Endodontic leakage studies reconsidered. Part I. Methodology, application and relevance

Sealing efficacy of mineral trioxide aggregate with and without nanosilver for root end filling: An in vitro bacterial leakage study

BACKGROUND

Various materials have been added to mineral trioxide aggregate to enhance its properties. This study was aimed to compare the sealing efficacy of MTA with and without nanosilver using bacterial leakage approach.

MATERIAL AND METHODS

Seventy canine teeth were prepared and obturated. Then, after apical resection, the root-end cavities were prepared by ultrasonic retrotips. Teeth were randomly divided into 4 groups containing two experimental groups (n=30) and two negative and positive controls (n=5). In group 1 and 2, root-end cavities were respectively filled with MTA and MTA with nanosilver (by 1% weight). Leakage assessment was carried out by bacterial leakage apparatus with Enterococcus faecalis species. Leakage comparison between experimental groups was done using Mann-Whitney test by Spss 16 software at significancy level of 0.05.

RESULTS

The median bacterial leakages for MTA and MTA with nanosilver were 19 and 2, respectively. The mean bacterial leakages for MTA and MTA with nanosilver were 30.06±28.67 and 9.66±14.25, respectively. Mann-Whitney test indicated that there was a significant difference in bacterial leakage day between two experimental groups (P=0.002).

CONCLUSIONS

Based on the findings of this in-vitro bacterial leakage study, adding nanosilver to MTA decreased its sealing ability. Key words:Root canal therapy, root canal obturation, root canal filling materials, nanosilver, MTA.

Solubility and bacterial sealing ability of MTA and root-end filling materials

Objective

To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials.

Material and Methods

The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO₂), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level.

Results

For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO₂, and both presented better results than ZOE (p<0.05).

Conclusion

MTA and CSC/ZrO₂ presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

The sealing ability of novel Kryptonite adhesive bone cement as a retrograde filling material

Background. This study evaluated the ability of Kryptonite bone cement in sealing retrograde cavities. Methods. The root canals of one hundred extracted human maxillary incisor teeth were instrumented up to master apical file #40 using Mtwo rotary system and obturated with gutta-percha and AHPlus sealer by cold lateral compaction method. The specimens were assigned to one control group and four experimental groups based on the retrograde filling materials (n=20). The specimens were immersed in 0.5% Rhodamine B solution for 48h. Then the specimens were divided longitudinally into two parts and the depth of dye penetration was assessed under ×10 magnification. Data were analyzed using one-way ANOVA and Bonferroni tests. Results. There were statistically significant difference between the experimental groups and the control group (P<0.05). There were no statistically significant differences between the experimental groups in dye penetration scores (P>0.05). Conclusion . Kryptonite cement provided optimal apical seal in a manner similar to MTA, amalgam and IRM when used as a retrograde filling cement.

In vitro evaluation of a newly produced resin-based endodontic sealer

OBJECTIVES

A variety of root canal sealers were recently launched to the market. This study evaluated physicochemical properties, biocompatibility, and sealing ability of a newly launched resin-based sealer (Dia-Proseal, Diadent) compared to the existing root canal sealers (AHplus, Dentsply DeTrey and ADseal, Metabiomed).

MATERIALS AND METHODS

The physicochemical properties of the tested sealers including pH, solubility, dimensional change, and radiopacity were evaluated. Biocompatibility was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. For microleakage test, single-rooted teeth were instrumented, and obturated with gutta-percha and one of the sealers (n = 10). After immersion in 1% methylene blue solution for 2 weeks, the specimens were split longitudinally. Then, the maximum length of staining was measured. Statistical analysis was performed by one-way analysis of variance followed by Tukey test (p = 0.05).

RESULTS

Dia-Proseal showed the highest pH value among the tested sealers (p < 0.05). ADseal showed higher dimensional change compared to AHplus and Dia-Proseal (p < 0.05). The solubility values of AHplus and Dia-Proseal were similar, whereas ADseal had the lowest solubility value (p < 0.05). The flow values of sealer in increasing order were AHplus, DiaProseal, and ADseal (p < 0.05). The radiopacity of AHplus was higher than those of ADseal and Dia-Proseal (p < 0.05). The cell viability of the tested materials was statistically similar throughout the experimental period. There were no significant differences in microleakage values among the tested samples.

CONCLUSIONS

The present study indicates that Dia-Proseal has acceptable physicochemical properties, biocompatibility, and sealing ability.

An in-vitro comparative study for assessment of apical sealing ability of Epiphany/AH Plus sealer with Resilon/gutta-percha root canal filling materials

AIMS AND OBJECTIVES

Endodontic treatment is directed to eliminate microbial challenges from the root canal system and to create a complete seal. The aim of this study was to assess the apical sealing ability of resin-based Epiphany-Resilon root canal filling system and to compare it with the sealing abilities of different combinations of AH Plus, gutta-percha, Epiphany, and Resilon.

MATERIALS AND METHODS

One hundred extracted human maxillary incisor roots were treated endodontically. The samples were divided into groups A, B, C, and D, with each group containing 25 samples. Group A: Canals obturated with gutta-percha and AH Plus sealer; Group B: Canals obturated with Resilon and Epiphany; Group C: Canals obturated with gutta-percha and Epiphany; Group D: Control group canals obturated with gutta-percha without a sealer. The sealing ability of each of the obturation techniques was tested using the dye penetration method followed by the clearing method using alcohol. Stereo microscope was used to measure the extent of dye penetration. Statistical data analysis was performed using analysis of variance and Tukey tests.

RESULTS

Microleakage was found in all the four groups. Apical extent of mean microleakage was maximum for gutta-percha, followed by Gutta-percha + AH-plus and Gutta-percha + Epiphany, and the least with Resilon + Epiphany. Statistically significant difference (P < 0.01) was seen in the apical leakage.

CONCLUSION

All the samples tested showed microleakage. The "Epiphany soft resin endodontic obturation system" showed a superior result compared to other obturation materials.

Modern Endodontic Principles. Part 5: Obturation

Once cleaning and shaping is complete the clinician must obturate the canal. There are many different materials and techniques available each with their own discrete advantages and disadvantages. Whichever technique is used, the goal is to seal the entire prepared length of the root canal. This paper describes how best this may be achieved. CPD/Clinical Relevance: It is incumbent on the clinician to ensure that once the canal has been prepared it is sealed from bacterial re-entry.

Effect of Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol on the Sealing Ability of Biodentine Apical Plug

INTRODUCTION

Teeth with immature apex are managed by establishing an apical plug using various materials and techniques. However, the use of previously placed intracanal medicament may affect the sealing ability of permanent filling material used as an apical plug.

AIM

To evaluate the effect of removal of previously placed Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol as an intracanal medicament on the sealing ability of the Biodentine as an apical plug.

MATERIALS AND METHODS

A total of 72 recently extracted human permanent teeth with single root were selected and stored in saline at room temperature. The crown portion of each tooth was removed at the level of cemento enamel junction; 14mm root length was taken as standard length. All the roots were submerged in 20% sulphuric acid up to 3 mm from the apex, for four days for root resorption. One sample was cut longitudinally to look for root resorption under stereo microscope. The canal preparation was done; the roots were kept in moist gauze after instrumentation. A total of 71 roots were randomly divided into three groups. GROUP 1:Calcium hydroxide paste, GROUP 2: Chlorhexidine digluconate, GROUP 3: Camphorated Monochlorophenol (CMCP). The medicaments were removed with stainless steel hand files and 0.5% sodium hypochlorite irrigation. After removal of medicament Biodentine was placed in apical third of resorbed roots and the remaining portion of the canals was filled with gutta-percha. All the 71 roots were analysed with fluid filtration method for evaluating microleakage.

RESULTS

Comparing all the three groups statistically there was no significant difference. The mean values were found more for group 1 followed by group 2 & 3.

CONCLUSION

All the groups showed microleakage. Calcium hydroxide showed the maximum microleakage followed by Chlorhexidine digluconate and least with CMCP.

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.

Evaluation of root canal sealer filling quality using a single-cone technique in oval shaped canals: An In vitro Micro-CT study

The aim of this study was to evaluate and compare the presence of voids in oval root canals filled with different root canal sealers (EndoSequence BC Sealer, Smartpaste bio, ActiV GP) and to compare those with root canals filled with AH Plus sealer using micro-CT. In total, 40 freshly extracted human single-root maxillary premolars were used. Specimens instrumented with the EndoSequence NiTi rotary instrument were assigned randomly into four groups. In each group, root canals were filled with single-cone gutta-percha and one of the tested sealers. Each specimen was then scanned using micro-CT at a voxel resolution of 13.47 μm. Proportions of sections with voids in cross-sectional images and void volumes for each sealer were calculated in the apical, middle, and coronal thirds. Differences according to root canal sealers were evaluated statistically using the Kruskal-Wallis test and the Mann-Whitney U-test at a significance level of 5%. The analysis showed a decrease in void formation in the apical third, with a significant difference between the apical and coronal thirds among bioceramic sealers, ActiV GP, and AH Plus (p < 0.05) but no significant difference between the apical and middle thirds or between the middle and coronal thirds was found for the sealers tested (p > 0.05). All root canal sealers tested resulted in voids. The bioceramic sealers (EndoSequence BC Sealer, Smartpaste bio) produced similar voids which had the fewest in the apical third of root canals among the sealers tested which can be related due to root canal anatomy variations.

Apical filling characteristics of carrier-based techniques vs. single cone technique in curved root canals

OBJECTIVES

In this in vitro study, we assessed filling characteristics (adaptation, homogeneity, sealer percentage, position of the carrier) of warm and cold obturation methods in curved root canals.

MATERIALS AND METHODS

A reciprocating method was used to prepare 90 curved roots (25 ° average curvature) to an apical size of 25.08. They were then obturated with either (A) Guttafusion (VDW, Munich, Germany), (B) Thermafil (Maillefer, Ballaigues, Switzerland) or (C) single cone technique using 25.08 gutta-percha (VDW) and sealer (2Seal easymix) (n = 30 each group). Five sections in 1-mm steps were obtained from each root, beginning 1 mm short of the apex. The percentage of voids in contact with root canal walls (PVO), the proportion of voids per area (PVA) and the percentage of sealer per area (PSA) were measured.

RESULTS

Little to no differences between Guttafusion and Thermafil were seen in curved root canals with respect to adaptation and homogeneity in the apical region. Both methods showed significantly better adaptation and homogeneity than the single cone technique. The proportion of sealer was significantly greater when roots were obturated with Guttafusion than with Thermafil, but both warm obturation techniques had significantly smaller sealer areas than the single cone technique.

CONCLUSIONS

Compared to the single cone technique, a more favourable root canal filling with less sealer could be expected from both warm obturation techniques in curved root canals.

CLINICAL RELEVANCE

The easier-to-handle Guttafusion leads to comparable results as Thermafil in curved root canals.

Comparison of the effect of MTAD and conventional irrigation agents on apical leakage and push-out bond strength of root canal filling

The aim of this study was to evaluate the effect of MTAD (a mixture of tetracycline isomer, an acid, and a detergent) and conventional irrigation agents on the apical leakage and push-out bond strength of root canal filling and to correlate the apical leakage and push-out bond strength. Root canals of 120 maxillary central incisors were prepared with a ProTaper file up to F3 and distributed to six groups. Saline, 1% NaOCl, 17% EDTA, 17% EDTA/1% NaOCl, and 2% chlorhexidine (CHX) solutions were used between each file change, and 5 mL of the same irrigating solution was used for the final flush. In the MTAD group, the root canals were irrigated with 1.3% NaOCl between each file and 5 mL of MTAD for the final flush. All the root canals were filled with AH Plus sealer and gutta-percha cones. Apical leakage was evaluated using a fluid transport system. After the apical leakage test, each tooth was prepared for the push-out assessment. The statistical analysis revealed that the irrigation solutions had no effect on the apical leakage of the root canal fillings (p = 0.258). The root fillings of the groups irrigated with MTAD showed significantly lower push-out bond strength values than the other groups (p < 0.001). These commonly used irrigating solutions did not affect the apical leakage of the root canal sealer. MTAD reduced the bond strength of the root canal sealer to the root canal dentin.

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.

Applying liquid chromatography-tandem mass spectrometry to assess endodontic sealer microleakage

The objective of this study was to describe a new method for the quantitative analysis of a microleakage of endodontic filling materials. Forty extracted single-rooted teeth were randomly divided into three experimental groups. After root canal shaping, the experimental groups were filled using the lateral condensation technique with the Epiphany system (G1), with gutta-percha + Sealapex (G2), and with gutta-percha + AH Plus (G3). Each root was mounted on a modified leakage testing device, and caffeine solution was used as a tracer (2000 ng mL-1, pH 6.0), applied in the coronal direction towards the tooth apex, creating a hydrostatic pressure of 2.55 kPa. Presence of caffeine in the receiving solution was measured after 10, 30, and 60 days, using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). None of the groups presented microleakage at 10 days. At 30 days, G2 and G3 showed similar infiltration patterns (means: 16.0 and 13.9 ng mL-1, respectively), whereas G1 showed significantly higher values (mean: 105.2 ng mL-1). At 60 days, leakage values were 182.6 ng mL-1 for G1, 139.0 ng mL-1 for G2, and 53.5 ng mL-1 for G3. AH Plus showed the best sealing ability and HPLC-MS/MS showed high sensitivity and specificity for tracer quantification.

Effect of post space preparation on the sealing ability of mineral trioxide aggregate and Gutta-percha: A bacterial leakage study

Aim:

The purpose of this study was to evaluate the effect of post space preparation on the sealing ability of teeth obturated with mineral trioxide aggregate (MTA) and Gutta-percha.

Materials and Methods:

Fifty intact human mandibular premolars, after decoronation and biomechanical preparation, were randomly divided into three experimental groups. In Group A (n = 10), the canals were obturated with Gutta-percha using cold lateral compaction technique, followed by immediate post space preparation. In Group B (n = 10), the canals were obturated with 8 mm of MTA and in Group C (n = 10), sectional obturation with 4 mm of MTA was done, followed by delayed post space preparation. All specimens were subjected to bacterial leakage analysis, and the occurrence of turbidity was checked.

Results:

All specimens in the lateral compaction group leaked. The mean number of days at which leakage was observed in Groups A, B and C were 18.5 days, 93.6 days and 95.5 days.

Conclusions:

MTA can be considered as an alternative to Gutta-percha as an apical third restorative material for teeth indicated for post and core, as it demonstrates better-sealing ability compared with Gutta-percha. Further, the removal of set MTA for post space preparation does not disrupt the integrity of the remaining apical MTA.

Microleakage of Single-Cone Gutta-Percha Obturation Technique in Combination with Different Types of Sealers

Introduction:

Various materials and methods have been recommended for successful root canal obturation. The aim of this experimental in vitro study was to compare the sealing ability of three root canal sealers AH-26, glass ionomer cement (GIC) and zinc oxide eugenol (ZOE) in single gutta-percha obturating system.

Methods and Materials:

Seventy extracted single-rooted human teeth were decoronated. The teeth were randomly divided into 3 experimental groups (n=20) and 2 positive and negative control groups. After root canal preparation, canals were obturated with single-cone method using either AH-26, GIC and ZOE. The leakage was evaluated using the dye penetration method. The samples were sectioned to evaluate the linear leakage using a stereomicroscope. The data were analyzed using the One-way ANOVA test.

Results:

All the specimens in the positive control group showed evidence of leakage. In the experimental groups, the lowest leakage scores were observed in the AH-26 group (P<0.05). However, there were no statistically significant differences between GIC and ZOE samples (P=0.676).

Conclusion:

AH-26 showed a superior seal and less microleakage compared to the two other materials in single gutta-percha obturating system.

Quantitative microleakage analysis of root canal filling materials in single-rooted canals

The purpose of this study was to analyze the sealing ability of different root canal filling materials over a 6-week period using a glucose penetration model. Forty-six recently extracted human premolars were used in this study. The root canals were enlarged to 40/0.06. Prepared canals were randomly assigned into four groups (n = 10) as follows: Group 1, Gutta-Percha (GP)/AH Plus with cold lateral compaction; Group 2, GP/AH Plus with continuous wave compaction; Group 3, RealSeal SE obturation system; and Group 4, OrthoMTA. The remaining specimens were used as positive and negative controls, and all specimens underwent thermocycling (10,000; 5-55 °C). The sealing ability of all samples was evaluated at 24 h, 1, 2, 4, and 6 weeks using a quantitative glucose leakage model, and scanning electron microscope (SEM) images were taken. A mixed effect analysis using R statistical language was performed. Groups 1, 2, and 4 showed low leakage levels during experimental periods. Group 3 showed low leakage levels for the first 2 weeks; however, the leakage level was significantly increased after 2 weeks compared to negative control group (p < 0.05). In the SEM results, Group 3 showed imperfect dentin bonding, whereas Group 4 showed calcium silicate hydrate short tags, which are formed at the access of the dentin tubules. GP/AH Plus and OrthoMTA showed less microleakage than RealSeal SE obturation system when used as root canal filling materials. Traditional GP/AH Plus sealer and the newly developed OrthoMTA are more appropriate for ideal sealing of the root canals.

The Temperature Dependence of Micro-Leakage between Restorative and Pulp Capping Materials by Cu Diffusion

We used the Cu ions for the leakage analysis between pulp capping and restorative materials. Theoretically, Cu has more advantages than Ag ions due to their smaller radii (r_Cu²⁺=73 pm and r_Ag²⁺=94 pm), lower mass density (d_Cu=8.96 g/cm³ and d_Ag=10.49 g/cm³) and higher radio opacity which can be more useful by X-ray or EDX detectors, cheaper price and more abundance in planet when compared with Ag element which is generally used in the leakage studies. The micro leakage between dental restorations and pulp capping materials has been determined by using Micro Computed Tomography, Scanning Electron Microscopy and EDX analysis. It is found that the leakage has temperature dependent mechanism which increases with the increasing temperature. As a result, using Cu solution for leakage studies in dentine is an effective and easy method which can be used in dental science.

Sealing ability of three hydrophilic single-cone obturation systems: An in vitro glucose leakage study

Aim:

The aim of this study is to compare the corono-apical sealing ability of three single-cone obturation systems using a glucose leakage model.

Materials and Methods:

A total of 90 freshly extracted human maxillary single-rooted teeth was selected, and their crowns were cut. The root canal of each sample was instrumented using a rotary crown down technique and then divided into four experimental (n = 20 each) and two control groups (n = 5 each). Samples in the experimental groups were filled as follows: Group 1, cold lateral condensation using gutta-percha/AH Plus; group 2, single-cone C-points/smart-paste bio-sealer; group 3, single-cone bio-ceramic (BC) impregnated gutta-percha/endo-sequence BC sealer; group 4, single-cone Resilon/RealSeal SE after 7 days, the sealing ability of root canal fillings was tested at different time intervals using glucose leakage model. Glucose leakage values were measured using a spectrophotometer and statistically analyzed.

Results:

The four experimental groups presented significantly different glucose leakage values at all test periods (P < 0.05). At the end of the observation period, the cumulative glucose leakage values of groups 2 and 3 were significantly lower than those of groups 1 and 4 (P < 0.05).

Conclusion:

C-points/smart-paste Bio and BC impregnated gutta-percha/endo-sequence BC sealer combinations provided the superior sealing ability over the lateral condensation technique.

The Effect of Thickness on the Sealing Ability of CEM Cement as a Root-end Filling Material

Background and aims. Different materials have been used for root-end filling during surgical endodontic treatment. The aim of this in vitro study was to evaluate the dye penetration in different thicknesses of calcium enriched mixture (CEM) cement as root-end filling material. Materials and methods. Following root canal filling in 70 extracted human single-rooted premolar teeth, the apical 3 mm of their root-ends was resected; the root-end cavities with depths of 1, 2 and 3 mm were prepared by ultrasonic retrotips and filled with CEM cement. After setting of cement, the roots were immersed in 2% Rhodamine B and the dye leakage was measured under stereomicroscope (×16) using Image J software. The data were analyzed by one-way ANOVA and Bonferroni post hoc tests at 5% significance level. Results. The means and standard deviations of dye penetration in the 1, 2, and 3 mm groups were 3395.5±1893.4, 3410.4±1440.5, and 2581.6±1852.9 μm, respectively. The one-way ANOVA analysis indicated significant differences (P < 0.001); however, the Bonferroni post hoc test revealed that only the positive control group differed significantly from the experimental groups (P < 0.001). Conclusion. The findings demonstrated CEM cement to have an adequate root-end sealing ability in 3-mm thickness.

Quantitative microleakage analysis of endodontic temporary filling materials using a glucose penetration model

OBJECTIVE

The purpose of this study was to analyze the sealing ability of different temporary endodontic materials over a 6-week period using a glucose penetration model.

MATERIALS AND METHODS

Standardized holes were formed on 48 dentin discs from human premolars. The thicknesses of the specimens were distributed evenly to 2 mm, 3 mm and 4 mm. Prepared dentin specimens were randomly assigned into six groups (n = 7) and the holes in the dentin specimens were filled with two kinds of temporary filling materials as per the manufacturers' instructions as follows: Caviton (GC Corporation, Tokyo, Japan) 2 mm, 3 mm, 4 mm and IRM (Dentsply International Inc., Milford, DE) 2 mm, 3 mm, 4 mm. The remaining specimens were used as positive and negative controls and all specimens underwent thermocycling (1000; 5-55°C). The sealing ability of all samples was evaluated using the leakage model for glucose. The samples were analyzed by a spectrophotometer in quantitative glucose microleakage test over a period of 6 weeks. As a statistical inference, a mixed effect analysis was applied to analyze serial measurements over time.

RESULTS

The Caviton groups showed less glucose penetration in comparison with the IRM groups. The Caviton 4 mm group demonstrated relatively low glucose leakage over the test period. High glucose leakage was detected throughout the test period in all IRM groups. The glucose leakage level increased after 1 week in the Caviton 2 mm group and after 4 weeks in the Caviton 3 mm and 4 mm groups (p < 0.05).

CONCLUSIONS

Caviton had better sealing ability than IRM in the glucose penetration model during 6 weeks. Temporary filling of Caviton to at least 3 mm in thickness is necessary and temporary filling periods should not exceed 4 weeks.

The Effect of Root Canal Irrigation with Combination of Sodium Hypo-chlorite and Chlorhexidine Gluconate on the Sealing Ability of Obturation Materials

Objectives:

The aim of this study was to evaluate the effect of the precipitate that was formed by combining Sodium Hypochlorite (NaOCl) and Chlorhexidine Gluconate (CHX) on the sealing ability of root canal obturation materials.

Materials and Methods:

The fluid filtration method was conducted on a total of 100 roots. Samples were randomly divided into two control (n=5) and three experimental groups (n=30). The samples in group 1 were irrigated with 1.5 mL of 2.5% NaOCl, and then the smear layers of the teeth were removed by 17% EDTA, while the specimens of group 2 were irrigated by 1.5 mL of 2.5% NaOCl and 1.5 mL of 2% CHX; after the smear layer removal, a final flush with 1.5 mL of 2.5% NaOCl was performed. The samples of group 3 were irrigated the same as group 1 but after the smear layer removal canals were irrigated again with 1.5 mL of 2.5% NaOCl and then a final flush with 1.5 mL of 2% CHX was performed. Teeth were obturated with gutta-percha and AH26 sealer and after seven days, microleakage was evaluated by the fluid filtration technique. The results were analyzed by the ANOVA and Tukey's test.

Results:

The samples in group 3 had significantly greater microleakage compared to teeth in group 1, 2 (p<0.05), and the specimens in group 1 showed significantly less amount of microleakage than samples in group 2, 3 (p<0.05).

Conclusion:

The presence of the precipitate that is formed due to interaction between NaOCl and CHX has negative effect on the sealing ability of gutta-percha and AH26 sealer.

Effects of ultrasonic root-end cavity preparation with different surgical-tips and at different power-settings on glucose-leakage of root-end filling material

Aim:

The aim of this in vitro study was to evaluate the effects of different ultrasonic surgical-tips and power-settings on micro-leakage of root-end filling material.

Materials and Methods:

The root canals were instrumented using rotary-files and were filled with tapered gutta-percha and root canal sealer using a single-cone technique. The apical 3 mm of each root was resected and the roots were divided into six experimental groups; negative and positive control groups. Root-end cavities were prepared with diamond-coated, zirconum-nitride-coated and stainless-steel ultrasonic retro-tips at half-power and high-power settings. The time required to prepare the root-end cavities for each group was recorded. Root-end cavities were filled with Super-EBA. Leakage values of all samples evaluated with glucose penetration method on 7, 14, 21 and 28^th days. The results were statistically analyzed with Kruskal-Wallis and Hollander-Wolfe tests.

Results:

The mean time required to prepare retro cavities using diamond-coated surgical tip at high-power setting was significantly less than other groups (P < 0.01). There were no statistically significant differences in the glucose penetration between the groups at first and second weeks (P > 0.01). Diamond-coated surgical tip showed the least leakage at high-power setting at 3^rd and 4^th weeks (P < 0.01).

Conclusions:

Under the conditions of this study, cavity preparation time was the shortest and the leakage of the root-end filling was the least when diamond-coated retro-tip used at high-power setting.

Microleakage evaluation of adhesive systems following pulp chamber irrigation with sodium hypochlorite

Background and aims. This in vitro study evaluated the effect of delaying composite resin restorative procedures bonded with total-etch and self-etch adhesive systems on microleakage following root canal irrigation with sodium hy-pochlorite (NaOCl) solution. Materials and methods. The roofs of pulp chambers and roots (1&ndash;2 mm below furcation) of 40 human first molar teeth were cut and pulp tissues completely removed. The teeth were randomly divided into two main groups (n = 20). Group E (experimental) was irrigated with 5% NaOCl and group C (control) was left untreated. For the experimental group, after obturation of root canals with gutta-percha and sealing the cavity with Cavit, the specimens were stored in artificialsaliva for two weeks. Then each group was divided into two subgroups according to the total-etch or self-etch adhesive application protocol: Scotchbond Multi-Purpose and Clearfil SE Bond. The specimens were restored with composite resin using each bonding agent: Z250 and Clearfil Photo Core, respectively. Fluid filtration method was used for evaluation of microleakage. Data was analyzed using two-way ANOVA ( α= 0.05). Results. Two types of dentin adhesive systems showed no statistically significant differences in microleakage (P = 0.77). NaOCl-treated groups demonstrated significantly higher microleakage values compared to the non-NaOCl-treated groups (P= 0.001). The interaction between the two factors was not significant (P = 0.78). Conclusion. Differences in inlay temperature had no effect on microleakage. CAD/CAM inlays had lower cement thick-ness than laboratory-made inlays, but this was not related to their microleakage.

Intraorifice sealing ability of different materials in endodontically treated teeth: An in vitro study

Background:

Microbial contamination of the pulp space is one of the major factors associated with endodontic failure. Thus, in addition to a three dimentional apical filling a coronal seal for root canal fillings has been recommended.

Aim:

The present study was conducted to evaluate and compare the intra-orifice sealing ability of three experimental materials after obturation of the root canal system.

Materials and Methods:

Fourty single rooted mandibular premolars were decoronated, cleaned, shaped and obturated. Gutta-percha was removed to the depth of 3.5 mm from the orifice with a heated plugger. Ten specimens each were sealed with Light Cure Glass Ionomer Cement (LCGIC), Flowable Composite (Tetric N-Flow), and Light Cure Glass Ionomer Cement with Flowable Composite in Sandwich Technique along with a positive control respectively and roots submerged in Rhodamine-B dye in vacuum for one week. Specimens were longitudinally sectioned and leakage measured using a 10X stereomicroscope and graded for depth of leakage.

Results:

According to the results of the present study LC GIC + Tetric N Flow demonstrated significantly better seal (P < 0.01) than LC GIC. However there was no statistically significant difference in leakage (P > 0.01) between Tetric N-Flow and LCGIC+Tetric N-Flow groups.

Conclusion:

In the current study LCGIC+Tetric N-Flow was found to be superior over other experimental materials as intra-orifice barriers.

Shrinkage of backfill gutta-percha upon cooling

INTRODUCTION

The temperature and related shrinking kinetics of gutta-percha injected from heat guns are not known; therefore, we investigated them in this study.

METHODS

The temperatures of 3 different backfill gutta-percha brands extruded from 3 commercially available heat guns set to 200°C were studied. To validate the results, temperature development of 1 gutta-percha brand injected from a heat gun during a simulated backfilling procedure was assessed in single-rooted human teeth containing thermocouples in a water bath of 37°C. These values were compared with the counterparts obtained in a tabletop testing device for shrinkage at an ambient temperature of 37°C. Using this device, linear shrinkage upon cooling was assessed for all 3 gutta-percha brands under investigation. Results were compared by parametric statistics (alpha = .05).

RESULTS

The temperatures of extruded gutta-percha differed significantly (P < .05) between heat guns and gutta-percha brands. Mean temperatures ranging between 57.6° ± 4.5°C and 103.9° ± 7.8°C could be observed with different combinations. The temperature of extruded gutta-percha in tabletop experiments equaled that observed in the root canals. However, the cooling of gutta-percha was (P < .05) faster in the tabletop measuring device compared with the root canal environment. Within the controlled temperature drop from 75°C to 37°C, the total shrinkage differed significantly (P < .05) between the 3 gutta-percha brands under investigation and ranged between 0.96% ± 0.20% and 2.31% ± 0.26% after 10 minutes (P < .05). Shrinking kinetics showed different patterns between the gutta-percha brands.

CONCLUSIONS

Gutta-percha designed for thermoplastic application shrinks quickly and extensively upon cooling.

Effect of ultrasonication on physical properties of mineral trioxide aggregate

Aim. To evaluate the effect on physical properties of Mineral Trioxide Aggregate (MTA) of using direct hand compaction during placement and when using hand compaction with indirect ultrasonic activation with different application times. Methods. One hundred acrylic canals were obturated in 3 increments with MTA in sample sizes of 10. One group was obturated by hand with an endodontic plugger and the remainder obturated with indirect ultrasonic application, with times ranging from 2 seconds to 18 seconds per increment. Microhardness values, dye penetration depths, and radiographs of the samples were evaluated. Results. As ultrasonic application time per increment increased, microhardness values fell significantly (P < 0.001) while dye penetration values increased (P < 0.001). Microhardness of MTA ultrasonicated for 2 seconds was significantly higher than hand compaction (P = 0.03). Most radiographic voids were visible in the hand-compacted group (P < 0.001), which also had higher dye penetration depths than the 2-second ultrasonicated samples. Ultrasonication of MTA for 10–18 seconds resulted in significantly more voids than 2–8 seconds of ultrasonication (P = 0.02). Conclusion. The use of ultrasonics with MTA improved the compaction and flow of MTA, but excessive ultrasonication adversely affected MTA properties. A time of 2 seconds of ultrasonication per increment presented the best compromise between microhardness values, dye penetration depths, and lack of radiographic voids.

Comparative Evaluation of Marginal Adaptation of Biodentine(TM) and Other Commonly Used Root End Filling Materials-An Invitro Study

AIM

The purpose of this investigation was to evaluate the marginal adaptation of three root-end filling materials Glass ionomer cement, Mineral trioxide aggregate and Biodentine(TM).

METHODOLOGY

Thirty human single-rooted teeth were resected 3 mm from the apex. Root-end cavities were then prepared using an ultrasonic tip and filled with one of the following materials Glass ionomer cement (GIC), Mineral trioxide aggregate (MTA) and a bioactive cement Biodentine(TM). The apical portions of the roots were then sectioned to obtain three 1 mm thick transversal sections. Confocal laser scanning microscopy (CLSM) was used to determine area of gaps and adaptation of the root-end filling materials with the dentin. The Post hoc test, a multiple comparison test was used for statistical data analysis.

RESULTS

Statistical analysis showed lowest marginal gaps (11143.42±967.753m2) and good marginal adaptation with Biodentine(TM) followed by MTA (22300.97±3068.883m(2)) and highest marginal gaps with GIC (33388.17±12155.903m(2)) which were statistically significant (p<0.0001).

CONCLUSION

A new root end filling material Biodentine(TM) showed better marginal adaptation than commonly used root end filling materials.

Ability of new obturation materials to improve the seal of the root canal system: a review

New obturation biomaterials have been introduced over the past decade to improve the seal of the root canal system. However, it is not clear whether they have really produced a three-dimensional impervious seal that is important for reducing diseases associated with root canal treatment. A review of the literature was performed to identify models that have been employed for evaluating the seal of the root canal system. In vitro and in vivo models are not totally adept at quantifying the seal of root canals obturated with classic materials. Thus, one has to resort to clinical outcomes to examine whether there are real benefits associated with the use of recently introduced materials for obturating root canals. However, there is no simple answer because endodontic treatment outcomes are influenced by a host of other predictors that are more likely to take precedence over the influence of obturation materials. From the perspective of clinical performance, classic root filling materials have stood the test of time. Because many of the recently introduced materials are so new, there is not enough evidence yet to support their ability to improve clinical performance. This emphasizes the need to translate anecdotal information into clinically relevant research data on new biomaterials.

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.

Laboratory validation of a new gas-enhanced dentine liquid permeation evaluation system

AIM

To validate a new automated dentine permeability testing platform based on pressure change measurements.

METHODOLOGY

A split chamber was designed allowing for concomitant measurement of fluid permeation and pressure difference. In a first test, system reliability was assessed by interposing a solid metal disk, embedded composite resin disks, or teeth by consecutively measuring eight times under standardized conditions. Secondly, the repeatability and applicability of the method was tested in a dentine wound model by using intact third molars: Class I (2 × 5 mm) and a full occlusal preparation as well a ceramic restoration were consecutively performed and repeatedly measured eight times each. In the last test, the system detection limit as well correlation between gas pressure difference and liquid permeation were evaluated: Again, third molars were used and occlusal preparations of increasing size (2 × 5, 3 × 5, 4 × 5, and 5 × 5 mm and full occlusal preparations, respectively) were made. Data was analyzed for the linearity of measurement, and R (2) values were calculated.

RESULTS

The embedding procedure allowed for perfect separation of the two chambers, and no significant variation in repeated measurements of evaluated samples for the respective treatments (p = 0.05) was found. The detection was 0.002 hPa/min for the pressure slope and 0.0225 μl/min for the fluid infiltration, respectively. The saline volume was highly correlating to the gas pressure changes (R (2) = 0.996, p < 0.0001).

CONCLUSIONS

The presented method is a reliable and exact tool to assess dentine permeability by nondestructive and repeatable measurements.

CLINICAL RELEVANCE

This method is suitable for measurements and comparison of the effectiveness of dentine wounds sealing materials.

Carrier-based root canal filling materials: a literature review

A review of the literature on the use of carrier based obturation materials focusing on Thermafil and Resilon based obturator (RealSeal 1) are presented in this article. The review addressed the history, apical leakage, coronal leakage, biocompatibility, sealing ability and clinical success of Thermafil and RealSeal 1. Based on the studies gathered, this review concluded that both treatment techniques (Thermafil and RealSeal 1) did not provide excellent apical sealing ability. More research should be done to try to overcome their main drawback, its sealing ability.

Effect of Nd: YAG laser on the apical seal after root-end resection and MTA retrofill: a bacterial leakage study

Laser irradiation has been investigated in terms of preventing leakage in retrofilled root canals. The aim of the present study was to evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on the bacterial leakage of mineral trioxide aggregate (MTA)-retrofilled roots. In this ex vivo experimental study, 90 single-rooted incisor teeth were filled with gutta-percha and AH26 sealer. The apical 3 mm of all the roots were resected and 3-mm retrocavities were prepared by an ultrasonic device. The specimens were randomly divided into two experimental (n = 25), one positive control (n = 10), and two negative control (n = 10) groups. In the laser + MTA group, the cavity walls were irradiated by Nd: YAG laser prior to MTA placement. In the MTA group, MTA was placed without laser irradiation. The root surfaces were covered with two layers of nail varnish except for the apical 2 mm. The specimens were then embedded in a bacterial leakage test system and examined daily for 90 days. Contamination periods were recorded. Data were analyzed by Kaplan-Meier and Mann-Whitney U tests (α = 0.05). Five teeth with and five teeth without laser irradiation underwent scanning electron microscopic evaluation. The specimens in the laser + MTA group were contaminated earlier than those in the MTA group (p < 0.05). Comparison of survival times between the two groups showed significant differences (p < 0.05). Nd: YAG laser irradiation can decrease the sealing capacity of MTA in comparison to the apical seal achieved by MTA without laser irradiation. Further studies are recommended to provide a better seal for the MTA-retrofilled teeth after laser irradiation.

Sealing Ability of MTA Used as a Root End Filling Material: Effect of the Sonic and Ultrasonic Condensation

Despite the excellent properties of mineral trioxide aggregate (MTA), the condensation technique may have some influence in its sealing ability. The purpose of this study was to compare the sealing ability of sonic and ultrasonic setting of MTA. Thirty-four extracted human teeth had their canals prepared and filled with Sealapex sealer and gutta-percha using the active lateral condensation technique. The teeth were rendered waterproof and apicoectomy performed at 3 mm from the apex. Root-end cavities (3.0 mm deep and 1.4 mm diameter) were prepared with diamond ultrasonic tips. The root-end cavities were filled with Pro-Root MTA® with ultrasonic vibration, sonic vibration or no vibration. The positive control group did not receive any material while the negative control group was totally rendered waterproof. After material set, the specimens were immersed in Rodhamine B for 24 h, under vacuum in the first 15 min, then washed, dried and split longitudinally for evaluating the infiltration at the dentin/material interface. Data were analyzed using ANOVA and Tukey's tests at 5% significance level. Sonic vibration promoted the lowest infiltration values (p<0.05). It was concluded that sonic vibration could be considered an efficient aid to improve the sealing ability of MTA when used as root-end filling material.

Qualitative SEM/EDS analysis of microleakage and apical gap formation of adhesive root-filling materials

Objective

The aim of this study was to compare the correspondence between gap formation and apical microleakage in root canals filled with epoxy resin-based (AH Plus) combined or not with resinous primer or with a dimethacrylate-based root canal sealer (Epiphany).

Material and Methods

Thirty-nine lower single-rooted human premolars were filled by the lateral condensation technique (LC) and immersed in a 50-wt% aqueous silver nitrate solution at 37ºC (24 h). After longitudinal sectioning, epoxy resin replicas were made from the tooth specimens. Both the replicas and the specimens were prepared for scanning electron microscopy (SEM). The gaps were observed in the replicas. Apical microleakage was detected in the specimens by SEM/energy dispersive spectroscopy (SEM/EDS). The data were analyzed statistically using an Ordinal Logistic Regression model and Analysis of Correspondence (α=0.05).

Results

Epiphany presented more regions containing gaps between dentin and sealer (p<0.05). There was correspondence between the presence of gaps and microleakage (p<0.05). Microleakage was similar among the root-filling materials (p>0.05).

Conclusions

The resinous primer did not improve the sealing ability of AH Plus sealer and the presence of gaps had an effect on apical microleakage for all materials.

Evaluation of apical sealing ability of four different sealers using centrifuging dye penetration method: an in vitro study

AIM

The aim of this in vitro study was to evaluate the apical seal obtained with four root canal sealers AH 26, Sealapex, Endoflas FS and AH Plus, with lateral condensation.

MATERIALS AND METHODS

Sixty root canals were prepared using the step-back technique. The specimens were divided into four experimental groups of 12 teeth and two control groups of 12 teeth. The experimental groups were obturated by laterally condensed gutta-percha with one of the tested sealers and control groups were obturated without any sealer. Methylene blue dye penetration with centrifuging method was used to evaluate the apical sealing ability. The quantitative apical leakage of each specimen was measured after 2 weeks.

RESULTS

The results showed no significant differences between all groups except between AH Plus and Endoflas FS (<0.05). AH Plus showed significantly less leakage than Endoflas FS.

CONCLUSION

AH Plus showed the least leakage compared to AH 26, Sealapex and Endoflas FS.

Evaluation of the antibacterial effect of calcium hydroxide in combination with three different vehicles: An in vitro study

Introduction:

Antimicrobial activity of interappointment intracanal medications is an important consideration in endodontics. Considering the fact that calcium hydroxide (CH) cannot sterilize the root canal system, completing its antimicrobial spectrum seems necessary. The aim of this study was to compare the antibacterial activity of CH combined with three different vehicles in root canal system.

Materials and Methods:

In this in vitro experimental study, 61 freshly extracted human single rooted teeth were used. After chemo-mechanical preparation, the teeth were dressed with CH in combination with: G1: Distilled water (DW); G2: 5.25% sodium hypochlorite; G3: 0.2% chlorhexidine solution. All teeth were mounted in a 2-chamber apparatus. After sterilization, the coronal chamber was exposed to bacteria and the apical chamber was filled with broth for 90 days. Leakage was recorded when turbidity was observed in broth. Mean times of leakage and turbidity percentage were recorded for each group. Data were analyzed by One Way ANOVA test (α=0.005).

Results:

The highest mean time of contamination was for chorhexidine/CH combination (M=66.76 days), and the lowest was for DW/CH combination (M=40.29 days). Statistically significant difference was observed between G3 and G1 (P=0.042), but the difference between G2 and G3 (P=0.76) or G1 and G2 (P=0.18) were not significant. 88.23% of the samples of G1, 70.58% of G2, and 64.70% of G3 were contaminated after 3 months.

Conclusion:

As an intracanal medication, the chlorhexidine/CH combination had significantly more antibacterial activity than DW/CH combination.

Effects of three different irrigating solutions and KTP laser irradiation on apical leakage: an electrochemical study

OBJECTIVE

The purpose of this study was to evaluate the effect of three different irrigating solutions (17% EDTA, 10% citric acid and 2.5% NaOCl) and KTP laser irradiation on apical leakage using an electrochemical method.

MATERIALS AND METHODS

Sixty extracted single-rooted human teeth with mature apices were instrumented up to a size 35 K-file. After using each file and before proceeding to the next, canals were irrigated with 2 ml of 2.5% NaOCl. All teeth were then randomly divided into four groups. In group 1, the root canals were irrigated with a final flush of 17% EDTA. In group 2, the root canals were irrigated with a final flush of 10% citric acid. In group 3, the root canals were irradiated with KTP laser at 1 W, 4.45 J/cm(2). In group 4, the root canals were irrigated with a final flush of 2.5% NaOCl. The root canals were then filled using the cold lateral condensation method. Apical leakage was evaluated using an electrochemical method over a period of 10 days. Data were analysed using Tukey HSD and Friedmann tests with p = 0.05 as the level for statistical significance.

RESULTS

The 17% EDTA and 10% citric acid groups had statistically less apical leakage than the 2.5% NaOCl group at days 7, 8, 9 and 10 (p < 0.05); however, no significant differences were found between the tested groups at the other time intervals (p > 0.05). No significant difference was found between the KTP laser group and other groups tested at all time intervals (p > 0.05).

CONCLUSION

All groups were unable to eliminate apical leakage. However, final irrigation with 17% EDTA and 10% citric acid following root canal preparation reduced postobturation apical leakage compared with 2.5% NaOCl irrigation. When KTP laser and the other three irrigants were compared, no significant difference was found.

Effect of Synthetic Tissue Fluid on Microleakage of Grey and White Mineral Trioxide Aggregate as Root-End Filling Materials: An in vitro study

OBJECTIVES

The success of endodontic surgery has been shown to depend partly on the apical seal. Grey mineral trioxide aggregate (GMTA) produces hydroxyapatite twice as often as white mineral trioxide aggregate (WMTA) when suspended in a phosphate buffered saline (PBS) solution. The aim of this in vitro study was to compare the microleakage phenomenon of gray and white mineral trioxide aggregates as root-end filling materials after immersion in synthetic tissue fluid (STF).

METHODS

55 single-rooted extracted maxillary anterior human teeth were divided into two experimental groups of 20 teeth each, plus 3 groups of 5 teeth each as two negative and one positive control groups. The root canals were cleaned, shaped, and laterally compacted with gutta-percha. The root ends were resected and 3 mm deep cavities were prepared. The root-end preparations were filled with GMTA or WMTA in the experimental groups. Leakage was determined using a dye penetration method. Data were analysed using analysis of variance (ANOVA) at the 0.05 level of significance.

RESULTS

The mean dye leakage was 0.40 ± 0.1 mm for GMTA and 0.50±0.1 mm for WMTA groups, respectively. There was no significant difference between the two experimental groups (P = 0.14).

CONCLUSION

Despite the different properties and behaviours of GMTA and WMTA in STF, there were no significant differences in microleakage when using GMTA or WMTA.