Particles and molecules in endodontic leakage

Comparative evaluation of sealing ability and adaptation of gel form of MTA to dentinal walls: an in-vitro study

CONTEXT

Mineral Trioxide Aggregate (MTA) is a calcium silicate-based cement that potentially exhibits improved washout resistance when carboxymethyl chitosan or gelatin is incorporated. Gel-form MTA is a novel mineral trioxide aggregate formulated using construction industry-based technology. The present study was conducted to comparatively evaluate the sealing ability and adaptation to dentinal walls of gel-form MTA.

MATERIALS AND METHODS

This in-vitro study consisted of two groups: gel-form MTA and the conventional powder-liquid MTA. 10 samples per group were used for each of the tested parameters. Adaptation of the MTA to the dentinal walls was tested under the light microscope and measured using Image J software. Sealing ability was evaluated using a single aerobic bacterial leakage model. Appropriate statistical analysis was done for the obtained data. Adaptation of the MTA was analyzed using independent t-test and Friedman test, whereas the bacterial leakage was analyzed using chi-square test.

RESULTS

On comparison of the adaptation property at coronal and apical thirds, there was no statistically significant difference between the groups (p = 0.071 and p = 0.638, respectively). However, while comparing the same in the middle one-third of the root, lesser gaps were identified in the gel-form MTA group (p = 0.013). One sample belonging to the conventional powder-liquid MTA group showed significant turbidity during bacteria leakage evaluation (p = 0.001) with the presence of E. faecalis in the count of 103 colony forming units/milliliter.

CONCLUSION

The gel-form MTA shows a better adaptation to the dentinal walls at the middle third of the root and exhibits better sealing ability against bacterial leakage when tested for E. faecalis. The adaptation of gel-form MTA at coronal and apical third of the root was comparable to the conventional powder-liquid MTA.

In vitro comparative evaluation of apical leakage using a bioceramic sealer with three different obturating techniques: A glucose leakage model

Context

Bioceramic sealers have improved sealing ability by forming an interfacial apatite layer that chemically bonds the sealer and radicular dentin thus decrease apical leakage.

Aim

This study aims to evaluate and compare the apical leakage of Cerafill RCS bioceramic sealer and gutta percha when used with three different obturating techniques.

Materials and Methods

Thirty-four extracted single-rooted premolars were decoronated and prepared up to size F3. Then, the specimens were randomly divided into 3 experimental groups (n = 10) cold lateral obturation technique, warm vertical obturation technique, single-cone obturation technique, positive and negative control groups (n = 2), according to the obturation technique used along with a bioceramic sealer. To evaluate apical leakage, all specimens were mounted in a glucose leakage model and assessed at 7 and 14 days using an ultraviolet-visible spectrophotometer.

Statistical Analysis

The results were subjected to ANOVA/Kruskal-Wallis ANOVA; followed by post hoc analysis using Bonferroni correction.

Results

Significant differences were found in the cumulative leakage of all the three experimental groups. Significantly higher leakage was found in groups obturated using single-cone obturation technique as compared to warm vertical compaction technique at both 7 and 14 days.

Conclusions

Warm vertical compaction showed a better sealing result than single-cone obturation techniques at all observation periods.

Methodologies used for testing the sealability of endodontic temporary fillings in vitro: A narrative review

Introduction

The ability of the temporary filling to seal endodontic access cavities may be crucial for the success of endodontic treatment. Numerous in vitro studies have investigated the sealability of the temporary fillings used in endodontic treatments. However, in vitro sealability studies have been criticized for their inconsistent results and questionable clinical relevance. Some journals have imposed moratoriums on publishing such studies to encourage researchers to test their validity and clinical relevance. Since the implementation of this moratorium, little progress has been made in this field. To further encourage researchers to investigate the reliability of these studies, this review presents an overview of the methodologies of studies that examine the ability of temporary filling materials to seal the endodontic access cavity in vitro and discusses the criticisms of these studies in detail.

Materials and Methods

PubMed, Scopus, and Embase electronic databases were searched to identify studies that tested in vitro the ability of temporary filling materials to seal endodontic access cavities. Only original articles published in English between 01/01/1970 and 28/02/2022 were included.

Results

The search yielded 551 results. After removing duplicates and excluding studies that did not meet the inclusion criteria, 94 studies were included in this review.

Conclusion

Although clinical studies may be the best way to test the performance of temporary fillings, the ethical importance of conducting preliminary in vitro studies is undeniable. It seems that questioning the reliability of in vitro sealability studies is not based on sufficient scientific evidence and that the inconsistencies in the results of these studies may be due to differences in the methodological and clinically relevant variables between them, rather than due to their unreliability.

The Effect of Different Obturation Techniques in Primary Teeth on the Apical Microleakage using Endoflas: A Comparative In Vitro Study

Objectives

This study was carried out to quantitatively evaluate and compare the sealing ability of Endoflas by using different obturation techniques.

Materials and Methods

After 42 extracted primary maxillary incisors and canines were decoronated, their canals were instrumented with K files of size ranging from #15 to #50. In accordance with the obturation technique, the samples were divided into three experimental groups, namely, group I: endodontic pressure syringe, group II: modified disposable syringe, and group III: reamer technique, and two control groups. Dye extraction method was used for leakage evaluation. Data were analyzed using one-way ANOVA and Dunnett's T3 post hoc tests. The level of significance was set at p < 0.05.

Results

Endodontic pressure syringe had significantly less leakage than the modified disposable syringe and reamer techniques (p < 0.05). Meanwhile, no significant difference was found in the mean leakage between the modified disposable syringe and the reamer techniques.

Conclusion

Amongst all the techniques used in this study, endodontic pressure syringe could be preferred as an obturation technique in primary teeth when used with Endoflas obturation material because of its potential to provide good apical seal.

A New Mass Spectroscopy-Based Method for Assessing the Periodontal-Endodontic Interface after Intracanal Placement of Biomaterials In Vitro

Optimizing the interface between biomaterials and dental hard tissues can prevent leakage of bacteria or inflammatory mediators into periapical tissues and thus avoid alveolar bone inflammation. In this study, an analysis system for testing the periodontal-endodontic interface using gas leakage and subsequent mass spectrometry was developed and validated using the roots of 15 single-rooted teeth in four groups: (I) roots without root canal filling, (II) roots with an inserted gutta-percha post without sealer, (III) roots with gutta-percha post and sealer, (IV) roots filled with sealer only, and (V) adhesively covered roots. Helium was used as the test gas, and its leakage rate was found by measuring the rising ion current using mass spectrometry. This system made it possible to differentiate between the leakage rates of tooth specimens with different fillings. Roots without filling showed the highest leakage values (p < 0.05). Specimens with a gutta-percha post without sealer showed statistically significantly higher leakage values than groups with a filling of gutta-percha and sealer or sealer alone (p < 0.05). This study shows that a standardized analysis system can be developed for periodontal-endodontic interfaces to prevent biomaterials and tissue degradation products from affecting the surrounding alveolar bone tissue.

Comparison of Sealing Ability of Bioceramic Sealer, AH Plus, and GuttaFlow in Conservatively Prepared Curved Root Canals Obturated with Single-Cone Technique: An In vitro Study

Background:

Inadequate obturation techniques of the root canal system have been found to be the most frequent reason of failure post root canal treatment. An ideal endodontic sealer should fulfill all ideal requisites. The present study aimed to compare apical sealing ability between bioceramic (BC) sealer, GuttaFlow, and AH Plus.

Methodology:

One hundred and twenty-five curved roots of maxillary and mandibular third molar teeth with fully formed apex were collected for this study. The root canals were cleaned and shaped using a standard single-cone preparation to file at the established working length and divided into five groups of 25 each. Dye leakage was carried out. Group A: with GP, using EndoSequence BC sealer with conventional with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group B: with ceramic coated with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group C: with GP, using AH Plus sealer (Dentsply, De-Trey Konstanz, Germany) with 4% gutta-percha; Group D: with GuttaFlow bioseal (Roeko-Coltène/Whaledent, Langenau, Germany) with 4% Gutta-percha; and Group E is a negative control group. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The group AH Plus showed more leakage values than the GuttaFlow group and of two groups of BC sealer and negative control. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal.

In-vitro evaluation of microleakage of bioceramic root-end filling materials: A spectrophotometric study

Aim

To evaluate the microleakage of newer bioceramic root-end filling materials.

Material and method

Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 ​mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 ​mm. All teeth were stored in 2% methylene blue for 72 ​h followed by emersion in 65% nitric acid for the next 72 ​h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer.

Result

Microleakage was found to be increasing in this order: Biodentin ​< ​Bioaggregate ​< ​MTA Plus ​< ​MTA. No significant difference was found in the microleakage of Biodentin compared to that of Bioaggregate(p ​> ​0.01).

Conclusion

All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.

An In Vitro Comparative Evaluation of Apical Leakage Using Different Root Canal Sealers

Background

Successful endodontic therapy requires a fluid-tight apical seal. The aim of this in vitro study was to evaluate and compare the apical sealing ability of 3 root canal sealers: Apexit Plus, AH Plus, and Resilon/Epiphany sealers.

Material/Methods

Samples of 152 single-rooted teeth were divided into 2 test groups, and each group was divided into 3 subgroups based on the preparation and obturation technique. After preparation with the step-back technique, the first group of root canals were obturated with lateral gutta-percha compaction in combination with AH Plus sealer or Apexit Plus or with the Resilon/Epiphany system alone. In the second group, preparation was done with the crown-down technique and root canals were then obturated with Thermafil obturator in combination with AH Plus or Apexit Plus or with Resilon/Epiphany sealer alone. Apical leakage was determined using a dye leakage test observed with a stereomicroscope. The degree of dye leakage was assessed using the t test to comparing the arithmetic averages of the groups.

Results

In the groups prepared with the step-back technique, the average dye leakage was lower in samples obturated with Resilon/Epiphany, than in those filled with AH Plus/lateral gutta-percha compaction or Apexit Plus/lateral gutta-percha compaction. In groups prepared with the crown-down technique and obturated with the Resilon/Epiphany system, the average dye leakage was lower than in those filled with AH Plus/Thermafil obturation and those filled with Apexit Plus/Thermafil obturation.

Conclusions

Although all preparation and obturation techniques showed dye penetration, the crown-down technique paired with the Resilon/Epiphany system showed the least leakage.

Comparative evaluation of microleakage after root-end resection by erbium, chromium: Yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser and carbide bur with or without placement of mineral trioxide aggregate: An in vitro study

Background:

Root-end resection followed by retrofilling is one of the prime requisites to avoid apical microleakage.

Aim:

It comparatively evaluated the microleakage after root-end resection by erbium, chromium:yttrium, scandium, gallium, and garnet laser and carbide bur with or without placement of mineral trioxide aggregate (MTA).

Materials and Methods:

In this study, 60 maxillary central incisors were decoronated and biomechanically prepared. Out of 60 samples, 48 were included in the experimental group while the rest 12 were in the control group. The samples in the experimental group were obturated, whereas the samples in the control group were not obturated. The experimental group samples were divided into two: one group resected with the laser and the other half resected with carbide bur. These groups were further subdivided into two – one group retrofilled with MTA and the other half without MTA. The control group had both laser- and carbide bur-resected samples with positive and negative controls. All the samples were dyed, decalcified, and cleared. Digital photograph of each sample was taken, and the area of dye penetration was measured with the help of ImageJ software.

Statistical Analysis:

Analysis of variance and Tukey's test were done.

Results:

The highest microleakage was seen in carbide without MTA and the least was seen with laser with MTA.

Conclusion:

Laser-resected MTA-retrofilled samples showed minimum leakage.

The Repair of Furcal Perforations in Different Diameters with Biodentine, MTA, and IRM Repair Materials: A Laboratory Study Using an E. Faecalis Leakage Model

The aim of this study is to evaluate the microleakage of repair materials MTA, IRM, and Biodentine applied on furcal perforations with different diameters. One hundred and forty extracted human teeth were used in this study. The teeth were divided into 2 main groups (60 teeth in each) which were then divided into 3 subgroups (n = 20). The remaining 20 teeth were divided into 2 groups (10 in each) to serve as controls. The furcal areas of the teeth were perforated with #2 cylindrical burs in Group 1 whereas perforations were made using #4 cylindrical burs in Group 2. Each subgroup of both Groups 1 and 2 received ProRoot MTA (ProRoot, USA), Biodentine (Septodont), or IRM (Dentsply, USA) to repair the perforations. An experimental set-up was established to contaminate repaired perforations with E. Faecalis (ATCC29212). The turbidity of bacteria was observed on the 7th, 15th, 30th, and 45th days. The data was analysed by chi-square test (p > 0.05). The number of bacteria in the group perforated by bur #2 and closed by MTA was found to be lower than the other groups on the 7th day (p < 0.05). There was no statistical difference in the bacterial counts of other groups on the 15th, 30th, and 45th days (p > 0.05). ProRoot MTA was found to be more successful in the prevention of bacterial leakage compared to IRM and Biodentine in smaller perforations during the 1st week.

Importance and methodologies of endodontic microleakage studies: A systematic review

INTRODUCTION

It is very important to obtain a tight seal in obturated root canal, making it necessary to conduct clinical or laboratory studies on the sealability of endodontic materials. Different methodologies have been historically used to assess microleakage of different endodontic materials. The aim of the present study was to comprehensively review different material testing methods used in microleakage studies, their interpretation and importance in endodontic literature.

MATERIAL AND METHODS

A systematic search was conducted in Medline, Cochrane, and Web of Science databases. In addition, the reference lists of review articles on the topic were searched. No language restriction was applied. Two independent reviewers screened the article.

RESULTS

Microleakage is considered the single most important risk factor responsible for apical periodontitis. Dye penetration, dye diffusion, bacterial and endototoxin infiltration, fluid filtration, glucose, caffeine and protein infiltration, radioisotope penetration, animal studies, and electrochemical or 3D evaluation are different methodologies used to assess dental leakage. 91 out of 177 articles in the primary search were included in the study. These methods are very divergent in their viewpoints; that is why their results cannot be easily compared. It is necessary to standardize microleakage detection methods in order to more correctly evaluate the phenomena that are found between the root canal wall and the root canal filling materials.

CONCLUSIONS

All the methods are useful if studies are performed strictly with large sample sizes and proper control groups and if the technique can be standardized. Furthermore, more evaluations of the reliability of the methods are strongly recommended. Key words:Dental leakage, review, root canal, material testing methods, data interpretation.

Apical Microleakage of four Materials after Root End Resection (In Vitro Study)

Hermetic sealing of the apical area after root end resection is essential to the success of endodontic surgery. To compare microleakage after root end resection of the two bioceramic sealers without retrograde filling - Total Fill BC Sealer and MTA Fillapex, and two materials for retrograde filling-MTA and Biodentine, using the method of penetration of dye - 2% methylene blue. Forty eight extracted single-rooted human teeth were used in this study. The resection was made at 3 mm from the root tip at an angle of 90 degree to the long axis of the tooth. The teeth were divided into 4 groups: 1st group (n = 9) - root canal obturation with Total Fill BC Sealer without retrograde filling; 2nd group (n = 8) - root canal obturation with MTA Fillapex without retrograde filling. 3rd group (n = 10) - retrograde ultrasonic cavity preparation and filling with MTA. 4th group (n = 8) - retrograde ultrasonic cavity preparation and filling with Biodentine. The outer surface of the root was covered with two layers of varnish, with the exception of the apical 3 mm and then immersed in 2% methylene blue for 72 h. The degree of penetration of the dye is measured in millimeters. The data was entered and processed with the statistical package IBM SPSS Statistics 22.0. We reject the null hypothesis when p < 0.05. With significantly higher value is the arithmetic mean of the group with the root canal obturation with Total Fill BC Sealer without retrograde filling - 2,01 mm; versus a retrograde filling with MTA - 0,68 mm and Biodentin - 0,51 mm; and no statistically significant difference with the group root canal obturation with MTA Fillapex - 1,76 mm. In the four material microleakage dye was observed, but to varying degrees.

A comparison of apical sealing ability between GuttaFlow and AH plus: An in vitro study

Aims:

The present study aimed to compare apical sealing ability between GuttaFlow and AH Plus.

Materials and Method:

Eighty extracted human maxillary anterior teeth with fully formed apex and straight root were collected for this study. The root canals were cleaned and shaped using a standard step back preparation to size 60# master apical file at the established working length and divided into four groups: Group 1, GuttaFlow sealer with gutta-percha; Group 2, AH Plus sealer with gutta-percha; Group 3, positive control group (Teeth were instrumented and left without obturation); Group 4, negative control group (Teeth were totally coated with nail varnish) Dye leakage was carried out. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The GuttaFlow group had a mean leakage of 1.38 mm whereas AH Plus had a mean of 1.425 mm. The standard deviation of GuttaFlow and AH Plus were 0.3861 and 0.3226, respectively. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal. GuttaFlow and AH Plus showed no statistically significant difference in microleakage; the better result was shown by GuttaFlow.

Coronal Microleakage of the Resilon and Gutta-Percha Obturation Materials with Epiphany SE Sealer: An in-vitro Study

INTRODUCTION

The coronal leakage of bacteria and other irritants to the root canal system is one of the main factors that may result in clinical failure and affect the long term success of endodontic treatment. The Resilon/Epiphany obturation system has been developed as an alternative to gutta-percha and traditional sealers.

AIM

This study aimed to evaluate and compare the coronal leakage between Resilon obturation material and gutta-percha using the same sealer.

MATERIALS AND METHODS

In this in-vitro study, 72 freshly extracted single-rooted human teeth were used, and were sectioned at CEJ with 13mm length. The roots were randomly divided into four groups. In Group I, 30 roots were obturated using Resilon and Epiphany SE sealer, Group II, 30 roots were obturated using gutta-percha and Epiphany SE. Group III and Group IV, 12 roots were used as control groups (positive and negative). The coronal leakage was measured using the dye penetration technique. Data were statistically analysed by a One-Way ANOVA test.

RESULTS

There was a significant difference between the two experimental groups where Resilon revealed less microleakage than gutta-percha group (p <0.05).

CONCLUSION

Resilon is a suitable replacement for gutta-percha on the basis of its increased resistance to microleakage, but it failed to provide complete hermetic coronal sealing.

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.

Porosity and sealing ability of root fillings with gutta-percha and BioRoot RCS or AH Plus sealers. Evaluation by three ex vivo methods

AIM

To investigate the ability of BioRoot RCS, a tricalcium silicate-based root canal sealer and AH Plus to effectively fill the root canals of contralateral teeth using three evaluation methods, and to investigate also the correlation between the methods.

METHODOLOGY

The prepared root canals of ten pairs of contralateral mandibular premolar teeth were filled with gutta-percha and sealer using lateral compaction. The percentage of voids within the root canal was assessed by micro-computed tomography, whilst sealing ability was investigated by fluid transport and leakage of fluorescent microspheres. The interaction of sealer with dentine, and sealer penetration were assessed by confocal microscopy. The void volume, fluid flow, microsphere leakage and sealer interaction with dentine for both materials were compared. Nonparametric (Mann-Whitney) tests were used to compare the % void and fluid transport of the two sealers. Spearman correlation was used to assess the pairwise relationships between the techniques. The level of significance was set to 0.05.

RESULTS

BioRoot RCS exhibited significantly more percentage of voids than AH Plus. There was no difference in fluid flow and microsphere penetration. BioRoot RCS exhibited a different pattern of sealer penetration and interaction with the dentine walls compared to AH Plus. For both materials, the pairwise correlations between the three techniques were close to zero, indicating weak relationships.

CONCLUSIONS

MicroCT analysis revealed a higher void volume for BioRoot RCS. The other techniques did not show a difference between the sealing ability of the sealers. The correlation between the three ex vivo methods of assessment was weak demonstrating their complementarity rather than their concordance.

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.

Evaluation of coronal leakage and pathway of dye leakage after obturation with various materials for open apical foramina

The aim of this study was to investigate coronal leakage after obturation with mineral trioxide aggregate (MTA), resin-based sealer, and silicon-based sealer for open apical foramina and to evaluate pathway of leakage. Twenty-eight maxillary premolars were used, and instrumented to ISO size #80. Teeth were randomly divided into four groups as follows: Group A filled with MTA, Group B with gutta-percha and resin-based sealer, Group C with polymer-based material and resin-based sealer, and Group D with gutta-percha and silicon-based sealer. All samples were evaluated for coronal leakage with methylene blue solution and spectrophotometry. After leakage testing, samples were cut, and sections were observed. Dye leakage of Group A was significantly lowest among all groups at 15 days and 30 days. Defects which induced coronal leakage in resin-based sealer were observed at 7 mm from the apex. Coronal leakage after obturation with MTA for open apical foramina was significantly lower than resin-based sealer and silicon-based sealer.

Root-end filling with cement-based materials: An in vitro analysis of bacterial and dye microleakage

Background:

One ideal property of a root-end filling material is its apical sealing ability. The aim of this in vitro study was to assess bacterial and dye microleakage of white and gray mineral trioxide aggregate (WMTA and GMTA), Portland cement and calcium-enriched mixture (CEM) cement used as root-end filling material, and to assess the agreement between these two test methods.

Materials and Methods:

Fifty-four single-rooted teeth were used. The roots were randomly divided into four study and two control groups. After decoronation, root canals were instrumented and filled with gutta-percha and AH26 sealer. Root-ends were resected 3 mm above the root-end and 3 mm deep cavities were prepared. Root-end cavities were filled with each material. Enterococcus faecalis and methylene blue dye were used for determination of bacterial and dye leakage respectively. Data were analyzed using Fisher's Exact Test, one-way ANOVA, Kaplan-Meier analysis, and Cohen's Kappa.

Results:

There was 100% bacterial leakage in Portland cement and CEM cement, 58.3% in GMTA, and 91.7% in WMTA. GMTA showed significantly less bacterial leakage than Portland cement and CEM cement (P < 0.05). In those samples with leakage occurrence, times of observation of leakage were not significantly different; however, by survival analysis, the results of the GMTA group were significantly different from those of the CEM cement and Portland groups. The difference in complete dye leakage was not significant. There was poor agreement between dye and bacterial leakage methods.

Conclusion:

CEM cement provides leakage results comparable to other commonly used root-end filling materials such as WMTA.

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.

Evaluation of the sealing ability of resin cement used as a root canal sealer: An in vitro study

AIM

This study was designed to evaluate the apical seal of root canals obturated with resin cement as a root canal sealer and compare with that of the glass ionomer and zinc oxide eugenol sealers using a cold lateral condensation gutta-percha technique.

BACKGROUND

Successful root canal treatment requires three-dimensional obturation of the root canal system with nonirritating biomaterials. None of the available materials are capable of providing a fluid tight seal.

MATERIALS AND METHODS

The prepared teeth were randomly divided into three groups of 15 each to be obturated using three different sealers. Group I: zinc oxide eugenol (Tubliseal), Group II: Glass ionomer (Ketac Endo), and Group III: resin cement (C & B Superbond). All the specimens were stored in 100% relative humidity at 37° for 24 h. The specimens were placed in 2% methylene blue dye for 48 h and sectioned. The dye penetration was evaluated under a stereomicroscope.

RESULTS

The "Kruskal" Wallis test was carried out to test the equality of mean. All the specimens showed dye leakage, and there was a statistically significant difference (P < 0.0001) among the groups. The specimens in Group III showed a minimal leakage and the specimens in Group I showed a maximum leakage.

CONCLUSION

Resin cement sealed the root canals significantly better when compared with zinc oxide eugenol and glass ionomer sealers.

[Comparative evaluation of sealing ability of different obturation materials]

INTRODUCTION

Root canal filling materials are intended to prevent microleakage and passing of microorganisms and their toxins along the root canal space and into the periradicular tissues.

OBJECTIVE

Objective of this in vitro study was to evaluate and compare apical leakage of root canals obturated using a modified warm vertical condensation technique and different materials.

METHODS

Sixty-five extracted single-root teeth were prepared according to the crown-down/ step-back technique. Each canal was rinsed with 3% NaOCl during and after the preparation. The teeth were divided into 3 groups. Every group was obturated by the same technique, but with different materials: RealSeal system (SybronEndo), gutta-percha with AH Plus (Dentsply Maillefer) and gutta-percha with Acroseal sealer (Septodont). The remaining 20 teeth were in the control group. The teeth were immersed in 1% methylene blue for 72 hours. After that period, the roots were split longitudinally, and dye penetration was measured using a stereomicroscope.

RESULTS

Dye penetration occurred in all groups. The least dye penetration occurred in the RealSeal group (0.33 +/- 0.29 mm), while the highest dye penetration occurred in the Acroseal group (1.11 +/- 0.52 mm). According to the Student's t-test, Acroseal showed significantly more leakage (p < 0.001) than RealSeal and AH Plus materials. The microleakage of RealSeal system was not significantly different (p > 0.05) from that of AH Plus sealer with gutta-percha.

CONCLUSION

The results suggested that new material Resilon (RealSeal) and conventional combination AH Plus with guttapercha had the least apical dye penetration and provided the best sealing.

Microleakage of various root filling systems by glucose filtration analysis

OBJECTIVE

The aim of this study was to evaluate the microleakage of Resilon + Epiphany, EndoRez, Activ GP, and conventional AH Plus + gutta-percha technique using the glucose filtration model.

STUDY DESIGN

One hundred twenty maxillary incisors were divided into 5 experimental and 2 control groups. After root canal shaping, the experimental groups were filled with AH Plus + gutta-percha (lateral compaction), Resilon + Epiphany (lateral compaction), AH Plus + Protaper's proprietory cone, EndoRez + sealer, or Activ GP + sealer). The specimens were mounted on a glucose model and samples were taken for 3 weeks for leakage measurement.

RESULTS

No statistically significant difference was observed between the leakage of all groups at the 3 testing periods (P > .05).

CONCLUSION

The filling materials with the monoblock concept do not seem to be superior to the conventional AH Plus + gutta-percha system regarding microleakage.

Assessment of different dyes used in leakage studies

The goal of this in vitro study was to identify the most suitable dye for endodontic dye leakage studies, which could be a further step towards standardisation. The root canals of 70 extracted, single-rooted human adult teeth were enlarged to apical size 50 using hand instruments. The teeth were divided into seven groups (n = 10 each), and all root canals were completely filled by injection with one of the following dyes: methylene blue 0.5% and 5%, blue ink, black ink, eosin 5%, basic fuchsin 0.5% and drawing ink. Transverse root sections from the coronal, middle and apical part of the roots were examined, and the percentage of the dentine penetrated by dye was evaluated by software-supported light microscopy. In addition, the range of particle size of drawing ink particles was evaluated. There were conspicuous differences in the relative dye penetration into the root dentine and the penetration behaviour in the different root sections (two-way ANOVA, both p < 0.0001). One dye (drawing ink) penetrated less into the root dentine compared with all the others (p <0.0001). The particle size of this agent (0.1-2 microm) corresponds best with the size range of a representative selection of 21 species of pathogenic endodontic bacteria. Compared to the other dyes tested, drawing ink appears to be superior for use in endodontic dye leakage studies. The penetration behaviour into the root dentine of all the other dyes tested might be one factor that limits the applicability of these dyes in dye leakage studies.

Mineral trioxide aggregate in paediatric dentistry

OBJECTIVE

The aim of this study was to present a review of the reported literature on: (i) the physical and chemical properties; and (ii) clinical applications of mineral trioxide aggregate (MTA) in the practice of paediatric dentistry.

METHOD

Electronic literature search of scientific papers from January 1993 to June 2008 was carried out on the MEDLINE, Embase, Entrez Pubmed, and Scopus databases using specific key words. The search yielded 448 papers, out of which 100 were identified as conforming to the applied criteria. These papers formed the basis of the review and the clinical scenarios presented which demonstrate the application of MTA in the practice of paediatric dentistry.

CONCLUSION

Paediatric dentists have successfully employed MTA in a variety of endodontic/restorative applications since the late 1990s. Clinical impressions have generally been favourable and support the findings of laboratory and animal-based investigations. Very few clinical studies have been reported so far in humans, and although these have been positive, the body of research is currently insufficient to enable a meaningful systematic review and meta-analysis.

A quantitative evaluation of sealing ability of 4 obturation techniques by using a glucose leakage test

OBJECTIVE

The aim of this study was to evaluate the sealing ability of 4 different obturation techniques by using a glucose leakage test.

STUDY DESIGN

Eighty extracted single-rooted maxillary incisors were selected for the study. The teeth were decoronated and the root canals prepared using ProFile rotary instruments to an apical dimension of size 40 (0.06 taper). The specimens were then randomly divided into 4 experimental groups (n = 15) and filled with gutta-percha and sealer by using either cold lateral compaction, warm vertical compaction, Thermafil, or the E & Q Plus system. Another 10 teeth each served as the positive and negative controls. A glucose leakage model was used for quantitative evaluation of the coronal-to-apical microleakage at 24 hours, 1, 2, 3, 5, 8, and 12 weeks.

RESULTS

No significant difference in the cumulative amount of leakage was found among the 4 groups at 24 hours and 1 week (Kruskal-Wallis test, P > .05). Lateral compaction showed significantly more leakage than the other 3 techniques at longer intervals (Mann-Whitney U test, P < .008). No significant difference was found between vertical compaction, Thermafil, and E & Q Plus at all observation times.

CONCLUSIONS

Warm vertical compaction, Thermafil, and the E & Q Plus system showed a better sealing result than cold lateral compaction of gutta-percha at extended observation periods. The glucose leakage method used in this study was able to provide a nondestructive, quantitative, and long-term evaluation of the sealing ability of root canal fillings.

Methodologies for assessment of apical and coronal leakage of endodontic filling materials: a critical review

Apical leakage continues to be a topic of great interest, because in spite of the advances in Endodontics, clinical failures still occur. Most failures are probably attributed to the proliferation of bacteria that remain viable after chemical-mechanical preparation and cause periapical tissue irritation. Coronal leakage has aroused researchers' interest over the last few years, since canals may be re-contaminated after loss of coronal sealing or fracture of the remaining tooth. In this review, the various methodologies used for assessing root canal sealing capacity are critically analyzed, as they are not standardized, which makes it difficult to compare the results obtained when different methodologies are used, even though the same substrate is being assessed.

Effects of different root canal obturation techniques on bacterial penetration

OBJECTIVES

The aim of this study was to compare bacterial penetration following obturation with 5 different techniques.

STUDY DESIGN

This study was performed on 120 teeth including negative control (n = 10), positive control (n = 10), and experimental groups (n = 100). One hundred teeth were randomly divided into 5 groups of 20 teeth each and obturated with System B (Sb), Lateral Compaction (Lc), Thermafil (T), Single ProTaper Gutta-percha (P), and laterally compacted ProTaper Gutta-percha (PLc). Enterococcus faecalis was used for determination of the bacterial penetration. Evaluation was carried out for 60 days.

RESULTS

At 30 days, the chi2 test showed that the slowest penetration was observed in Group Sb and Group PLc, which were not significantly different from each other. The fastest penetration in the all experimental groups was observed in Group T and Group P, which were not significantly different from one another. Also, there was no statistically significance difference (P > .05) among all groups at 60 days.

CONCLUSION

It may be concluded that under the conditions of this study System B and laterally compacted ProTaper Gutta-percha prevent bacterial penetration of the root canal at 30 days. Furthermore, there was no difference among obturation techniques at 60 days.

An ex vivo comparison of three different gutta-percha cones when compacted at different temperatures: rheological considerations in relation to the filling of lateral canals

AIM

To compare ex vivo the penetration of three brands of gutta-percha cones, compacted under a constant force and heated to different temperatures, into artificial lateral canals.

METHODOLOGY

Resin blocks with simulated main canals, each having two lateral canals (C at 6.5 and A at 13 mm from the surface of the resin block), were selected. A gutta-percha cone, either Mynol MF, Hygenic MF or GT Tulsa 0.04 was compacted into each main canal for 5 s using a wire rod with a diameter of 0.7 mm soldered to the bottom of a metal cylinder, with a force of 2.7 kg at controlled temperatures of 37, 42, 47, 52, 60 degrees C. The penetration of each brand of gutta-percha into 60 lateral canals (10 at each temperature) was measured using a stereomicroscope. Statistical analysis was performed using the ANOVA, the Scheffè test and the t-test.

RESULTS

None of the three brands of cones entered up to 0.1 mm within either lateral canal until a temperature of 47 degrees C was reached; at that temperature only Mynol cones (P < or = 0.05) penetrated in four of 10 A-level canals (mean 0.13 +/- 0.19 mm) and in all 10 C-level canals (mean 0.43 +/- 0.12 mm). The A-level lateral canals were penetrated at 52 degrees C by Mynol cones (mean 0.76 +/- 0.34 mm) to a significantly greater distance (P < or = 0.05) than Tulsa cones (mean 0.31 +/- 0.12 mm) and Hygenic cones (mean 0.11 +/- 0.08 mm). At 60 degrees C the Mynol cones (mean 1.93 +/- 0.34 mm) penetrated significantly more (P < or = 0.05) than the Tulsa cones (mean 0.86 +/- 0.22 mm) and Hygenic cones (mean 0.67 +/- 0.19 mm). The C-level lateral canals were penetrated at 52 degrees C by Mynol cones (mean 0.91 +/- 0.29 mm) to a significantly greater distance (P < or = 0.05) than Tulsa cones (mean 0.47 +/- 0.16 mm) and Hygenic cones (mean 0.46 +/- 0.15 mm), whilst no significant difference was found at 60 degrees C.

CONCLUSIONS

When heated and compacted, the three gutta-percha cones penetrated the lateral canals to different degrees. They penetrated more than 0.43 mm into the lateral canals only at temperatures higher than 47 degrees C.

Evaluation of canal filling after using two warm vertical gutta-percha compaction techniques in vivo: a preliminary study

AIM

To evaluate the quality of root canal filling when comparing two warm gutta-percha filling techniques in vivo.

METHODOLOGY

Human teeth were randomly divided into two equal groups, with 30 canals each. The root canals were shaped by hand and ProFile 0.04 rotary instruments to size 20-40 at the end-point and then filled with gutta-percha cones and AH-Plus. In group A, a traditional warm vertical compaction technique was performed using the Touch'n Heat, and back-filling with the Obtura II. In group B, a modified warm vertical compaction technique was used: small amounts of gutta-percha were removed, and the remaining most apical 3 mm were compacted with a 1 mm movement; then thermomechanical back-filling was performed. The teeth were extracted, stored in dye, cleared, and the distance between the apex and apical limit of the filling, linear dye penetration, and voids were measured from the buccal, lingual, mesial and distal perspective. The homogeneity of variance and means was verified using Levene's test and t-test. ANOVA and Dunnett post hoc test were used to establish the significance and to analyse the effects through multiple comparisons.

RESULTS

Compared with the specimens of group A, the specimens of group B exhibited less mean linear dye penetration (P < 0.05), smaller void length (P < or = 0.05) and maximal width (P < or = 0.05) when examined in all four views, and a more precise filling when viewed from the buccal aspect (P < 0.05).

CONCLUSIONS

The modified warm vertical compaction technique with apical back-filling produced a more effective and precise three-dimensional filling.

Bacterial penetration after obturation with four different root canal sealers

The aim of this study was to compare bacterial penetration after obturation with lateral compaction technique using four different root canal sealers. This study was performed on 100 teeth including negative control (n = 10), positive control (n = 10), and experimental groups (n = 80). 80 teeth were randomly divided into five groups of 20 teeth each and obturated with AH 26 (A), AH Plus (AP), Sealapex (S), Ketac-Endo (K) root canal sealers. Evaluation was carried out for 60 days. After 30 days of comparing the bacterial penetration values, total penetration was observed in 85% of the Group AP, and group K, 80% of the group S, and 75% of the group A. According to the results of chi(2) test, there was no statistically significant difference observed between any groups (p > 0.05). After 60 days of comparing the bacterial penetration values, total penetration was observed in 100% of the group AP, group K, and group S and 95% of the group A. It may be concluded that under the conditions of this study, there was no difference in the bacterial penetration of the four root canal sealers tested at 30 and 60 days.

Leakage of Bovine Serum Albumin in Root Canals Obturated with Super-EBA and IRM

The aim of this study was to determine the leakage of SuperEBA and intermediate restorative material (IRM) in root canal samples, with or without orthograde filling, by evaluating bovine serum albumin (BSA) microleakage using spectrophotometry. Thirty-five single-rooted teeth were divided into five groups, instrumented, and had apices resected. Root-end cavities in groups I and II were filled with SuperEBA and IRM. The samples from the groups III, IV, and V were filled with gutta-percha and sealer. In groups IV and V, root-end cavities were filled with SuperEBA and IRM. After 60 days, the greatest microleakage of BSA was observed in group II (4.1 +/- 0.0011 ng), followed by group III (3.4 +/- 0.0064 ng), and then group I (2.6 +/- 0.0019 ng). Samples from groups IV and V leaked the least (0.7 +/- 0.0014 ng). Significantly less leakage (p < 0.05) occurred in samples filled with orthograde and root-end fillings than did in samples filled only with an orthograde approach and the samples with IRM root-end fillings.

A study of the rheological properties of endodontic sealers

AIM

To test the hypothesis that there would be no statistically significant difference in viscosity-related measures of endodontic sealers or change in these with strain rate, internal diameter or powder : liquid ratio in a capillary system.

METHODOLOGY

Materials used were Apexit, Tubliseal EWT, Grossman's sealer and Ketac-endo. Viscosity-related measures were tested in a two-plate test, and in a capillary rheometer. The mean values (n = 12) for thickness and diameter of material formed between two glass plates were tested with one-way analysis of variance. Pressure was applied to a capillary rheometer at strain rates 5 and 10 mm min(-1) in tubes of internal diameter 0.6 and 1.2 mm.

RESULTS

Tubliseal EWT had a thinner film thickness than the other sealers (alpha = 0.05). The difference in diameter between Tubliseal EWT and the other sealers was significant apart from Apexit. Increased strain rate gave a significant increase (alpha = 0.05) in the flow of all sealers. Narrower tubes produced increased velocity, which was significant for all sealers, and reduced volumetric flow, which was significant for all sealers except Grossman's 2 : 1 (Wilcoxon signed rank test). Reduction in powder : liquid ratio of Grossman's significantly increased flow in narrow tubes and at higher strain rate (Mann-Whitney test).

CONCLUSION

There was a significant difference between the flow of Tubliseal EWT and the other sealers tested in the two-plate test; capillary flow was affected by sealer, internal diameter, strain rate and powder : liquid ratio. The null hypotheses were rejected.

Apicectomy with the Er:YAG laser or bur, followed by retrograde root filling with zinc oxide/eugenol or sealer 26

OBJECTIVE

This study evaluated the influence of root resection, by means of the use of erbium:YAG laser in sealing two different materials, OZE and Sealer 26, in retrograde obturations.

BACKGROUND DATA

Few studies with sufficient data have been conducted in this area.

METHODS

Forty uniradicular teeth were used. They were biomechanically prepared using the step-back technique and obturated using the lateral condensation technique. The teeth were divided into two groups of 20 teeth, one group using the erbium:YAG laser (350 mJ and 6 Hz) for the resection process and the other using the Zekrya Drill, in high rotation. Then, the retrograde cavities were prepared using a micro counter-angle with a number 2 spherical bur. After preparing the cavities, the teeth were impermeabilized and divided into two subgroups. One subgroup used the retrograde obturation technique with Sealer 26 cement, and the other subgroup used OZE. After completing the retrograde obturation, the teeth were immersed in 2% methylene blue for a 7-day period. Teeth were then removed from the dye, washed, scraped, and sectioned in the vestibule-lingual direction.

RESULTS

The results were analyzed with the aid of a magnifying lens, and scores were attributed based on the magnitude of infiltration. The data were then submitted to statistical analysis.

CONCLUSIONS

No statistical difference was noticed regarding the root resection methods; however, in comparing materials, Sealer 26 was statistically superior to OZE. In the subgroup comparison, a significant difference was noticed in the Laser and Sealer 26 and the Laser and OZE and bur and OZE.

A new quantitative method using glucose for analysis of endodontic leakage

OBJECTIVE

The purpose of this study was to introduce a new method for quantitative testing of endodontic leakage.

STUDY DESIGN

Eighty straight maxillary anterior teeth were divided randomly into 3 experimental groups of 20 samples each and 2 control groups. The experimental groups were prepared using the modified double-flared technique and obturated by lateral compaction of cold gutta-percha with Pulp Canal Sealer EWT, Sealapex, or AH Plus sealer. With the leakage test device, coronal 1 mol/L glucose solution was forced under a hydrostatic pressure of 1.5 kPa toward the apical part of the root. Leakage was measured by the concentration of leaked glucose in apical reservoir at 1, 2, 4, 7, 10, 15, 20, and 30 days with the enzymatic glucose oxidase method.

RESULTS

No significant difference of sealing ability was found among 3 test groups at 1, 2, 4, and 7 days. From the tenth day, Pulp Canal Sealer EWT showed the highest leakage, and the leakage was not significantly different between Sealapex and AH Plus.

CONCLUSIONS

The quantitative method is sensitive, nondestructive, and clinically relevant. Pulp Canal Sealer EWT showed more leakage than Sealapex and AH Plus in most observation time.

Effect of obturation technique on sealer cement thickness and dentinal tubule penetration

AIM

To compare the average sealer cement film thickness and the extent and pattern of sealer penetration into dentinal tubules in association with four obturation techniques in curved root canals.

METHODOLOGY

Mesial canals of 44 extracted mandibular molars were randomly divided among the SimpliFill, continuous wave, Thermafil and 0.04 matched taper (master cones) lateral compaction obturation groups (22 canals per group). AH26 sealer cement was coloured blue-black using Sudan Black B dye. Roots were sectioned 1, 3 and 5 mm from the working length. Specimens were photographed under 25x magnification, mounted as 35 mm slides and projected. Average sealer cement thickness (measured at 10 points around the canal wall), depth of dentinal tubule penetration and frequency of voids were determined at the 1, 3 and 5 mm levels. Data were analysed statistically for effect of obturation technique and level of section on sealer thickness and on the depth and distribution of tubule penetration.

RESULTS

Thermafil demonstrated superior GP adaptation at all levels with a mean overall sealer cement thickness of 2.2 microm, followed by lateral compaction (11.1 microm), continuous wave (12.2 microm) and SimpliFill (47.6 microm). SimpliFill also demonstrated the highest frequency of voids (P < 0.05). Sealer cement penetrated dentinal tubules as far as the outer one-third of dentine, with greater penetration observed buccally or lingually (P < 0.001). Penetration was not significantly affected by obturation technique, but on average was deeper and more frequent at the 3 and 5 mm levels than at the 1 mm level (P < 0.001).

CONCLUSIONS

Sealer thickness was strongly dependent on obturation technique. Assuming that minimal sealer thickness and fewer voids are good measures of long-term sealing ability, Thermafil resulted in the best outcome. Consistent, extensive sealer penetration into dentinal tubules was seen and was unrelated to the obturation technique.

Apical seal of root canals with gutta-percha points with calcium hydroxide

The objective of this research was to determine if gutta-percha points with calcium hydroxide [Ca(OH)2] improve the apical seal after root canal filling and if the master point does it alone. Human single recently extracted teeth were biomechanically prepared and the root canals filled by the lateral condensation technique with ZOE and gutta-percha points, with or without calcium hydroxide. The teeth were placed into a 2% methylene blue solution in a vacuum environment for 24 h after which they were processed for stereomicroscope evaluation. Better results were observed with the teeth filled with gutta-percha points with calcium hydroxide (p=0.01). We conclude that these new points make a better apical seal and that these results can also be obtained with the calcium hydroxide master point associated with regular ones (p=0.05).