file. The specimens were randomly divided into four groups of 10 samples, filled with one of the test materials and gutta-percha cones by the cold lateral condensation technique. A fluid filtration method was used for quantitative evaluation of apical leakage. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section. Measurements of fluid movement were made at 2-min intervals for 8 min. Water transport through existing voids in the obturated canals could be measured reproducibly in this way. The quality of the seal of each specimen was measured after 7,14 and 21 days. RESULTS: Statistical analysis indicated that all the root fillings showed less leakage after 21 days (P < 0.05). Fillings incorporating Sultan showed significantly more leakage than all other sealers. CONCLUSIONS: Root fillings with RoekoSeal in combination with cold lateral condensation technique showed better sealing than those with Ketac-Endo, AH Plus and Sultan sealers after 21 days. The fluid filtration test used in this study gave quantitative results and allowed nondestructive long-term evaluation of specimens.     

Influence of irrigants on the coronal microleakage of laterally condensed gutta-percha root fillings

AIM: To assess in vitro coronal microleakage in extracted human teeth after root-canal treatment, using different endodontic irrigants. METHODOLOGY: Fifty teeth with single root canals were prepared and filled using the lateral condensation of gutta-percha and Endométhasone sealer. Canal preparation consisted of initial shaping of the coronal two-thirds with Gates-Glidden burs size 2 and 3, followed by preparation of the apical stop and step-back flaring with manual files. Each group (n = 10) was irrigated with the following solutions: I--1% NaOCl, II--1% NaOCl + 17% EDTA, III--2% chlorhexidine gel, IV--2% chlorhexidine gel + 1% NaOCl, and V--distilled water. After root-canal filling, the teeth were incubated at 37 degrees C for 10 days followed by 10 days immersion in human saliva and an additional 10 days in India ink. The teeth were cleared and maximum dye penetration was determined digitally in millimetres. Statistical analysis was carried out using the Kruskal-Wallis test. RESULTS: Least leakage occurred with 1% NaOCl + 17% EDTA (2.62 mm) and 2% chlorhexidine gel (2.78 mm) (P > 0.05). NaOCl (3.51 mm), distilled water (6.10 mm) and 2% chlorhexidine gel + 1% NaOCl (9.36 mm) gave increased leakage with a significant difference compared to NaOCl + 17% EDTA and 2% chlorhexidine gel, and compared to one another (P < 0.05). CONCLUSIONS: Under the condition of this study, irrigation method during root-canal treatment influenced coronal microleakage. NaOCl + EDTA and chlorhexidine gel allowed better sealing following root filling.     

Life and AH26 as sealers in thermatically compacted gutta-percha root canal fillings: leakage to a dye

Calcium hydroxide-containing root canal sealers may encourage apical obturation by cementum. Hard-setting bases with calcium hydroxide induce calcification, but set too quickly to permit lateral condensation of gutta-percha. Since thermatic compaction requires less time than lateral condensation, the possibility of using this method with Life as a sealer was investigated. Seventy roots were prepared and filled with gutta-percha using the Engine Plugger for thermatic compaction. In one group of 20 Life was used as a sealer. AH26 was used in another group of 20. The remainder served as controls. Leakage was tested by linear penetration of Procion B Blue dye measured after clearing the teeth. In the Life group the mean dye penetration was 0.575 mm versus 1.025 mm in AH26, but the difference was not statistically significant. The results indicated that Life could be used in thermatic compaction of gutta-percha and that it provided a seal comparable to that obtained with AH26.