Evaluation of apical sealing of three endodontic sealers

AIM: The apical sealing ability of three different endodontic sealers was evaluated in extracted teeth using dye penetration. METHODOLOGY: The root canals of 99 extracted human maxillary central incisors were prepared sequentially 2 mm beyond the apical foramen with a size 55 Nitiflex file. The teeth were divided into three experimental groups and obturated by lateral condensation of cold gutta-percha and one of the following sealers: group 1, zinc oxide and eugenol sealer (Fill Canal); group 2, glass ionomer sealer (Ketac-Endo) and group 3, epoxy resin sealer (AH Plus). The teeth were covered with nail varnish to within 1 mm of the apical foramen and immersed in 2% methylene blue in a reduced pressure environment for 24 h. After this period, the teeth were washed and cut longitudinally for apical leakage analysis. The values were obtained from the maximum depth of leakage as well as the average between the maximum and minimum values observed for each group. RESULTS: Statistical evaluation of the results showed no significant difference in the leakage between Fill Canal and Ketac-Endo (P > 0.05). Leakage with AH Plus was significantly less (P < 0.01) than with the other sealers. CONCLUSIONS: All three sealers allowed some leakage to occur. Leakage with AH Plus was significantly different than with Fill Canal or Ketac-Endo.     

In vivo sealing ability of calcium hydroxide-containing root canal sealers

Abstract It was the purpose of this study to determine the sealing ability of 2 commercially available calcium hydroxide-containing root canal sealers, CRCS and Sealapex. One hundred sixty single-rooted human teeth were used. The clinical crowns were removed and the roots were cleaned mechanically and by immersion for 24 h in 5% sodium hypochlorite. The root canals were then instrumented to size 80 at the apical foramen and the roots were sterilized by γ-radiation. Under aseptic conditions the root canals were filled with a gutta-percha master cone size 70 and Sealapex (48 roots), CRCS (48 roots), and a zinc oxide-eugenol type sealer, Roth 801 (50 roots). The coronal aspects of the root canals were then sealed with zinc oxide-eugenol cement. In order to bring the roots and root filling materials in contact with tissue and tissue fluids, the roots were implanted subcutaneously in rabbits for 90 days and 1 year. Leakage as demonstrated by penetration of India ink was evaluated using a stereomicroscope. The best results were obtained with CRCS. Significantly less leakage occurred with both calcium hydroxide-containing sealers than with the traditional zinc oxide-eugenol sealer.     

Histological evaluation of the response of apical tissues to glass ionomer and zinc oxide-eugenol based sealers in dog teeth after root canal treatment

Abstract— The object of the study was to compare two commercial root canal sealers: Ketac-Endo (a glass ionomer cement) and Fill Canal (a zinc oxide-eugenol cement). A total of 34 root canals from dog premolars with vital pulps were used. After instrumentation, the root canals were sealed with Ketac-Endo and Fill Canal cements using gutta-percha and a lateral condensation technique. After 270 days the animals were sacrificed with an anesthetic overdose and the maxillae and mandibles were removed and fixed in formalin for 48 h. After routine histological processing the sections were stained with hematoxylin-eosin and Mallory trichrome stains. Microscopic analysis revealed that Ketac-Endo cement presented better results than Fill Canal cement.     

碘仿氢氧化钙糊剂注射根管充填的微渗漏实验研究

目的 :了解碘仿氢氧化钙糊剂 (iodoform -calciumhydroxideICH)注射根管充填对根尖孔的封闭性能。方法 :5 0颗离体单根牙随机分为实验组和对照组。两组分别用注射型ICH和氧化锌丁香油糊剂组单尖充填根管 ,采取染料渗入法检查根尖孔微渗漏 ,在解剖显微镜下测量染料渗入距离。结果 :ICH组微渗漏值平均 0 .60 2mm ,氧化锌丁香油糊剂组微渗漏值平均 1.2 3 6mm ,经t检验 ,P <0 .0 5 ,两组渗漏值具有显著性差异。结论 :注射型碘仿氢氧化钙糊剂对根尖孔的封闭性优于氧化锌丁香油糊剂     

碘仿氢氧化钙糊剂充填感染根管的微漏实验研究

目的：探讨碘仿氢氧化钙（ICH）糊剂充填感染根管后对根尖孔的封闭性能。方法：将49个牙周牙髓联合病变需要拔除的患牙随机分为4组：A组和A1组用ICH糊剂充填根管；B组、B1组用氧化锌丁香油糊剂加牙胶尖充填根管。A组、B组充填后即刻拔牙。A1组、B1组充填后3又拔牙。采用染料渗入法检查根尖孔微漏值，在解剖显微镜下测量染料渗入距离。结果：A组、B组微漏值分别为1．08和1．18mm，对根尖孔的封闭性能二者相比无显著差异（P＞0．05）。A1组微漏值由1．08mm上升为3．05mm。B1组的微漏值为1．58mm，对根尖孔仍有良好的封闭性。A1组较B1组封闭性能差，两者有显著差异。结论：ICH糊剂充填感染根管一段时间后对根尖孔的封闭性能不佳，只能作为暂时根充材料。     

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.     

Bacterial coronal leakage after obturation with three root canal sealers

The purpose of this study was to compare the bacterial leakage of root canals obturated with three root canal sealers, using Endodontalis faecalis as a microbial tracer to determine the length of time for bacteria to penetrate through the obturated root canal to the root apex. Seventy-five, single-rooted teeth with straight root canals had the crown cut off at the cementoenamel junction. Root canals were instrumented by a step-back technique. The prepared teeth were randomly divided into 3 groups of 19 teeth each and another 2 groups as positive and negative controls (9 teeth each). The experimental groups were dependent on the sealer used: AH-Plus, Apexit, and Ketac-Endo. The root canals were obturated using a lateral condensation technique. After 24 h the teeth were attached to microcentrifuge tubes with 2 mm of the root apex submerged in Brain Heart Infusion broth in glass test tubes. The coronal portions of the root canal filling materials were placed in contact with E. faecalis. The teeth were observed for bacterial leakage daily for 30 and 60 days. With the chi2 test for comparing pairs of groups at the 0.05 level (p < 0.05), there was no statistical difference between Ketac-Endo and AH-Plus (p > 0.06), but Apexit had significantly higher leakage (p < 0.05) at 30 days. After 60 days there was no statistical difference between Ketac-Endo and Apexit (p > 0.05), but Apexit leaked more than AH-Plus. The conclusion drawn from this experiment was that epoxy resin root canal sealer was found to be more adaptable to the root canal wall and filling material than a calcium hydroxide sealer when bacterial coronal leakage was studied.     

Tissue response to an epoxy resin-based root canal sealer

Abstract— Thc objective of the present study was to evaluate two different types of root canal sealers: AH Plus (an epoxy resin-based sealer) and Fill Canal (a zinc oxide-eugenol based sealer). A total of 34 root canals with vital pulp from dogs' premolars were used. After instrumentation, the root canals were filled with gutta-percha and AH Plus or gutta-percha and Fill Canal sealers using a classical technique of lateral condensation. After histological processing, the sections were stained with hematosylincosin or Mallory's trichrome stain. Inflammatory cells or areas of necrosis were not associated with AH Plus. Hard tissue formation apically to the material was observed in 14 specimens. The Fill Canal sealer presented an inflammatory response of moderate intensity in the periapical region, mainly adjacent to the material.     

The effect of tubular penetration of root canal sealers on dye microleakage

An in vitro study of a possible correlation between penetration of dentinal tubules by four root canal sealers and microleakage of external fluids into the canal was done using a dye leakage method and scanning electron microscopy. The root canals of 45 teeth were instrumented and the smear layer removed prior to obturation of root canals with gutta-percha and one of four sealers: Diaket, Endomethasone, CRCS or Ketac-Endo. The extent of leakage was scored after immersion in India ink for 72 h. The same specimens were also used for scanning electron microscopic evaluation. There was a statistical difference in leakage patterns between the groups ( P <0.05). Diaket had lower microleakage scores than the other sealers ( P <0.05). When the scores for penetration of sealers into the tubules were analysed, Ketac-Endo demonstrated the least penetration ( P <0.01). There appeared to be a converse relation between tubular penetration and dye leakage, but the correlation was not statistically significant ( P <0.05).     

In vivo sealing ability of calcium hydroxide-containing root canal sealers

It was the purpose of this study to determine the sealing ability of 2 commercially available calcium hydroxide-containing root canal sealers, CRCS and Sealapex. One hundred sixty single-rooted human teeth were used. The clinical crowns were removed and the roots were cleaned mechanically and by immersion for 24 h in 5% sodium hypochlorite. The root canals were then instrumented to size 80 at the apical foramen and the roots were sterilized by gamma-radiation. Under aseptic conditions the root canals were filled with a gutta-percha master cone size 70 and Sealapex (48 roots), CRCS (48 roots), and a zinc oxide-eugenol type sealer, Roth 801 (50 roots). The coronal aspects of the root canals were then sealed with zinc oxide-eugenol cement. In order to bring the roots and root filling materials in contact with tissue and tissue fluids, the roots were implanted subcutaneously in rabbits for 90 days and 1 year. Leakage as demonstrated by penetration of India ink was evaluated using a stereomicroscope. The best results were obtained with CRCS. Significantly less leakage occurred with both calcium hydroxide-containing sealers than with the traditional zinc oxide-eugenol sealer.     

A comparison of root fracture resistance using two root canal sealers

AIM: The aim of this study was to compare in vitro root fracture resistance following root canal filling with either Ketac-Endo or Roth's root canal sealer. METHODOLOGY: The roots of 40 teeth with single canals were instrumented and placed randomly into four groups of 10 teeth. The prepared canals were obturated with lateral compaction using gutta-percha and Roth's 801 sealer, lateral compaction and Ketac-Endo sealer or with a single cone and Ketac-Endo sealer; the fourth group acted as unfilled controls. The roots were stored for 2 weeks in 100% humidity prior to being mounted in acrylic resin blocks. A steel tipped rod attached to an Instron testing machine was positioned against the canal opening and a slowly increasing force was applied until root fracture occurred. The results were subjected to statistical analysis using Kruskal-Wallis one-way ANOVA. RESULTS: There were no significant differences between the groups in terms of force required to vertically fracture the roots. CONCLUSIONS: Under the conditions of this study, the use of Ketac-Endo sealer in conjunction with lateral compaction or single-cone obturation techniques does not increase the fracture resistance of root-filled teeth.     

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.     

Sealing ability of potential retrograde root filling materials

Abstract The sealing ability of two potential retrograde root filling materials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol) was compared with that of amalgam using three methods of assessment: bacterial leakage, confocal microscopy and Indian ink leakage. The root canals of 80 extracted human single-rooted teeth were prepared. All the teeth were apicected, retrograde cavities were prepared and then divided into four equal groups of 20 teeth. The teeth were sterilised by autoclaving and the retrograde cavities filled with the test materials. In the control group, retrograde cavities in 10 teeth were left unfilled while cavities in another 10 teeth were sealed with cyanoacrylate cement. The teeth were first subjected to a bacterial leakage test using Enteroccocus faecalis as a leakage marker. After which, the adaptation of the retrograde root fillings was assessed using a confocal optical microscope. Finally, the teeth were processed for the Indian ink leakage test. Bacterial leakage occurred in more teeth filled with amalgam compared with both Vitrebond and Kalzinol (P < 0.001), between which there were no differences. With confocal microscopy, the size of the marginal gap was largest with amalgam and smallest with Vitrebond; all differences were statistically significant (P < 0.001). Finally, there was more Indian ink penetration with amalgam compared with both Vitrebond and Kalzinol (P < 0.001) but there were no differences between Vitrebond and Kalzinol. Although there were individual differences within samples, overall, the three methods of assessment produced similar results. The sealing ability of Vitrebond and Kalzinol was similar and both materials were better than amalgam.     

Sealing ability of thermoplasticized gutta-percha in root canal obturation using a sectional vs. a single-phase technique

Abstract Properly prepared straight root canals of freshly extracted maxillary canines and central incisors were used to evaluate the sealing ability of the sectional thermoplasticized gutta-percha obturation technique, with or without sealer and the single-phase thermoplasticized gutta-percha filling technique. The teeth were divided into 3 groups (A, B, C) of 20 teeth and were obturated using the 3 thermoplasticized gutta-percha techniques. Group A: single phase with sealer; group B: sectional technique without sealer; and group C: sectional technique with sealer. The obturated teeth were immersed in India ink for 3 days followed by clearing procedures. The teeth were then examined under a stereo microscope and the linear leakage was recorded. Statistical unpaired Student's t-tests showed significantly less dye penetration in teeth obturated using the sectional technique with sealer (group C) than in teeth obturated with the single-phase technique with sealer (group A) or the sectional technique without sealer (group B).     

Cortisomol糊剂用于感染根管充填的临床疗效

目的:对Cortisomol糊剂用于感染根管充填的临床疗效进行评价。方法:选择18～60岁慢性牙髓炎、慢性根尖周炎病人151例共160个患牙,常规根管预备后,随机分为实验组和对照组各80个患牙。实验组采用Cortisomol糊剂加牙胶尖充填根管,对照组采用碘仿氧化锌丁香油糊剂加牙胶尖充填,观察根充后3 d、1周后反应,并观察术后1年的临床疗效。结果:术后3 d、1周,实验组术后反应发生率低于对照组,差异有统计学意义(P<0.05);术后1年,两组临床疗效无显著性差异(P>0.05)。结论:Cortisomol根充糊剂可明显减少根管后反应,有较好的临床疗效。     

Evaluation of the Trifecta obturating technique

Abstract – 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 the Trifecta obturating system. 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 as to produce a relatively parallel canal shape with little or no flare towards 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 endpoint 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 and one parallel group were obturated using cold lateral condensation and the canals of the other two groups were obturated using the Trifecta system. 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 thermoplasticised 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 thermoplasticised gutta‐percha from both the bucco‐lingual (P<0.001) and the mesio‐distal views (P<0.001). Root canals obturated using the Trifecta technique showed significantly more apical extrusion of sealer than those obturated by lateral condensation (P<0.001). Under laboratory conditions the Trifecta technique had better sealability but poorer radiographic quality than lateral condensation.     

Push‐out bond strength of gutta‐percha with a new bioceramic sealer in the presence or absence of smear layer

The purpose of this study was to compare the bond strength of a new bioceramic sealer (EndoSequence BC Sealer) and AH Plus in the presence or absence of smear layer. Extracted single‐rooted human teeth were prepared and randomly divided into four groups. In groups 1 and 3, the root canals were finally irrigated with 5.25% NaOCl and smear layer was not removed, but in groups 2 and 4, the root canals were finally irrigated with 17% EDTA followed by 5.25% NaOCl in order to remove the smear layer. In groups 1 and 2, the root canals were obturated with gutta‐percha/AH Plus, but in groups 3 and 4, obturation was performed with gutta‐percha/EndoSequence BC Sealer. Push‐out bond strength and failure modes were evaluated. The bond strength of gutta‐percha/AH Plus and gutta‐percha/EndoSequence BC Sealer was not significantly different (P = 0.89). The presence or absence of smear layer did not significantly affect the bond strength of filling materials (P = 0.69). The mode of bond failure was mainly cohesive for all groups. In conclusion, the bond strength of the new bioceramic sealer was equal to that of AH Plus with or without the smear layer.     

IN VIVO EVALUATION OF THE SEALING ABILITY OF TWO ENDODONTIC SEALERS IN ROOT CANALS EXPOSED TO THE ORAL ENVIRONMENT FOR 45 AND 90 DAYS

This in vivo study evaluated the sealing ability of a resin-based sealer (AH Plus) and a zinc oxide-eugenol sealer (Endofill) in dogs'' teeth, exposed to the oral environment for 45 and 90 days. Forty eight lower incisors from 8 dogs were endodonticaly treated. A stratified randomization determined the sealer use in each root canal. All canals were filled using the lateral condensation technique. The excess filling material at the cervical portion of the root canal was sectioned, leaving a 10-mm obturation length inside the canal. Teeth were provisionally sealed with glass ionomer cement for 24 h and the canals were exposed to the oral environment for either 45 or 90 days. Therefore, the experimental groups were as follows: A45- AH Plus for 45 days; A90- AH Plus for 90 days; E45- Endofill for 45 days; and E90- Endofill for 90 days (n=12). After the experimental period, the dogs were killed and the lower jaw was removed. The incisors were extracted and the roots were covered with two coats of nail varnish. The teeth were immersed in India ink for 96 h and submitted to diaphanization. Dye leakage (in mm) was measured using stereomicroscopy (10x magnification). The results were statistically analyzed using two-way ANOVA and Tukey test for multiple comparisons (á = 0.05). Group E90 (2.03±0.94) showed significantly higher mean leakage value than all other groups (p<0.001). None of the sealers, in both study conditions, were able to prevent dye leakage.     

An in vitro study of the coronal leakage of two root canal sealers using an obligate anaerobe microbial marker

The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with lateral condensation of cold guttapercha with two root canal sealers. Sixty extracted human teeth with straight, single root canals were prepared using the modified double-flared technique with balanced force under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (40 teeth) and control groups (20 teeth). In the experimental groups, 20 teeth were obturated with lateral condensation of cold gutta-percha and AH26 sealer and 20 teeth were obturated with the same technique using TubliSeal EWT sealer. In the control groups, 10 teeth were obturated with the same technique either with AH26 or TubliSeal EWT sealer. These teeth were completely sealed to serve as negative controls. The remaining 10 teeth were not obturated and served as positive controls. The root surface of each tooth was sealed with nail varnish except the apical 2 mm. The coronal part of each root canal was sealed with the cut end of polypropylene tube and placed in a glass bottle containing sterile Fastidious Anaerobe Broth (FAB). Aliquots of 0.5 mL of FAB were injected into the polypropylene tube and the model system was centrifuged at 168 g. An inoculum of Fusobacterium nucleatum in FAB was placed in each coronal chamber at 7-day intervals and daily observations were made for bacterial growth in the apical reservoir for 12 weeks. All positive control teeth showed bacterial leakage within a week, while the negative control teeth remained uncon-taminated throughout the test period. All the experimental teeth exhibited leakage of bacterial metabolites within 12 weeks, ranging from 1 to 12 weeks. The mean time for complete leakage in the AH26 and the TubliSeal EWT groups was 8.4 and 8.2 weeks respectively. There was no statistically significant difference (P > 0.05) in leakage between the AH26 and the TubliSeal EWT groups.     

An in vitro study of apical and coronal microleakage of laterally condensed gutta percha with Ketac-Endo and AH-26

The purpose of this in vitro study was to compare both apical and coronal dye penetration when Ketac-Endo and AH-26 sealers were user with laterally condensed gutta percha. Crowns were removed from 28 teeth and the root canals were biomechanically prepared. The teeth were divided into two groups of 12 teeth. each and a control group of 4 teeth. Root canals in the two experimental groups were filled with laterally condensed gutta percha and either Ketac-Endo or AH-26 sealer. The ketac-Endo group had the coronal 3 mm of gutta percha and sealer removed and the resultant cavity was filled with Ketc-Endo alone. After the sealers had set, the root surfaces were coated with nail varnish except at the apex and at the coronal end. Positive control had no root fillings and were coated with nail varnish in the same manner while the negative controls were sealed apically and coronally with Cavit prior to apically and coronally with Cavit prior to sealing the entire external root surface with nail varnish. Specimens were placed in 2% methylene blue dye in a vacuum of 660 mm of mercury for five minutes and than left immersed for a further two days. The roots were vertically sectioned to determine the following mean levels of dye penetration: keta-Endo, 1.08 mm apically and 6.29 mm coronally; AH-26, 0.75 mm apically and 6.67 mm coronally. Positive controls had total leakage and negative controlls had no leakage. This study demonstrated that the apical and coronal seals obtained with Ketac-Endo and AH-26 were not significantly different although the apical seal obtained with each material was significantly better than the corresponding coronal seal.