Perforation Repair Comparing Two Types of Mineral Trioxide Aggregate

Present status and future directions - Managing perforations

Root perforations are severe complications and are associated with compromised endodontic treatment outcomes, especially when bacterial infection is allowed to establish. Perforations may occur due to pathological processes or treatment consequences. Various dental materials have been proposed over the years for perforation repair with varying degrees of success. The use of bioactive materials, such as mineral trioxide aggregate (MTA) and other calcium-silicate cements, promotes a favourable environment for regeneration and has been used successfully for perforation repair. This is in contrast to materials used previously that often led to unpredictable outcomes. With the increasing range of new bioactive endodontic materials available, the number of potential materials being used for repair of root perforations is growing. Though promising to date, there is little evidence to support the use of most of these new materials. The aim of this narrative review is to provide the background, clinical techniques and outcome of nonsurgical and surgical perforation repair.

Antimicrobial Action, Genotoxicity, and Morphological Analysis of Three Calcium Silicate-Based Cements

This study is aimed at evaluating five mineral oxides (5MO), mineral trioxide aggregate repair high plasticity (MTA HP), and mineral trioxide aggregate (MTA) in relation to the antimicrobial action over Porphyromonas gingivalis, Porphyromonas endodontalis, Parvimonas micra, Fusobacterium nucleatum, and Prevotella intermedia; the genotoxicity over mouse macrophage (RAW 264.7) and osteoblast (Mg-63) cultures; and the morphological analysis using scanning electron microscopy (SEM) analysis (50 k and ×100 k). Sodium hypochlorite (NaOCl), calcium hydroxide, and saline solution were used as control groups in the different analysis. All data were submitted to a normality test and then analyzed with one-way ANOVA, Tukey, and Kruskal-Wallis and Dunn tests, considering α ≤ 0.05 significance level. It was found that over P. gingivalis and P. endodontalis, there was no a significant difference between the calcium silicate-based cements (CSC) and the control group of saline solution, and only 5MO was similar to the NaOCl group. However, over P. micra, all groups were effective and showed a statistically significant difference compared to the saline solution group. Conversely, none of the groups were effective over F. nucleatum and P. intermedia, except of the NaOCl group. There was a significant difference between 5MO and MTA groups in comparison with NaOCl and MTA HP over osteoblasts and macrophages after 24 hours. SEM images showed small irregular particles interspersed with some elongated needle-like particles and small irregular particles with some larger particles as well as elongated particles. It was concluded that 5MO, MTA, and MTA HP have effective antimicrobial action over P. micra. However, only 5MO is effective over P. gingivalis and P. endodontalis. Besides, 5MO and MTA are not genotoxic over mouse macrophage (RAW 264.7) and osteoblast (Mg-63) cultures.

Efficacy of MTA Modified by Nanosilver for the Prevention of Coronal Leakage

Background:

Numerous materials have been introduced as coronal barriers, however, they have shown various degrees of microleakage. Therefore, attempts are undertaken to introduce more reliable materials with the potential to provide a long-term coronal seal.

Introduction:

This in vitro study aimed to assess the efficacy of gray ProRoot Mineral Trioxide Aggregate (MTA) modified by a suspension of silver nanoparticles (AgNPs) as an orifice plug using a bacterial leakage method.

Methods:

40 extracted human teeth were prepared and filled (except for the negative control group) using the lateral compaction technique. The coronal 2 mm of the root filling was removed in the experimental groups. The teeth were randomly divided into two experimental (n = 15) and two control (n = 5) groups. In the experimental group 1 (MTA group) and the experimental group 2 (Ag-MTA group), MTA modified by a suspension of AgNPs was used as an orifice plug. In the negative control group, the entire root surfaces were covered with two layers of nail varnish. In the positive control group, the root canals were filled with a single gutta-percha cone without a sealer and no orifice plug. Bacterial leakage was assessed using a two-chamber system. The teeth were incubated at 37°C and 100% humidity for 120 days, and human saliva was added to the samples every 3 days. Bacterial microleakage was assessed by daily monitoring and observating the turbidity of the Brain Heart Infusion (BHI) broth. The data were analyzed using the log-rank test.

Results:

All positive controls showed contamination after 5 days. None of the negative controls were contaminated during the experiment. The Ag-MTA group demonstrated a significantly better coronal seal than the MTA group (p = 0.031).

Conclusion:

Gray ProRoot MTA modified by AgNPs has the potential for being used as an orifice plug in endodontically treated teeth.

Efficacy of Mineral Trioxide Aggregate and Biodentine as Apical Barriers in Immature Permanent Teeth: A Microbiological Study

Aim

To compare the bacterial leakage of mineral trioxide aggregate (MTA) and biodentine when used as an apical plug in immature permanent teeth.

Materials and methods

It was a randomized double-blind in vitro study. A total of 60 teeth were divided into 2 groups of MTA and biodentine, which were further divided into 2 subgroups (n = 30) each based on the apical plug thickness of 2 and 4 mm. The teeth were cleaned and shaped; root-end resection and canal preparation were done. Mineral trioxide aggregate and biodentine were mixed and filled as apical plugs of 2 or 4 mm thickness. Enterococcus faecalis was used to assess the bacterial leakage of the filled samples.

Statistical analysis

The comparison between the two groups was done by Chi-square test for categorical data. All p values <0.05 were considered as statistically significant.

Results

A 4 mm apical plug of biodentine showed the least amount of bacterial leakage followed by 2 mm MTA and 4 mm MTA. A 2 mm apical plug of biodentine showed the maximum bacterial leakage. But this was not statistically significant over a period of 3 months. There was a statistically significant difference (p value = 0.042) among the total number of samples that leaked in the 2 and 4 mm biodentine group.

Conclusion

Mineral trioxide aggregate and biodentine had a similar apical sealing ability. The apical sealing ability of biodentine at 4 mm thickness was greater than 2 mm thickness.

Clinical significance

The apical leakage of the materials used in apexification is one of the main causes of endodontic failures in immature necrotic teeth. Materials like MTA and biodentine have overcome various drawbacks of calcium hydroxide as apexification material. The thickness of the apical plug plays an important role in preventing any microorganism from entering the periapical area, hence maintaining an adequate seal.

How to cite this article

Abbas A, Kethineni B, Puppala R, et al. Efficacy of MTA and Biodentine as Apical Barriers in Immature Permanent Teeth: A Microbiological Study. Int J Clin Pediatr Dent 2020;13(6):656-662.

Effect of Irrigants on the Push-Out Bond Strength of Two Bioceramic Root Repair Materials

The purpose of this study was to compare different irrigants’ effect on two EndoSequence root repair materials’ push-out bond strength. Sixty root slices were filled either with EndoSequence premixed fast-set putty or regular-set paste, and then immersed either in sodium hypochlorite, chlorhexidine gluconate, or saline (as control) for 30 min, after which the slices were subjected to the push-out test. The surface structures were evaluated with Scanning Electron Microscopy and Fourier Transform Infrared. Fast-set putty exhibited greater displacement resistance when immersed in saline and subjected to adhesive failure mode, while regular-set paste showed greater resistance when immersed in chlorhexidine and subjected to cohesive failure mode. Infrared analysis showed changes in organic filler, and carbonate and phosphate bands after using irrigants. The lowest carbonate/phosphate ratio was found for chlorhexidine in both materials. Therefore, sodium hypochlorite reduced EndoSequence root repair materials’ displacement resistance markedly.

Push-out bond strength of calcium-silicate cements following Er:YAG and diode laser irradiation of root dentin

This study aimed to compare the effects of diode and Er:YAG laser irradiation of root dentin on push-out bond strength of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cements. An in vitro experimental study was conducted on 90 dentin discs, cut out of freshly extracted human teeth. The discs were instrumented to obtain 1.3-mm lumen diameter. Then, they were randomly divided into six groups (n = 15). Groups 1 and 4 subjected to diode laser (Wiser, Doctor Smile, Italy) (980 nm, 1 W, continuous mode) for 10 s and filled with MTA and CEM cements. Groups 2 and 5 subjected to Er:YAG laser (Deka, Italy) (2940 nm, 1 W, 10 Hz, 230 μs) for 10 s and filled with MTA and CEM cements. Groups 3 and 6 (control groups) were filled with MTA and CEM cements without laser irradiation. After 7 days, push-out bond strength test was performed using a universal testing machine in order to evaluate the adhesion of the biomaterials to dentin. The samples were evaluated under a light microscope at × 40 magnification to determine the mode of fracture. Data were analyzed using two-way ANOVA. The highest push-out bond strength (8.76 ± 3.62 MPa) was noted in group 1 (diode/MTA), which was significantly higher than the other groups (P < 0.001). The lowest bond strength (2.61 ± 0.81) was noted in group 6 (control/CEM). Diode laser significantly increased the bond strength of both cements (P < 0.05), but Er:YAG laser irradiation only increased the bond strength of CEM and had no significant effect on MTA (P = 0.603). The bond strength of MTA control group was higher than that of CEM control group (P = 0.001). Push-out bond strength of endodontic cements can be affected by dentin conditioning with diode 980 nm and Er:YAG laser. Nine hundred eighty-nanometer diode laser irradiation is recommended to increase the bond strength of endodontic cements particularly the CEM cement to dentin.

Effects of chelating agent and acids on Biodentine

BACKGROUND

To evaluate the effect of distilled water, ethylenediaminetetraacetic acid (EDTA), phosphoric acid and maleic acid on Biodentine regarding surface topography, microhardness and push-out bond strength (POBS).

METHODS

Fifty-two cylindrical shaped Biodentine specimens were divided into groups: control (distilled water); EDTA (17% EDTA); PA (37% phosphoric acid); and MA (7% maleic acid). Surfaces were evaluated by topographic analysis and Vickers microhardness test. Topographic changes were evaluated qualitatively and microhardness was statistically analyzed by Kruskal-Wallis test. Forty mandibular molars were used to simulate clinical conditions. The crowns were removed and a perforation was created at the furcal floor. The Biodentine was packed into the root perforations and the roots were divided into four groups (DW, EDTA, PA, MA). Samples were stored and subjected to interfacial analysis. POBS data were analyzed by Kruskal-Wallis and Dunn tests.

RESULTS

Ethylenediaminetetraacetic acid, MA and PA changed the morphology of the Biodentine surface. PA showed microhardness similar to distilled water (P > 0.05), while MA and EDTA demonstrated reduced values when compared with PA (P < 0.05). PA improved the POBS of Biodentine in comparison with the control.

CONCLUSIONS

Changes in the topography, microhardness and POBS of Biodentine are associated with irrigant agent used.

In Vitro Sealing Properties of Calcium-Enriched Mixture and Mineral Trioxide Aggregate Orifice Barriers during Intra-Coronal Bleaching

Introduction:

This study aimed at evaluating the sealing properties of calcium-enriched mixture (CEM) compared to mineral trioxide aggregate (MTA) as a cervical barriers in intra-coronal bleaching.

Methods and Materials:

In this in vitro study, endodontic treatment was performed on 60 extracted human incisors and canines without canal calcification, caries, restorations, resorption or cracks. The teeth were then randomly divided into two experimental groups and two control groups (n=15). Then, CEM cement and MTA were applied as 3-mm intra-orifice barriers in the test groups; a mixture of sodium perborate and 30% hydrogen peroxide bleaching agents were placed within the pulp chamber for one week. Dye penetration method was used to evaluate the sealing ability of agents. Statistical analysis was performed using SPSS software. The Kendall coefficient was used to evaluate inter-observer agreement. The chi-squared test was used for statistical analysis.

Results:

The results showed that the penetration rates of CEM and MTA were the same as positive control group, with no significant differences (P=0.673 and P=0.408, respectively). However, there was a significant difference between the negative control group and CEM and MTA groups (P=0.001 for both groups). In addition, the sealing ability of MTA and CEM cement were not significantly different (P=0.682).

Conclusion:

During intra-coronal bleaching procedures CEM cement can be used as a cervical barrier with sealing properties comparable to that of MTA.

Influence of powder composition and morphology on penetration of Gray and White ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules

This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (μm), width (μm), perimeter (μm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. (J Oral Sci 56, 287-293, 2014).

The effects of Various Endodontic Irrigants on the Push-out Bond Strength of Calcium-Enriched Mixture Cement and Mineral Trioxide Aggregate

Introduction:

The aim of this in vitro study was to evaluate the effect of various irrigants on the push-out bond strength of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA).

Methods and Materials:

A total of 140 dentin disks with a thickness of 1.5±0.2 mm and lumen size of 1.3 mm, were randomly divided into 12 groups (n=10) and 4 control groups (n=5). The lumen of disks in groups 1, 2, 3, 7, 8, 9 were filled with CEM and groups 4, 5, 6, 10, 11, 12 were filled with MTA. Control groups were filled with CEM and MTA. Specimens were incubated at 37^°C for one day in groups 1 to 6 and seven days in groups 7 to 12. After incubation the samples were divided into three subgroups (n=10) that were either immersed for 30 min in 5.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) or saline solution. The push-out bond strength values were measured by using a universal testing machine. The nature of the failures were determined by light microscope. Data was analyzed using the three-way ANOVA to evaluate the effect of material type, different irrigants and time intervals. Post hoc Tukey’s test was used for two-by-two comparison of the groups.

Results:

CEM cement significantly showed a higher push-out bond strength in comparison with MTA (P=0.001). The elapse of time significantly increased the bond strength (P=0.001). There was no significant difference between the irrigants used in this study (P=0.441). Bond failure was predominantly of mixed type in MTA and of cohesive type in CEM samples.

Conclusion:

Based on this study, endodontic irrigants did not influence the push-out bond strength of MTA and CEM cement.

Sealing Ability of MTA Used in Perforation Repair of Permanent Teeth; Literature Review

There were several materials used to seal different types of perforation defects. MTA is one of these restorative materials that is considered the most effective, biocompatible, non-toxic, and non-irritant; promote bone healing and cementum regeneration. The objective of this article was to review and summarize the sealing ability of MTA compared with the other materials used for sealing different types of root perforations of permanent teeth. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2005 to 2015 searching for articles related to sealing ability of MTA. This study found that factors affecting prognosis are the size, site of the perforation and time elapsed as well as the repair material. MTA is an important filling material to be used for sealing different types of perforations when perforated sites sealed immediately with MTA.

Comparison of Tooth Discoloration Induced by Calcium-Enriched Mixture and Mineral Trioxide Aggregate

Introduction:

The aim of this in vitro study was to evaluate the tooth discoloration induced by calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA).

Methods and Materials:

Forty five endodontically treated human maxillary central incisors were selected and divided into three groups (n=15) after removing the coronal 3 mm of the obturating materials. In the MTA group, white MTA plug was placed in pulp chamber and coronal zone of the root canal. In CEM cement group, CEM plug was placed in the tooth in the same manner. In both groups, a wet cotton pellet was placed in the access cavity and the teeth were temporarily sealed. After 24 h the teeth were restored with resin composite. In the negative control group the teeth were also restored with resin composite. The color change in the cervical third of teeth was measured with a colorimeter and was repeated 3 times for each specimen. The teeth were kept in artificial saliva for 6 months. After this period, the color change was measured again. Data were collected by Commission International de I'Eclairage's L*a*b color values, and corresponding ΔE values were calculated. The results were analyzed using the one-way ANOVA and post-hoc Tukey’s test with the significance level defined as 0.05.

Results:

There was no significant differences between CEM group and control group in mean discoloration. The mean tooth discoloration in MTA group was significantly greater than CEM and control groups (P<0.05).

Conclusion:

According to the result of the present study CEM cement did not induce tooth discoloration after six months. Therefore it can be used in vital pulp therapy of esthetically sensitive teeth.

Bacterial Leakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture and Biodentine as Furcation Perforation Repair Materials in Primary Molars

Introduction:

Adequate seal of iatrogenically perforated area within the root canal system can improve the long term treatment prognosis. This in vitro study evaluated the sealing ability of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine in repair of furcation perforation in primary molars.

Methods and Materials:

A total of 61 freshly extracted primary mandibular second molars were randomly divided into three groups (n=17) and 10 teeth were put in negative (without perforation, n=5) and positive (perforated without repair, n=5) control groups. Turbidity was used as the criteria of bacterial leakage, when detected in the model of dual-chamber leakage. Data were analyzed using the Chi-Square and Kaplan-Meier survival analysis in SPSS software. The level of significance was set at 0.05.

Results:

All positive samples showed turbidity, whereas none of the negative samples allowed bacterial leakage. There was no significant difference between the number of turbidity samples in repaired teeth with all test materials (P=0.13). No significant difference was also detected in the mean survival time (P>0.05).

Conclusion:

CEM cement and Biodentine showed promising results as perforation repair materials and can be recommended as suitable alternatives of MTA for repair of furcation perforation of primary molars.

The setting mechanism of mineral trioxide aggregate

Mineral trioxide aggregate (MTA) is a powder containing calcium silicate composed of hydrophilic particles which harden at the presence of moisture. MTA was initially introduced as a root end filling material. Due its practical advantages that include superior biocompatility, effective sealing capability, and the ability to improve regeneration of the pulp and peripheral root tissues, it is used in different clinical applications such as pulp capping, apexification, pulpotomy and perforation. Despite being a promising material in endodontic treatment, MTA is not commonly used. Long setting time is the main clinical disadvantage of MTA. The aim of this review is to provide an overview of the current literature concerning the setting mechanism of MTA, accelerators and devices used to evaluate various steps of the hardening process.

Comparing gray and white mineral trioxide aggregate as a repair material for furcation perforation: an in vitro dye extraction study

INTRODUCTION

Furcation perforation can have a negative impact on the prognosis of the affected tooth by compromising the attached apparatus. Hence these perforations require immediate repair. A variety of materials have been suggested for repair, of that MTA is the most promising material. The purpose of this study was to compare the ability of Gray and White MTA to seal furcation perforations using a dye extraction method under spectrophotometer.

MATERIALS AND METHODS

A total of 60 permanent mandibular molars were randomly divided into four experimental groups of 15 samples each as follows: Group A: Perforation repaired with White MTA. Group B: Perforation repaired with Gray MTA. Group C: Perforation left unsealed (positive). Group D: without perforation (negative). Dye extraction was performed using full concentration nitric acid. Dye absorbance was measured at 550 nm using spectrophotometer. The data analyzed using one-way-Anova Ratio and Unpaired t-test showing statistically significance difference among the groups.

RESULT

It was seen that Group D samples without perforation showed least absorbance followed by Group A (perforation repaired with White MTA) and Group B (perforation repaired with Gray MTA). Group C (perforation left unsealed) showed highest absorbance.

CONCLUSION

The White and Gray Mineral Trioxide Aggregate performed similarly as a furcation perforation repair material. There was no significant difference between the Gray MTA and White MTA.

Pulp revascularization in immature permanent tooth with apical periodontitis using mineral trioxide aggregate

Mineral trioxide aggregate (MTA) is a material that has been used worldwide in several clinical applications, such as apical barriers in teeth with immature apices, repair of root perforations, root-end filling, pulp capping, and pulpotomy. The purpose of this case report was to describe successful revascularization treatment of an immature mandibular right second premolar with apical periodontitis in a 9-year-old female patient. After preparing an access cavity without anesthesia, the tooth was isolated using a rubber dam and accessed. The canal was gently debrided using 5% sodium hypochlorite (NaOCl) and 3% hydrogen peroxide irrigant. And then MTA was packed into the canal. X-ray photographic examination showed the dentin bridge 5 months after the revascularization procedure. Thickening of the canal wall and complete apical closure were confirmed 10 months after the treatment. In this case, MTA showed clinical and radiographic success at revascularization treatment in immature permanent tooth. The successful outcome of this case suggests that MTA is reliable and effective for endodontic treatment in the pediatric dentistry.

Biologic response of local hemostatic agents used in endodontic microsurgery

Appropriate use of local hemostatic agent is one of the important factors on the prognosis of endodontic microsurgery. However, most investigations to date focus on the hemostatic efficacy of the agents, whereas their biologic characteristics have not received enough attention. The purpose of this paper was to review the biologic response of local hemostatic agents, and to provide clinical guidelines on their use during endodontic microsurgery. Electronic database (PUBMED) was screened to search related studies from 1980 to 2013, and 8 clinical studies and 18 animal studies were identified. Among the materials used in these studies, most widely-investigated and used materials, epinephrine, ferric sulfate (FS) and calcium sulfate (CS), were thoroughly discussed. Influence of these materials on local tissue and systemic condition, such as inflammatory and foreign body reaction, local ischemia, dyspigmentation, delayed or enhanced bone and soft tissue healing, and potential cardiovascular complications were assessed. Additionally, biological property of their carrier materials, cotton pellet and absorbable collagen, were also discussed. Clinicians should be aware of the biologic properties of local hemostatic agents and their carrier materials, and should pay attention to the potential complications when using them in endodontic microsurgery.

Washout resistance of fast-setting pozzolan cement under various root canal irrigants

Objectives

Fast-setting pozzolan cement (Endocem, Maruchi) was recently developed. The aim of this study was to investigate the effects of various root canal irrigants on the washout of Endocem in comparison to the previously marketed mineral trioxide aggregate (ProRoot; Dentsply) in a furcal perforation model.

Materials and Methods

ProRoot and Endocem were placed into acrylic molds on moist Oasis. Each mold was then immediately exposed to either physiologic saline, 2.5% sodium hypochlorite (NaOCl), or 2% chlorhexidine (CHX) under gentle shaking for five minutes. Washout testing was performed by scoring scanning electron microscope (SEM) images.

Results

Endocem exhibited higher washout resistance compared to ProRoot, especially in the NaOCl group.

Conclusions

These results suggest that Endocem can be considered a useful repair material for furcal perforation, especially in a single-visit scenario.

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.

Management of pulpal floor perforation and grade II Furcation involvement using mineral trioxide aggregate and platelet rich fibrin: A clinical report

To report the management of an iatrogenic perforation of pulpal floor in the furcation of mandibular first molar, using Mineral Trioxide Aggregate (MTA) and platelet rich fibrin (PRF). Unpredictable endodontic root/pulp chamber floor perforations resulting in unacceptable high rate of clinical failure has now been a lesser threat with the advent of new technologies and biocompatible materials that utilize the applications of basic research along with tissue engineering concept in clinical practice. Present case report illustrates the use of MTA and platelet rich fibrin (PRF) for the repair of the perforation defect and regeneration of the lost periodontium in furcation area. Although, histologic events and reaction of MTA with PRF is not studied so far, however, the autologous and biocompatible nature of the components used for present treatment modalities seems to be beneficial for the long term clinical results obtained in our case.

Radiographic evaluation of furcal perforations sealed with different materials in dogs' teeth

OBJECTIVE

The objective of this work was to evaluate, using radiographic images, the behavior of four materials used to repair root perforations in dogs' teeth.

MATERIAL AND METHODS

Second and third premolars of 6 dogs were used. The 48 teeth were randomly divided into 4 groups (n=12) and the perforations were sealed with one of the following materials: MTA, AH Plus, Vitremer and gutta-percha. Dogs were submitted to general anesthesia, teeth were radiographed and pulp was accessed. Perforations were done, at the maximum curve of the pulp floor, sealed and the accessed coronal cavity was filled with glass ionomer cement (Vidrion R). After 90 days, the dogs were sacrificed and the last x-ray image was taken. Images were analyzed for the presence/absence of periodontal lesions at the perforation region. Data were analyzed statistically by chi-square test at 5% significance level.

RESULTS

There were no statistically significant differences (p>0.05) among AH Plus, Vitremer and gutta-percha groups. MTA produced the smallest number of periodontal lesions (p<0.05).

CONCLUSIONS

It may be concluded that none of the tested materials was able to preserve the integrity of the periodontal tissues in the furcation region, and the use of MTA resulted in the least formation of adjacent periodontal bone lesions revealed by the radiographic comparisons.

Strategies to manage permanent non-vital teeth with open apices: a clinical update

If dental pulp injury occurs prior to complete root formation and apical closure, normal root development is halted. This condition produces several complications. Firstly, the apical diameter of the canal is often larger than the coronal diameter, so debridement is difficult. Secondly, the lack of an apical stop makes the obturation in all dimensions virtually impossible. And finally, the thin walls of the root canal are prone to fracture, so that surgical treatment is generally not a viable option. There are a number protocols to manage non-vital open-apex teeth such as apexification, apical barrier technique (one-visit apexification), orthograde root filling using MTA, triple antibiotic paste, and tissue engineering concept. The aim of this paper is to review these treatment protocols.

Endodontic essay

"It has been said that Mineral Trioxide Aggregate is driving an endodontic revolution. Discuss this statement considering the biological and clinical attributes of this innovative material."

Effects of root canal irrigants on the push-out strength and hydration behavior of accelerated mineral trioxide aggregate in its early setting phase

INTRODUCTION

The purpose of this study was to evaluate the effects of endodontic irrigants on the push-out strength and hydration behavior of accelerated mineral trioxide aggregate (MTA) in its early setting phase.

METHODS

In an in vitro perforation model, MTA with or without 10% CaCl(2) was condensed and allowed to initial set for 10 minutes. The samples were divided into four groups (n = 10) to be immersed into either 3.5% sodium hypochlorite (NaOCl) or 2% chlorhexidine gluconate (CHX) for 30 minutes and then allowed to set for 48 hours. In the control group, a wet cotton pellet was placed over MTA. The maximum force applied to the set MTA mixture before dislodgement was recorded. Irrigant-treated surfaces were examined using a scanning electron microscope (SEM). Chemical elements of these surfaces were also analyzed by energy dispersive x-ray spectroscope (EDS).

RESULTS

The push-out strength of group A1 (NaOCl-treated accelerated MTA) was the highest of all groups. When compared with nonaccelerated MTA, CaCl(2)-accelerated MTA showed significantly higher push-out strength (p < 0.05). NaOCl-treated groups showed significantly higher push-out strength than CHX-treated groups (p < 0.05). Scanning electron microscopic examination and EDS analysis showed that the formation of calcium hydroxide crystals on accelerated MTA exposed to NaOCl was increased compared with those of the control group.

CONCLUSION

These findings imply that the use of accelerated MTA under the NaOCl irrigation was effective in perforation repair without altering its hydration behavior even in the early setting phase.

The antimicrobial activity of gray-colored mineral trioxide aggregate (GMTA) and white-colored MTA (WMTA) under aerobic and anaerobic conditions

OBJECTIVE

The objective of this study was to test the hypothesis that the antimicrobial activity of gray-colored MTA (GMTA) and white-colored MTA (WMTA) is related to the induction of reactive oxygen species (ROS).

STUDY DESIGN

In vitro antimicrobial activity of MTA was carried out using E. coli mutant (AB2463-RecA13), triple mutant (BW535), and wild type (AB1157). The diffusion method on Müller-Hinton agar (MHA) was used. A base layer was made using MHA agar and 4 wells were made by removing agar at equidistant points. MTA was placed into the wells immediately after manipulation. The plates were incubated at 37 degrees C for 48 hours under aerobic and anaerobic conditions. Afterward the zones of inhibition were measured. Also the damage caused to the plasmid DNA in the presence of the cement was evaluated through 0.8% agarose gel electrophoresis.

RESULTS

It was possible to observe a zone of inhibition under aerobic conditions promoted by both cements on both of the mutant E. coli but not in the wild-type E. coli. On the other hand, both cements were not able to induce any bacterial inhibition under anaerobic conditions, suggesting that the inhibitory action is a result of ROS production. Both cements promoted damage in the DNA plasmid when compared with distilled water (control).

CONCLUSION

We concluded that MTA under aerobic conditions provoked antimicrobial activity by induction of ROS. Furthermore, the antimicrobial activity occurred by damage caused directly to the bacterial DNA.

Comparative evaluation of antimicrobial activity of three cements: new endodontic cement (NEC), mineral trioxide aggregate (MTA) and Portland

Using the agar diffusion method, we conducted an in vitro study to evaluate the antimicrobial activity of mineral trioxide aggregate (MTA), new endodontic cement (NEC) and Portland cement at different concentrations against five different microorganisms. A base layer was made using Muller-Hinton agar for Escherichia coli (ATCC 10538) and Candida (ATCC 10231). For Actinomyces viscosus (ATCC 15987), Enterococcus faecalis (ATCC 10541) and Streptococcus mutans (ATCC 25175) blood agar medium was used. Wells were formed by removing the agar, and the materials were placed in the well immediately after manipulation. The plates were kept at room temperature for 2 h for prediffusion, and then incubated at 37 degrees C for 72 h. The inhibition zones were then measured. The data were analyzed using ANOVA and the Tukey test to compare the differences among the three cements at different concentrations. The positive controls showed bacterial growth, while the negative controls showed no bacterial growth. All materials showed antimicrobial activity against the tested strains except for Enterococcus faecalis. NEC created larger inhibition zones than MTA and Portland cement. This difference was significant for Portland cement (P < 0.05), but not for MTA (P > 0.05). Among the examined microorganisms, the largest inhibition zone was observed for Actinomyces group (P < 0.05). The antimicrobial activity of the materials increased with time and concentration (P < 0.05). It was concluded that NEC is a potent inhibitor of microorganism growth.

Shear bond strength of conventional glass ionomer cements bound to mineral trioxide aggregate

INTRODUCTION

This study measured the shear bond strength of conventional glass ionomer cements (GICs; Ketac Molar Easymix and Fuji IX) bonded to white mineral trioxide aggregate (WMTA) that had been allowed to set for 2 different time intervals.

METHODS

Forty-eight WMTA specimens were prepared; half were stored for 45 minutes, and the remaining 24 specimens were stored for 72 hours at 37 degrees C and 100% humidity. Then each group was divided into 2 subgroups of 12 specimens, and each GIC was layered on each of the 2 WMTA preparations. The GIC-WMTA shear bond strengths were measured and were compared by using one-way analysis of variance.

RESULTS

The shear bond strengths with the 45-minute and 72-hour WMTAs were 8.85 and 9.16 MPa, respectively, for Ketac Molar Easymix and 9.34 and 9.96 MPa, respectively, for Fuji IX. The GIC-WMTA bond strength was not different between GIC applications to WMTA that had set for 45 minutes versus 72 hours (P >.05).

CONCLUSIONS

GICs might be used over MTA after the MTA has set for 45 minutes to allow single-visit procedures.

MTA preparations from different origins may vary in their antimicrobial activity

OBJECTIVE

The antimicrobial effects of 4 mineral trioxide aggregate (MTA) preparations, 2 white-colored (WMTA-1, WMTA-2) and 2 gray-colored (GMTA-1, GMTA-2), against C. albicans and E. faecalis were assessed in vitro.

METHODOLOGY

Minimal inhibitory concentration (MIC) for each preparation was determined using the tube dilution test and Sabouraud agar media for C. albicans and brain heart infusion media for E. faecalis. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 24-, 48-, and 72-hour time periods. Samples of 0.1 mL from each of the experimental and control tubes were subcultured on agar or brain heart infusion plates to confirm visible signs of bacterial or fungal growth.

RESULTS

MIC of MTA against the 2 microorganisms tested varied among the 4 preparations tested. WMTA-1 and WMTA-2 inhibited C. albicans growth at concentrations of 3.125 mg/10 mL and 25 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). WMTA-1 and WMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 50 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). GMTA-1 and GMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 3.125 mg/10 mL, respectively, and statistically significant differences were found between GMTA-1 and GMTA-2 (P < .001). Both GMTA-1 and GMTA-2 inhibited C. albicans growth at a concentration of 3.125 mg/10 mL and no statistical differences were found between the preparations. Subculture of the broth tubes in agar or brain heart infusion plates confirmed the turbidity test result.

CONCLUSION

The origin of MTA as well as the type of preparation may affect its antimicrobial characteristics. Clinicians should be aware of variations that may exist among such MTA preparations.

Bioactive materials in endodontics

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements. Special emphasis is made on promising new biomaterials, such as injectable bone substitute and injectable calcium phosphate cements. These materials, which combine biocompatibility, bioactivity and rheological properties, could be good alternatives in endodontics as root canal fillers. They could also be used as drug-delivery vehicles (e.g., for antibiotics and growth factors) or as scaffolds in pulp tissue engineering.

Comparison of mineral trioxide aggregate and formocresol as pulp medicaments for pulpotomies in primary molars

PURPOSE

The aim of this study was to compare the effect of white mineral trioxide aggregate (MTA) to that of formocresol (FC) as pulp dressing agents in pulpotomised primary molars.

METHODS

In this clinical trial study, 60 lower second primary molars of 46 children were treated by a conventional pulpotomy technique. The teeth were randomly assigned to the MTA (experimental) and FC (control) groups by random numbered table. Following removal of the coronal pulp and haemostasis, the pulp stumps were covered with an MTA paste in the experimental group. In the control group, FC was placed with a cotton pellet over the pulp stumps. The teeth of both groups were restored with stainless steel crowns. Children arrived for clinical and radiographic follow-up evaluation after 6, 12 and 24 months.

RESULTS

The treated teeth in FC group (n = 18) were clinically and radiographically successful after 24 months. The radiographic follow-up evaluation revealed one failure (furcation involvement) in 18 molars treated with MTA after 24 months. The treated teeth in MTA group were clinically successful 24 months postoperatively. Pulp canal obliteration was observed in one of the teeth treated with MTA and four of the teeth treated with FC.

CONCLUSION

MTA could be used as a safe medicament for pulpotomy in cariously exposed primary molars and could be a substitute for FC.

In vitro evaluation of the sealing ability of MTA used for the repair of furcation perforations with and without the use of an internal matrix

OBJECTIVE

To evaluate the effect of matrix on mineral trioxide aggregate (MTA) when used to repair furcal perforations.

STUDY DESIGN

Forty-five human molars with furcal perforations were randomly divided into 3 groups and repaired with MTA either alone or over a barrier (calcium sulfate or Collaplug). Eight teeth without perforations provided negative control samples. After assessing repair quality, 1 mol/L glucose solution was used as the tracer to detect the leakage. The concentration of leaked glucose was measured after 1, 2, 4, 7, 15, and 20 days using a glucose oxidase method.

RESULTS

No significant difference in either leakage or overfilling was found between the groups with Collaplug and MTA alone (P > .05). Although no overfilling was detected in the group with calcium sulfate, that group had the most leakage (P < .05).

CONCLUSIONS

Neither of the 2 internal matrices improved the sealing ability and reduced the incidence of overfilling simultaneously.