Apical sealing of root canal fillings performed with five different endodontic sealers: analysis by fluid filtration

In vitro comparison of the marginal adaptation of cold ceramic sealer with the single-cone obturation technique versus AH-26 sealer with the lateral compaction technique in single-canal teeth

OBJECTIVES

This study aimed to compare the marginal adaptation of a cold ceramic (CC) sealer with the single-cone obturation technique with that of an AH-26 sealer with the lateral compaction technique in single-canal teeth.

MATERIALS AND METHODS

In this in vitro experimental study, the root canals of 24 extracted single-rooted single-canal teeth were instrumented to F3 files by the crown-down technique and randomly assigned to 2 groups (n = 12). The root canals were obturated with a CC sealer and single-cone obturation technique with 4% gutta-percha in group 1 and with an AH-26 sealer and lateral compaction technique with 2% gutta-percha in group 2. After 4 weeks of storage at room temperature and 100% humidity, the root ends were sectioned horizontally 3 mm from the apex, and the mean linear distance between the root filling material and the root dentinal wall was measured under a scanning electron microscope (SEM). Comparisons were made by the Mann‒Whitney test (alpha = 0.05).

RESULTS

The mean linear distance (gap) was significantly smaller in the CC sealer/single-cone group than the AH-26/lateral compaction group (6.72 ± 2.57 vs. 12.94 ± 4.82 μm, P = 0.001).

CONCLUSION

Marginal adaptation was significantly higher with the CC sealer and single-cone obturation technique than with the AH-26/lateral compaction technique, suggesting the suitability of the CC sealer and single-cone obturation technique for a hermetic seal in single-canal teeth.

Effect of different root canal irrigants on push-out bond strength of two novel root-end filling materials

BACKGROUND

The aim of this in vitro study was to evaluate push-out bond strength of different root-end filling materials using various irrigant solutions.

METHODS

A push-out bond strength test was performed to evaluate the bond strength of two experimental root-end filling materials: namely, nano-hybrid mineral trioxide aggregate (MTA) and polymethyl methacrylate (PMMA) cement filled with 20% weight nano hydroxyapatite (nHA) fillers compared to conventional MTA. The irrigant solutions employed were sodium hypochlorite (NaOCl) in concentrations 1%, 2.5% and 5.25% and 2% chlorhexidine gluconate (CHX) followed by application of 17% ethylene diamine tetra-acetic acid (EDTA). A freshly extracted sixty single-rooted human maxillary central incisors were used. The crowns were removed, the canal apex was widened to simulate immature teeth. Each type of irrigation protocols was performed. After application and setting of the root-end filling materials, a slice of one mm thickness was cut transversely from the apical end of each root. Specimens were stored for 1 month in artificial saliva and were subjected to a push-out test to evaluate the shear bond strength. Data were analyzed using two-way ANOVA and Tukey test.

RESULTS

The experimental nano-hybrid MTA showed the highest significant push-out bond strength values when irrigated by NaOCl at several concentrations (1%, 2.5% and 5.25%) (P< 0.05). Meanwhile, irrigation with 2% CHX resulted in highest bond strength values in nano-hybrid white MTA (18 MPa) and PMMA filled with 20% weight nHA (17.4 MPa) with nonsignificant difference between them (p = 0.25). In each root-end filling material, irrigation with 2% CHX led to the highest significant bond strength, followed by NaOCl 1%, while the least significant bond strength was produced after irrigation with NaOCl 2.5% and 5.25% (P< 0.05).

CONCLUSION

Considering the limitations of this study, it may be concluded that the application of 2% CXH and 17% EDTA provides superior push-out bond strength to root canal dentin compared with irrigation with NaOCl irrigants and 17% EDTA, experimental nano-hybrid MTA root-end filling material provides enhanced shear bond strength than conventional micron-sized MTA root-end filling material.

The influence of calcium silicate-based cement on osseous healing: A systematic review and meta-analysis

Objectives

The purpose of this systematic review was to analyze the effect of commercially available calcium silicate-based bioactive endodontic cement (BEC) on treatment outcome when used as root repair material in human permanent teeth and to compare it with traditional materials.

Methods

PubMed, Embase, and Cochrane Library were searched until June 2020. Randomized clinical studies and observational studies with a minimum 1-year follow-up and sample size of at least 20 were included. Risk of bias (ROB) was assessed using Cochrane's ROB tool and the National Institutes of Health Quality Assessment Tool.

Results

Thirty-nine studies were included in the systematic review. Majority of the studies used mineral trioxide aggregate. The pooled success rate for BEC was estimated by a random-effects method as 90.49% (95% confidence interval [CI]: 88.4992.34, I2 = 54%). Eleven studies comparing BEC with traditional materials were included in the meta-analysis. The use of BEC significantly improved the treatment outcome when compared to traditional materials with odds ratio (OR) = 2.15 (95% CI: 1.57-2.96, I2 = 0.8%, P = 0.433).

Conclusion

Very low-to-moderate-quality evidence suggests that the use of BEC as root repair material enhanced the treatment outcome. High-quality studies are required for the newer BEC to establish their clinical performance. Registration: PROSPERO CRD42020211502.

Evaluation of dentin penetration of three different endodontic sealers in the presence and absence of the smear layer

INTRODUCTION

A sealer's ability to effectively and stably penetrate the dentinal tubules is an essential factor for selecting an effective root canal obturation material. Evaluation of the sealers' penetration into the dentinal tubules provides valuable data in the endodontic treatment outcome.

Laboratory study of tissue repair of resin-based endodontic sealers in critical surgical defects

Filling materials should be restricted to the root canal space. However, sometimes it is impossible to control the apical extrusion, in this case, the fate of the filling material and the result of the treatment will depend on its physicochemical properties and biocompatibility.

Structural, fluoride release, and 3D interfacial adhesion analysis of bioactive endodontic sealers

The experimental bioactive sealers were synthesized by incorporating fluoridated-nano-bioactive glass (F-nBG; 2.5 and 5wt%) in AH Plus^® (Dentsply DeTrey, Konstanz, Germany) sealer and denoted as AH-FBG2.5 and AH-FBG5, respectively. Structural pattern, setting time, flowability, and water sorption analysis were performed. The fluoride release behavior was evaluated periodically over the course of 40 days using inductively coupled plasma optical emission spectroscopy. For sealing ability, post-extraction single-rooted teeth were obturated with sealers. The percentage of voids and sealing ability were evaluated periodically using micro-computed tomography (micro-CT) followed by push-out bond strength. The Fourier transform infrared spectra showed a change in peak height with an increase in the concentration of fillers. The setting time, flowability, and water sorption of experimental groups were within the acceptable clinical range. The fluoride release, sealing ability, and bond strength of experimental sealers were significantly high. The experimental sealers have potential to overcome sealing ability issues of sealers.

Comparative evaluation of apical sealing ability of different root canal sealers

Purpose

The aim of this study was to compare the short and long term apical sealing ability of different root canal sealers.

Materials and methods

Fifty-five extracted human anterior single-root teeth were used. The coronal part of each tooth was removed and the root canals were prepared with NiTi rotary instruments. Teeth were divided into 5 study groups; Group I: MTA Fillapex (Angelus, Brazil); Group II: Sealapex (Sybron-Kerr, Romulus, MI, USA) and Group III: AH Plus (Dentsply, Konstanz, Germany) (n=15) and negative and positive control groups (n=5). The quality of root canal sealing was assessed by a fluid filtration method performed at 24 h and 180-day time intervals. Kruskal Wallis and Mann Whitney U tests were used to compare the groups.

Results

At 24 h evaluation, MTA Fillapex presented significantly less microleakage than the Sealapex and AH Plus (p<0.05). At long term interval (180-day), Sealapex and AH Plus presented significantly less microleakage than the MTA Fillapex (p<0.05).

Conclusion

Sealapex and AH Plus showed significantly better sealing abilities than MTA Fillapex in the long term.

In Vitro Assessment of Apical Leakage of Bioceramic Endodontic Sealer with Two Obturation Techniques

Purpose:

The aim of this study was to evaluate the apical sealing ability of Total Fill BC sealer and AH Plus sealer with single cone and continuous wave condensation obturation techniques using dye extraction leakage method.

Materials and Methods:

Eighty-four extracted human single-rooted teeth with round canals were decoronated at 12 mm length and instrumented using crown down technique with the iRace rotary file system to apical file size 40 with 0.04 taper. The roots were randomly divided into four experimental groups (n=20). Group (A1) contained roots which were obturated with Total Fill BC sealer with a single cone. Group (A2) contained roots which were obturated using Total Fill BC sealer with continuous wave condensation. Group (B1) contained roots which were obturated using epoxy resin sealer (AH Plus) with a single cone. Group (B2) contained roots which were obturated using AH Plus sealer with continuous wave condensation.

Apical microleakage was assessed with dye extraction method where the absorbance of leaked 1% methylene blue dye was measured using a spectrophotometer. The absorbance values were converted into concentrations, and the data was analyzed using One way ANOVA test.

Results:

The mean dye concentration values were 0.012, 0.016, 0.011 and 0.015 for Group A1, Group A2, Group B1 and Group B2, respectively.

One-way ANOVA indicated no significant difference in dye leakage between the investigated groups (F = 0.938).

Conclusion:

With the limitation of the study, it was concluded that Total Fill BC was equivalent to AH Plus in apical sealing ability when using single cone or continuous wave condensation. The single cone can provide a similar apical seal of canal filling as can be achieved by using continuous wave condensation methods, in the round canal.

Influence of ultrasonics on the penetration depth of AH plus, acroseal, and EndoREZ root canal sealers: An in vitro study

Aim

The aim of this study is to evaluate the effect of ultrasonic activation on the penetration depth of AH Plus, Acroseal, and EndoREZ sealers into dentinal tubules using Confocal laser microscopy.

Methods

A total of 60 single-rooted teeth were prepared and divided into three groups on the basis of the type of sealer used (G1: AH Plus, G2: Acroseal and G3:EndoREZ). Each group was further subdivided into two equal subgroups on the basis of ultrasonic activation of sealers and nonactivation. Teeth were obturated and coronally sealed with GIC. Horizontal sections at 2 mm, 4 mm, and 6 mm from the apex were obtained, and the depth of sealer penetration into the dentinal tubules was measured using confocal laser scanning microscopy. Statistical analysis was performed using Students unpaired t-test, ANOVA, and Tukey's multiple comparison test.

Results

Within the three groups, ultrasonically activated subgroups showed significantly (P < 0.05) higher depth of sealer penetration. Among the groups, Group 1 showed significantly (P < 0.05) higher depth of sealer penetration than Group 2 and Group 3 while the difference between Group 2 and Group 3 was not significant (P > 0.05).

Conclusion

The use of ultrasonic activation with AH Plus sealer showed better results.

Effect of Nd:YAG and Diode Lasers on Apical Seal of Root Canals Filled with AH Plus and Mineral Trioxide Aggregate-Based Sealers

OBJECTIVES

Laser irradiation, as an adjunct to root canal preparation, may increase the success rate of endodontic treatments. This study aimed to assess the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) and diode lasers on the apical seal of the root canals filled with AH Plus® and mineral trioxide aggregate (MTA)-based sealers.

MATERIALS AND METHODS

This in-vitro experimental study was conducted on 96 single-rooted, single-canal extracted human teeth with closed apices. The root canals were prepared by using ProTaper® rotary instruments and were randomly divided into six groups (n=16): 940-nm diode laser and AH Plus® sealer (group 1), Nd:YAG laser and AH Plus® sealer (group 2), AH Plus® sealer (group 3), 940-nm diode laser and MTA-based sealer (group 4), Nd:YAG laser and MTA-based sealer (group 5), MTA-based sealer (group 6), as well as positive and negative control groups. A bacterial leakage model was used for microleakage assessment. Qualitative assessment was done by using a scanning electron microscope (SEM). Data were analyzed by two-way analysis of variance (ANOVA) at the significance level of 0.05.

RESULTS

There were statistically significant differences between the experimental and control groups (P=0.002). The laser-treated groups showed a lower apical microleakage compared to the non-laser-treated groups, although the difference was not statistically significant (P>0.05). No significant differences were noted between the two lasers in terms of the apical microleakage, irrespective of the type of sealer (P>0.05).

CONCLUSIONS

Laser irradiation, as an adjunct to root canal preparation, has no significant effect on the level of apical microleakage.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

Evaluating the Accuracy of Two Microleakage Assessment Methods for Mineral Trioxide Aggregate and Calcium-enriched Mixture Cement

INTRODUCTION

Multiple methods for evaluating microleakage have been introduced over the years, but there has been no agreement as to which technique will give more accurate results. The aim of this study was to compare the accuracy and results of fluid filtration and marginal adaptation methods for mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement apical plugs.

METHODS AND MATERIALS

A total of 250 single-rooted human teeth were collected. The teeth were decoronated, the root canals were prepared and open apex condition was stimulated by passing #1 to 4 Peeso Reamer drills from apical foramen. Five teeth were selected as the positive and negative controls and the rest of the samples were randomly allocated to two groups of MTA and CEM cement plugs. In each group, apical plug was placed into the canal. After the apical plugs were completely set, microleakage and marginal adaptation of the samples were evaluated using fluid filtration method and scanning electron microscopy (SEM), respectively. The obtained results were analyzed by independent-samples t test.

RESULTS

Gap between plug and dentin walls and air bubbles displacement was higher in MTA group compared to the CEM cement group, though this difference between MTA group and CEM cement group was not statistically significant. Conclusion: According to the obtained results, it seems that there is a direct relationship between the two methods of microleakage assessment.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study

Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Experimental polyethylene-hydroxyapatite carrier-based endodontic system: an in vitro study on dynamic thermomechanical properties, sealing ability, and measurements of micro-computed tomography voids

The dynamic thermomechanical properties, sealing ability, and voids formation of an experimental obturation hydroxyapatite-reinforced polyethylene (HA/PE) composite/carrier system were investigated and compared with those of a commercial system [GuttaCore (GC)]. The HA/PE system was specifically designed using a melt-extrusion process. The viscoelastic properties of HA/PE were determined using a dynamic thermomechanical analyser. Human single-rooted teeth were endodontically instrumented and obturated using HA/PE or GC systems, and then sealing ability was assessed using a fluid filtration system. In addition, micro-computed tomography (μCT) was used to quantify apparent voids within the root-canal space. The data were statistically analysed using one-way anova and post hoc tests. The HA/PE composite exhibited important modulus and damping changes with an increase of temperature. The HA/PE system was more flexible than GC as the modulus of GC appeared to be significantly higher than that of HA/PE as a result of the high positive glass transition temperature (Tg ). However, HA/PE and GC presented similar sealing abilities. In conclusion, because sealing ability and voids formation were comparable between the tested materials, the experimental HA/PE system may be considered a suitable alternative material for root-canal obturation. Moreover, HA/PE possesses specific viscoelastic behaviour and lower melting points, which may facilitate root-canal retreatments.

Efficacy of Biodentine as an Apical Plug in Nonvital Permanent Teeth with Open Apices: An In Vitro Study

The aim of this study was to evaluate the apical microleakage of Biodentine and MTA orthograde apical plugs and to compare the effect of thickness of these biomaterials on their sealing ability. A total of eighty maxillary anterior teeth were used. The apices were removed by cutting with a diamond disc (Jota, Germany) 2 mm from the apical root end in an attempt to standardize the working length of all specimens to 15 ± 1 mm. Both materials were placed in 1–4 mm thickness as apical plugs root canal. Root canal leakage was evaluated by the fluid filtration technique. One-way ANOVA was used in order to determine normality of dispersal distribution of parameters; thereafter, results were analyzed by Kolmogorov-Smirnov test. Overall, between microleakage values of MTA and Biodentine regardless of apical plug thickness, no difference was observed. In terms of plug thickness, a statistically significant difference was observed between the subgroups of MTA and Biodentine (p < 0.05). The apical sealing ability of Biodentine was comparable to MTA at any apical plug thickness.

In Vitro Evaluation of Apical Sealing Ability of HEROfill® Obturator Versus Cold Lateral Condensation in Curved Root Canals

OBJECTIVES

This study aimed to assess and compare the apical sealing ability of HEROfill® Soft-Core system and lateral condensation technique in fine curved canals using the fluid filtration method.

MATERIALS AND METHODS

Forty human mesiobuccal root canals of mandibular first molars with 25° to 40° curvatures were instrumented to an apical size 30/0.04. Roots were randomly assigned to two experimental groups of 15, designated as groups A and B. Two control groups, each containing five teeth, served as positive and negative controls. Group A was obturated using lateral condensation technique and group B with the HEROfill® Soft-Core system. The groups were tested for microleakage using an in vitro fluid filtration apparatus with 0.5 atm pressure at zero, two, four, six, eight and 10 minutes. Independent t-test was used to analyze the microleakage data.

RESULTS

The mean and standard deviation (SD) values for fluid microleakage in the lateral condensation group were 0.58±0.49 μL/min, 0.68±0.35 μL/min, 0.74±0.22 μL/min, 0.71±0.29 μL/min and 0.60± 0.29 μL/min at two, four, six, eight and 10 minutes, respectively. The mean and SD values for fluid microleakage in the HEROfill® group were 0.53±0.42 μL/min, 0.67±0.34 μL/min, 0.69±0.26 μL/min, 0.73±0.33 μL/min and 0.63±0.26 μL/min at two, four, six, eight and 10 minutes, respectively. The difference between the lateral condensation and HEROfill® groups was not statistically significant at two (P=0.776), four (P=0.909), six (P=0.562), eight (P=0.861) or 10 (P=0.765) minutes.

CONCLUSION

The HEROfill® system and cold lateral condensation technique were equally effective for apical sealing of curved canals.

Comparison of fluid filtration and bacterial leakage techniques for evaluation of microleakage in endodontics

BACKGROUND

Apical leakage assessment is a way to compare the efficiency of a filling material to seal the apical region of the tooth. Many microleakage testing techniques have been introduced through the years, but there has been no agreement as to which technique gives the most accurate results. The aim of this study was to compare the accuracy of fluid filtration and bacterial leakage techniques in the assessment of the apical sealing ability of mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM).

MATERIALS AND METHODS

A sample of 34 extracted single-rooted human teeth were selected and prepared. The samples were divided in to 2 experimental groups. The apical 3 mm of each root was resected at 90° to its long axis and root end preparation was done with ultrasonic tips to a depth of 3 mm and filled with MTA and CEM, respectively. Assessment of apical sealing ability was done with fluid filtration technique and bacterial leakage technique along 90 days with Enterococcus faecalis bacteria. Mann-Whitney U-test and Chi-square test were used to analyze the data using SPSS (SPSS Inc., Chicago, IL, USA). P less than 0.05 was considered as significant.

RESULTS

There was no significant difference in apical sealing ability between MTA and CEM in bacterial leakage and fluid filtration techniques. Samples which had bacterial leakage showed higher leakage values by fluid filtration technique.

CONCLUSION

Both techniques showed same results and there was no significant difference between fluid filtration and bacterial leakage techniques in assessment of apical microleakage.

Use of calcium-containing endodontic sealers as apical barrier in fluid-contaminated wide-open apices

PURPOSE

The sealing of wide-open apex roots is still a challenge and requires the use of apical barrier techniques. The aim was to evaluate ex vivo the sealing and the apical morphology of 3 commercial calcium oxide (CaO)-containing sealers - namely, 2 zinc oxide-based (CRCS and Sealapex) and a calcium silicate MTA-based (TechBiosealer Endo) - placed in wet root canals with artificial wide-open apices.


METHODS

Thirty human single-rooted teeth were shaped with Protaper and an artificial open apex (diameter size 110) was created. Each root was inserted in a custom-designed support containing simulated body fluid (Hank's balanced salt solution, HBSS) at the bottom simulating the presence of periapical fluid in the canal. Each sealer (TechBiosealer Endo, CRCS, Sealapex) was compacted to the apical 5 mm and the filled roots stored in HBSS at 37°C. The sealing was evaluated as microinfiltrated fluid since 24 hours up to 6 months using a high-precision digital fluid flow meter. The sealers were also studied for setting time in HBSS, calcium releasing (statistical analysis by 2-way ANOVA followed by Student-Newman-Keuls test, P<0.05) and surface morpho-chemistry by ESEM-EDX and OM analysis.


RESULTS

All sealers showed a stable seal. TechBiosealer Endo maintained a better seal than the other materials (P<0.05) and ESEM-EDX and OM analyses showed the presence of apatite deposits.


CONCLUSIONS

The clinical use of hydraulic hydrophilic MTA-based sealers can be recommended to stop/reduce the fluid flow rate through the apex. The artificial apical barrier in wet wide apices is a suitable technique able to seal wet root canals.

Apical Sealing Ability of a Novel Material: Analysis by Fluid Filtration Technique

AIM

The aim of this study is to evaluate the sealing ability of Biodentine(TM), which is new calcium-silicate based dental cement and has endodontic indications similar to those of MTA.

METHODS

The study sample consists of 21extracted human mandibular anterior teeth. The teeth were submitted to root-end preparation and instrumented up to file #40 by step back technique and randomly divided into 3 study groups (n=7): White MTA Angelus(TM) (Angelus, Angelus Odontológica, Londrina, PR, Brazil), Biodentine(TM) (Septodont, SeptodontSpecialités, Saint-MaurdesFosses, France) and the controls. The length of dye penetration between the filling material and tooth structure was measured in millimetres, using a calibrated stereo microscope (Leica MZ75, Germany) at 20× magnification under the same conditions. One-way Analysis of Variance (ANOVA) was used to indicate differences between the experimental groups and the controls. In addition, Tukey Multiple Comparisons Test was used to indicate differences within each group.

RESULTS

The results showed that none of the groups were completely sealed. The mean and standard deviation for dye penetration in Biodentine(TM) group was 0.63±0.20 and in MTA Angelus(TM) group, it was 0.26±0.25. Regarding the comparisons between each group, significant differences were not observed (P=0.0193). The comparison between materials only found a significant difference only between MTA Angelus(TM) and Biodentine(TM) (P<0.05).

CONCLUSIONS

This study evaluated the possibility of Biodentine(TM)'s sealing ability and marginal adaptation, since no studies are available on Biodentine. However, further in vitro and in vivo investigations should be conducted to determine the suitability of Biodentine(TM) for clinical application.

Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

OBJECTIVES

To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin.

MATERIAL AND METHODS

Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05.

RESULTS

There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices.

CONCLUSIONS

There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems.

Assessment of the sealing abilities of several root canal sealers and filling methods

OBJECTIVE

To evaluate the sealing abilities of two root canal sealers (epoxy resin-based AH Plus(®) and polydimethylsiloxane-based GuttaFlow(®)) and of five root filling techniques (lateral condensation, matched taper single gutta-percha point, laterally condensed-matched taper gutta-percha point, Thermafil(®) and continuous wave of condensation), using a bacterial leakage model.

MATERIALS AND METHODS

One hundred and seventy-four single-rooted human teeth were randomly divided into 10 test groups (n = 15) and two control groups (n = 12). The roots that were filled with the test material, using the different root filling techniques, were mounted in a two-chamber bacterial leakage model and Enterococcus faecalis was added to the upper chambers. The lower chambers of all of the specimens were checked every day during the test period (100 days). The day of turbidity was recorded for each sample. Statistical analysis was performed using the Kaplan-Meier and log-rank tests.

RESULTS

There was no significant difference between the epoxy resin-based and the polydimethylsiloxane-based sealers, irrespective of the filling techniques used (p > 0.05). The continuous wave of condensation technique was found to be superior to the other techniques (p < 0.05). The difference between the other groups was insignificant (p > 0.05).

CONCLUSIONS

AH Plus and GuttaFlow sealers showed similar levels of sealing ability. The continuous wave of condensation technique had the best sealing capability when compared to the other techniques.

Ex vivo microbial leakage after using different final irrigation regimens with chlorhexidine

Objective:

To assess the influence of final irrigation protocols with chlorhexidine in the coronal leakage of Enterococcus faecalis in filled root canals.

Material and Methods:

Seventy single-root canals from extracted teeth were prepared using ProTaper instruments. The irrigation protocol accomplished an alternating irrigation with 5 mL of 2.5% sodium hypochlorite (NaOCl) and 17% EDTA between each file. The teeth were randomly divided into four experimental groups (n=15) according to the final irrigation regimen: group 1, without final irrigation; group 2, irrigation with 10 mL 2.0% chlorhexidine (CHX); group 3, with a final application of EC40^TM; and group 4, irrigation with the combination (1:1) of 0.2% CHX + 0.1% cetrimide (CTR). All the teeth were mounted in a two-chamber apparatus and the coronal access was exposed to E. faecalis. The presence of turbidity in the BHI broth over a period of 180 days was observed. The Friedman test was used for statistical analysis.

Results:

EC40^TM varnish showed the least leakage at 180 days, and was statistically similar to 2% CHX. No significant differences were observed between the group without final irrigation and the 2% CHX group or 0.2% CHX + 0.1% CTR.

Conclusions:

In this ex vivo study, EC40^TM showed the longest delayed coronal leakage of E. faecalis, although without significant differences from 2% CHX.

Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

Objectives

To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin.

Material and Methods

Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05.

Results

There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi²=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices.

Conclusions

There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems.