In vitro evaluation of apical sealing in root apex treated with demineralization agents and retrofiled with mineral trioxide aggregate through marginal dye leakage

Sealing Ability and Adaptability of Nano Mineral Trioxide Aggregate as a Root-End Filling Material

Aim: Comparison between Nano MTA & MTA as a root-end filling materials regarding adaptability and sealing ability. Materials and Methods: Forty extracted human maxillary incisors with straight roots were used. After root canals preparation and obturation, the apical 3 mm of each root was resected perpendicular to the long axis of the tooth. Root end cavities were prepared to a depth of 3mm parallel to the long axis of the tooth. The teeth were randomly divided into two main equal groups of 20 samples each according to the root-end filling material used either MTA or Nano MTA. Ten samples from each group were sectioned longitudinally into two equal halves to measure the sealing ability and another ten samples from each group were sectioned transversally to obtain 1 mm thick section to measure the adaptability of both materials. All samples were photographed under the SEM at three different magnifications (×1000). The gap thickness between the root end filling material and the retro cavity dentine walls were measured at seven selected points at the material-dentine interface in micrometers (µm). Results: Nano MTA and MTA showed no statistically significant difference in the gap thickness between dentin-material interface in both longitudinal and transverse sections. Regarding the sealing ability, the mean value in MTA was (3.27±0.77), while the mean in Nano-MTA was (3.15±0.71). Regarding the adaptability, the mean value in MTA was (2.46±0.60), while the mean in Nano-MTA was (2.05±0.712). Both materials showed good sealing ability and good adaptation to the dentinal wall. Conclusion: Nano MTA revealed good sealing ability and adaptability comparable to MTA when used as a retrograde filling material.

Comparative evaluation of the apical leakage of different bioceramic retrofilling materials with and without smear layer: A stereomicroscopic study

Objective

Present in-vitro study aimed to evaluate the apical leakage of different bioceramic retrofilling materials with and without smear layer.

Materials and Methods

: Sixty human single-rooted teeth were decoronated at a standardized root length of 13 mm, chemo-mechanically prepared and obturated. After obturation, root-end resection was done and root-end cavities were prepared using ultrasonic tips. The specimens with prepared retro cavities were randomly assigned into 2 groups (n = 30) based on the smear layer removal protocol used. Each group was further subdivided into 3 subgroups (n = 10) based on the bioceramic retrofilling material MTA (Mineral Trioxide Aggregate; Proroot Dentsply/Tulsa), CEM (Calcium-Enriched Mixture; Bionique Dent, Tehran) and ERRM (EndoSequence® Root Repair Material; Brasseler USA, Savannah, GA). The extension of dye (2% Rhodamine B) penetration was measured in millimetre using a stereomicroscope at 10× zoom. Results were statistically analysed using one-way ANOVA (analysis of variance) test and unpaired Student's t test.

Results

In the presence of smear layer, MTA demonstrated maximum mean apical leakage value (1.70 ± 0.30), followed by CEM (1.40 ± 0.37) and ERRM (1.40 ± 0.23), which was statistically not significant. Without the smear layer, ERRM demonstrated the least mean apical leakage value, which was statistically significant as compared with CEM (P <.05) and MTA (P <.01).

Conclusion(s)

: All bioceramic retrofilling materials demonstrated apical leakage irrespective of the presence or absence of the smear layer. The presence of a smear layer is beneficial for the sealing ability of MTA and CEM, whereas, the absence of the smear layer is advocated while using ERRM.

An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus, Pro Root MTA, BIODENTINE & Glass Ionomer Cement Using Dye Penetration Method

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each sample was resected apically by removing 3 mm of the apex and filled with different materials. Samples were kept in buffering solution at 37 °C until the recommended evaluation periods. The specimens were then suspended in 1% methylene blue for 24 h, prior to the analysis. The teeth were then sectioned, and dye penetration was examined, photographed, and evaluated under a stereomicroscope. Results: Vertical dye penetration showed significant differences across different groups. The minimum dye penetration was seen in Neo MTA plus followed by BIODENTINE, Pro Root MTA and maximum in GIC. There was no significant difference in dye penetration between Neo MTA plus and BIODENTINE both at fifteen days and one-month intervals. Conclusion: The present study suggests Neo MTA plus and BIODENTINE should be the preferred material for root end filling.

Sealability of Different Root Canal Nanosealers: Nano Calcium Hydroxide and Nano Bioactive Glass

Background:

The success of the endodontic treatment is largely dependent on the sealing achieved by root canal obturation. The application of sealer fills imperfections and increases adaptation of the root filling to the canal walls.

Aim:

To evaluate the sealability of experimental nanosealers (nano calcium hydroxide and nano bioactive glass) and to compare it with the commercial zinc oxide eugenol sealer using a dye penetration method.

Materials and Methods:

Sixty single-rooted mandibular premolars were selected. The tooth crowns were removed so as to obtain standardized 15-mm-long root specimens. The root canal was instrumented with Protaper Ni-Ti rotary file and the final file size was up to # F4/.06 (in vitro study). They were then randomly allocated into 3 groups of 20 specimens each (n=20) according to the sealer used for obturation, and all samples were filled with single cone gutta-percha (#40/06) and one of the tested sealers. All teeth were coated with nail polish and then suspended in 2% methylene blue dye for 7 days. Stereo-microscope (x10) was used to evaluate the sealability of newly introduced nanosealers. The data were statistically analyzed by ANOVA test followed by post hoc analysis (P < 0.05).

Results:

Significant improvement shown by the presented study suggests that nano calcium hydroxide sealer showed significantly less dye leakage than nano bioactive glass sealer and zinc oxide eugenol sealer.

Conclusion:

The results of this study showed that the synthesized nano-powder sealers are suitable for use in root canal therapy to prevent leakage.

The root canal can be sealed better by using smaller nano-powder particle sizes. In addition, the two groups exhibited significant differences in leakage in comparison with commonly used ZOE sealer.

Sealing ability of Biodentine versus ProRoot mineral trioxide aggregate as root-end filling materials

Aim

This study evaluated the sealing ability of ProRoot MTA and Biodentine as root-end filling materials.

Method

In total, twenty (N = 20) extracted human maxillary central incisor teeth were decontaminated, cleaned and decoronated. Instrumentation was performed according to the step back technique using #50 Flex-o-file. Then the canals were flared to #70 Flex-o-file. Obturation was performed with conventional gutta percha and a resinous sealer (AH26) using the lateral condensation technique. Resection of 3 mm of apical end of each root was achieved perpendicular to the long axis of the root. Root-end cavity was prepared in each sample ultrasonically then filled with tested materials (N = 10). Fluid filtration method was used to assess the sealing ability of each tested material at three different experimental periods; one day, one week and one month after setting. All data were tabulated and statistically analyzed with a level of significance set at P ≤ .05.

Results

At each specific time interval, the leakage mean values were not consistent among the tested materials. At one day interval, ProRoot MTA samples had a higher leakage mean value than Biodentine samples. However, this difference in leakage was not statistically significant (P > .05). At one week interval, both materials showed an increased degree of leakage mean value with no significant difference (P > .05). At one month interval, ProRoot MTA samples showed a decrease in leakage mean value, while the Biodentine samples showed a further increase in leakage mean value. This difference was statistically significant (P < .05).

Conclusion

Although the sealing ability of ProRoot MTA is superior to Biodentine, Biodentine could be considered as an acceptable alternative to ProRoot MTA in peri-radicular surgeries.

Comparative evaluation of microleakage of mineral trioxide aggregate and Geristore root-end filling materials in different environments: An in vitro study

Aim:

The aim of this in vitro study was to evaluate and compare the microleakage of mineral trioxide aggregate (MTA) and Geristore root-end filling materials in different environments.

Materials and Methods:

After removing the anatomical crowns of ninety extracted human maxillary central incisors, their root canals were instrumented and obturated. The apical 3 mm of each root was resected, and a standardized root-end cavity was prepared using an ultrasonic tip. The roots were alienated into three equal subgroups for each material and the root-end filling was performed in different environments namely dry, saliva contaminated, and blood contaminated. Samples were immersed in 0.2% Rhodamine B dye for 48 h. Roots were sectioned longitudinally and examined under a fluorescent microscope to measure the linear dye penetration. The results were statistically analyzed using analysis of variance and Tukey's honestly significant difference post hoc test.

Results:

The Geristore dry group illustrated the lowest linear leakage, while the MTA saliva-contaminated group illustrated the highest leakage. In dry environment, linear dye penetration of both MTA and Geristore groups did not show any significant difference. However, statistically significant difference was observed between MTA and Geristore groups in blood- and saliva-contaminated environments.

Conclusion:

Geristore showed better results in saliva- and blood-contaminated environments; hence, Geristore may be used as an alternative to MTA for root-end filling.

A Comparative Evaluation of Sealing Ability of New MTA Based Sealers with Conventional Resin Based Sealer: An In-vitro Study

INTRODUCTION

Root canal obturation is the most important step in the root canal treatment that aims to obtain a complete hermetic seal and to prevent the re-growth of microorganisms in the root canal system. To accomplish this, many endodontic obturation materials and sealers are being used.

AIM

To evaluate and compare the apical microleakage of a resin based sealer; Adseal with Mineral Trioxide Aggregate (MTA) based sealers; Pro root MTA and MTA Fillapex.

MATERIALS AND METHODS

Total 75 extracted human single rooted teeth were taken and decoronated at cemento-enamel junction. The access cavities and biomechanical preparation were performed using endodontic rotary system. The teeth were randomly divided into five groups with n=15; Group I - Gutta-percha and Adseal sealer; Group II - Gutta-percha and MTA Fillapex; Group III- Gutta-percha and Pro root MTA; Group IV- Gutta-percha without sealer (positive control group); Group V- Root canal remained empty (negative control). All the specimens were stored at 37(0)C with 100% humidity for one week. All root surfaces except the apical 2mm were covered with two layers of nail varnish and then immersed in an aqueous solution of 2% methylene blue dye for 72 hours. Roots were longitudinally split using a diamond disk. Linear apical dye penetration was measured under Stereomicroscope at 40X magnification.

STATISTICAL ANALYSIS

The data obtained was subjected to statistical analysis using paried t-test, ANOVA for interclass comparison, with SPSS statistical software (version 20.0).

RESULTS

The intraobserver reliability was found to be insignificant in each of the triplicate study of all the three study samples. MTA Fillapex group showed maxmium apical microleakage followed by Pro root MTA and Adseal sealer.

CONCLUSION

The results concluded that Adseal sealer showed minimal dye penetration followed by Pro root MTA and MTA Fillapex. Thus, concluding that Adseal sealer is better in apical sealing than Pro root MTA and MTA Fillapex.

Assessment of apical seal obtained after irrigation of root end cavity with MTAD followed by subsequent retrofilling with MTA and Biodentine: An in vitro study

Introduction:

The present study is designed to assess the apical seal obtained after root end cavity irrigation with MTAD and retrograde filling with mineral trioxide aggregate (MTA) and Biodentine.

Materials and Methods:

Sixty extracted maxillary central incisors were instrumented and obturated. Apical 3 mm of all the roots were resected and retrograde preparations of 3 mm were made in all the teeth using ultrasonic tips. Thirty root end preparations were irrigated with MTAD for 5 min (Group 1), while 30 were irrigated with saline for 5 min (Group 2). Each main group was subdivided into two subgroups containing 15 samples each. Samples under each subgroup were then filled either with MTA (1A and 2A) or Biodentine (1B and 2B). The amount of microleakage was assessed using a UV spectrophotometer.

Results:

Statistical analysis suggest a significant difference (P < 0.005) between group 1A and 2A and between the groups 1B and 2B (P < 0.1). There was a significant difference (P < 0.005) between group 1A and 1B and also between group 2A and 2B.

Conclusion:

Irrigation with MTAD significantly improved the apical seal of Biodentine, but it increased the microleakage in MTA-filled root end cavities. Also the apical seal obtained with Biodentine was superior to that obtained with MTA.

Evaluation of smear layer removal from ultrasonically prepared retrocavities by three agents

OBJECTIVES

To evaluate the efficacy of 35% orthophosphoric acid, 24% ethylenediaminetetraacetic acid (EDTA) and 10% citric acid in the removal of smear layer from retrocavities prepared with ultrasonic retro-tips using scanning electron microscopy.

MATERIALS AND METHODS

Root canals of fifty single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and AH plus sealer. The apical 3 mm of each root was sectioned with a diamond disc and retrograde cavities were prepared with Kis # 1 ultrasonic retro-tips to a depth of 3 mm. Retro cavities in Group I were treated with a gel of 35% orthophosphoric acid for 15 seconds, Group II were treated with a gel of 24% EDTA at neutral pH for 2 minutes, and Group III were treated with a gel of 10% citric acid for 2 minutes, followed by 1 minute rinsing with distilled water for all groups. The samples were prepared for scanning electron microscopic observation. Scoring was performed for the presence of the smear layer on the walls of the retrocavity.

RESULTS

In the orthophosphoric acid group, it was observed that all dentinal tubules were open in 70% of the samples. The majority of analyzed samples in EDTA and citric acid group showed dentinal tubules covered with the smear layer.

CONCLUSIONS

Application of 35% orthophosphoric acid gel for 15 seconds on retrocavities prepared with ultrasonic retro-tips is the most effective means for removal of smear layer.

In vitro comparative study of sealing ability of Diadent BioAggregate and other root-end filling materials

AIM

This in vitro study evaluated and compared sealing ability of Diadent BioAggregate (DBA) as a new root-end filling material (REFM) versus amalgam, intermediate restorative material (IRM) and white mineral trioxide aggregate (WMTA).

MATERIALS AND METHODS

Crowns of sixty extracted human maxillary incisors were sectioned at the cemento-enamel junction (CEJ). All the roots were instrumented and obturated with gutta-percha and resin sealer. Obturated roots were divided randomly into 2 control groups and 4 experimental groups of 10 samples each. In the negative control group (group I), roots were kept without any further preparation. In the positive and experimental groups roots, were apically resected and root-end cavities were prepared and filled with: (a) gutta-percha (group 2-positive control group); (b) amalgam (group 3); (c) IRM (group 4); (d) WMTA (group 5); (e) DBA (group 6). Apical leakage was assessed using dye penetration technique. Data were submitted to statistical analysis by the one-way analysis of variance (ANOVA) and Tukey's test.

RESULTS

Significant difference of sealing ability was found among 4 tested groups. DBA followed by MTA showed the highest sealing ability.

CONCLUSIONS

DBA with its high sealing ability can be considered a possible alternative to MTA.

Ex vivo microscopic assessment of factors affecting the quality of apical seal created by root-end fillings

AIM

(i) To evaluate the incidence of microcracks around root-end preparations completed with ultrasonic tips and their relationship with the root filling technique and thickness of surrounding dentine. (ii) To investigate the effect of rapid exposure to a water-soluble dye of Intermediate Restorative Material (IRM), Super Ethoxybenzoic Acid (sEBA) and Mineral Trioxide Aggregate (MTA), on the marginal adaptation and microleakage of root-end fillings. (iii) To describe the microstructure of the surface of root-end filling materials.

METHODOLOGY

Ninety-two single-rooted teeth were divided into two groups (n = 46) according to the root canal instrumentation/filling techniques. Group 1 consisted of specimens in which canal preparation was completed using a crown-down technique and then filled with the Thermafil system (TF group); Group 2 consisted of specimens in which canal preparation was completed using a step-back technique and lateral condensation (LC group). Following root-end resection and ultrasonic cavity preparation, the samples were further divided into three subgroups (n = 24) for root-end filling with IRM, sEBA or MTA. The ultrasonic preparation time was recorded. Eight teeth were kept as positive and 12 as negative controls. Following immersion in Indian ink for 7 days, all resected root surfaces were evaluated for the presence of microcracks and the cross-sectional area of root-end surface and root-end filling were measured to evaluate the thickness of the dentinal walls. Thereafter, the samples were sectioned longitudinally so as to assess the depth of dye penetration and marginal adaptation of root-end fillings. Negative controls longitudinally sectioned were used to describe microstructural characteristics of the root-end filling materials using scanning electron microscopic (SEM) techniques.

RESULTS

Although the thickness of dentinal walls between groups 1 and 2 was similar, the ultrasonic preparation time and number of microcracks were significantly higher (P < 0.001) in the TF group. Both groups had a significant correlation between microcracks and ultrasonic preparation time (P < 0.001). sEBA and IRM had better adaptation and less leakage compared with MTA. A SEM analysis displayed microstructural differences between the root-end filling materials.

CONCLUSION

Microcracks can occur independently of the thickness of dentinal walls and may be associated with the prolonged ultrasonic preparation time required for the removal of the root filling during root-end cavity preparation. Although sEBA and IRM had better behaviour than MTA regarding microleakage and marginal adaptation, it is possible that exposure of MTA to a water-soluble dye before achieving full set and its porous microstructure contributed to the results.