Dr. MH. Nekoofar

DDS, MSc, DoIBoE, PhD

Tag: Mineral Trioxide Aggregate

  • Fracture Resistance of Immature Incisors Following Root Filling with Various Bioactive Endodontic Cements Using an Experimental Bovine Tooth Model

    Abstract

    Objective The aim of this study was to compare the fracture resistance of immature bovine roots when using ProRoot MTA, CEM Cement, and Biodentine as root filling materials. Materials and Methods An immature bovine tooth model was developed by removing the coronal and apical portions of 70 bovine incisors 8 mm above and 12 mm below the cementoenamel junction (CEJ). The specimens were then divided into five groups: ProRoot MTA, CEM Cement, Biodentine, gutta-percha/AH26 sealer, and control. All groups received a 5-mm apical plug with a temporary restorative material. Then, the remaining root canal space was filled with one of the afore-mentioned materials. After setting, the specimens were mounted in acrylic resin. Then, 3 mm coronal to the CEJ from the buccal side of the teeth and at a 135°angle to the long axis, the specimens were loaded until fracture.

    Results The specimens in the Biodentine (2196 N) and ProRoot MTA (2103 N) groups had significantly greater fracture resistance in comparison to the control group (p = 0.01). No significant difference was found between CEM Cement, gutta-percha and sealer AH26, and control groups. No significant differences occurred between the four experimental groups (p = 0.45).

    Conclusion Filling the root canal space with ProRoot MTA and Biodentine contributed to higher fracture resistance values.

    Keywords: Fracture Resistance, Mineral Trioxide Aggregate, CEM Cement, Biodentine

     Fracture Resistance of Immature Incisors Following Root Filling with Various Bioactive Endodontic Cements Using an Experimental Bovine Tooth Model.pdf

  • Crystalline Phases Involved in the Hydration of Calcium Silicate‐Based Cements: Semi‐Quantitative Rietveld X‐Ray Diffraction Analysis

    Abstract

    Chemical comparisons of powder and hydrated forms of calcium silicate cements (CSCs) and calculation of alterations in tricalcium silicate (Ca3SiO5) calcium hydroxide (Ca(OH)2) are essential for understanding their hydration processes. This study aimed to evaluate and compare these changes in ProRoot MTA, Biodentine and CEM cement. Powder and hydrated forms of tooth coloured ProRoot MTA, Biodentine and CEM cement were subjected to X-ray diffraction (XRD) analysis with Rietveld refinement to semi-quantitatively identify and quantify the main phases involved in their hydration process. Data were reported descriptively. Reduction in Ca3SiO5 and formation of Ca(OH)2 were seen after the hydration of ProRoot MTA and Biodentine; however, in the case of CEM cement, no reduction of Ca3SiO5 and no formation of Ca(OH)2 were detected. The highest percentages of amorphous phases were seen in Biodentine samples. Ettringite was detected in the hydrated forms of ProRoot MTA and CEM cement but not in Biodentine.

    Keywords: X-Ray Diffraction Analysis, Chemical Properties, Mineral Trioxide Aggregate

     Crystalline Phases Involved in the Hydration of Calcium Silicate‐Based Cements Semi‐Quantitative Rietveld X‐Ray Diffraction Analysis.pdf

  • Evaluation and Comparison of Occurrence of Tooth Discoloration after the Application of Various Calcium Silicate–based Cements: An Ex Vivo Study

    Abstract

    Introduction: Biodentine (Septodont, Saint Maur des Fossés, France), OrthoMTA (BioMTA, Seoul, Korea), and EndoSequence Root Repair Material (ERRM; Brasseler, Savannah, GA) have been developed to overcome the shortcomings of mineral trioxide aggregate (MTA). The purpose of this study was to compare tooth discoloration after the application of ProRoot MTA (Dentsply Tulsa Dental Products, Tulsa, OK) and 3 recently introduced calcium silicate-based cements in the presence and absence of blood.

    Methods: In total, 104 human anterior teeth were prepared; 96 were randomly divided into 2 groups (blood and saline contamination). Each group was subdivided into 4 experimental subgroups (n = 12) of ProRoot MTA, Biodentine, OrthoMTA, and ERRM that were used to fill the pulp chambers. The remaining 8 teeth served as the saline and blood groups. Color analysis of tooth crowns was performed using a spectroradiometer before the application of materials and at 24 hours, 1 month, and 6 months after application. Repeated measures analysis of variance was used to evaluate the effects of blood, material, and time on color change (ΔE*).

    Results: Tooth color change in all experimental groups increased over time (P < .05). Blood contamination significantly increased ΔE* (P < .05), but no significant difference occurred between the 4 groups in this respect in the presence of blood. However, in the absence of blood, the ΔE* of Biodentine and ERRM was significantly less than that of OrthoMTA (P < .05).

    Conclusions: There was no significant difference between tooth discolorations with materials in the presence of blood. However, in the absence of blood, Biodentine and ERRM exhibited less tooth discoloration than OrthoMTA.

    Keywords: Biodentine, Calcium Silicate–Based Cements, Endosequence Root Repair Material,
    Mineral Trioxide Aggregate, Tooth Discoloration.

     Evaluation and Comparison of Occurrence of Tooth Discoloration after the Application o.pdf

  • Effect of Varying Water-to-Powder Ratios and Ultrasonic Placement on the Compressive Strength of Mineral Trioxide Aggregate

    Abstract

    Introduction: The purpose of this study was to compare the compressive strength of mineral trioxide aggregate (MTA) when mixed with 2 different waterto-powder (WP) proportions using either hand or ultrasonic placement.

    Methods: Tooth-colored ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and white MTA Angelus (Angelus Soluc¸oes Odontologicas, Londrina, Brazil) were investigated. One gram of each MTA powder was mixed with either 0.34 or 0.40 g distilled water. The 4 groups were further divided into 2 groups of 5 specimens for each of the following techniques: conventional (ie, hand placement) and placement using indirect ultrasonic activation for 30 seconds.

    All specimens were subjected to compressive strength testing after 4 days. The results were statistically analyzed with multivariate analysis of variance and Tukey Honestly Significant Difference tests at a significance level of P < .05.

    Results: The mean compressive strength values of ProRoot MTA (84.17±22.68) were significantly greater than those of MTA Angelus (47.71±14.29) (P < .01). Specimens mixed with the 0.34 WP ratio had higher compressive strength values (72.85±25.77) than those mixed with the 0.40 WP ratio (56.69±24.85) (P < .05). The highest compressive strength values were recorded for ProRoot MTA specimens that were mixed in the 0.34 WP ratio, and then the samples were placed with ultrasonic activation (mean = 91.35 MPa). The lowest values were recorded for MTA Angelus samples that were mixed in the 0.40 WP ratio, and the specimens were placed without ultrasonic activation (mean = 36.36 MPa). Ultrasonic activation had no significant difference in terms of compressive strength.

    Conclusions: When using ProRoot MTA and MTA Angelus, higher WP ratios resulted in lower compressive strength values. Ultrasonication had no significant effect on the compressive strength of the material regardless of the WP ratio that was used. Therefore, adherence to the manufacturer’s recommended WP ratio when preparing MTA for use in dental applications is advised.

    Keywords: Compressive Strength, Mineral Trioxide Aggregate, Ultrasonic Agitation, Water-To-Powder Ratio.

     Effect of Varying Water-to-Powder Ratios and Ultrasonic.pdf

  • Effect of Bismuth Oxide on White Mineral Trioxide Aggregate: Chemical Characterization and Physical Properties

    Aim: To assess the effect of bismuth oxide (Bi2O3) on the chemical characterization and physical properties of White mineral trioxide aggregate (MTA) Angelus. Methodology Commercially available White MTA Angelus and White MTA Angelus without Bi2O3 provided by the manufacturer especially for this study were subjected to the following tests: Rietveld X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), compressive strength, Vickers microhardness test and setting time. Chemical analysis data were reported descriptively, and physical properties were expressed as means and standard deviations. Data were analysed using Student’s t-test and Mann–Whitney U test (P = 0.05).

    Results: Calcium silicate peaks were reduced in the diffractograms of both hydrated materials. Bismuth particles were found on the surface of White MTA Angelus, and a greater amount of particles characterized as calcium hydroxide was observed by visual examination on White MTA without Bi2O3. The material without Bi2O3 had the shortest final setting time (38.33 min, P = 0.002), the highest Vickers microhardness mean value (72.35 MPa, P = 0.000) and similar compressive strength results (P = 0.329) when compared with the commercially available White MTA Angelus containing Bi2O3.
    Conclusion: The lack of Bi2O3 was associated with an increase in Vickers microhardness, a reduction in final setting time, absence of Bi2O3 peaks in diffractograms, as well as a large amount of calcium and a morphology characteristic of calcium hydroxide in EDX/SEM analysis.

     Effect of bismuth oxide on white mineral trioxide.pdf

  • Marginal Adaptation of New Bioceramic Materials and Mineral Trioxide Aggregate: A Scanning Electron Microscopy Study

    This study aimed to compare the marginal adaptation of new bioceramic materials, Endosequence Root Repair Material (ERRM putty and ERRM paste), to that of mineral trioxide aggregate (MTA) as root end filling materials. 

    Materials and Methods : thirty six extracted human single-rooted teeth were prepared and obturated with gutta-percha and AH-26 sealer. the roots were resected 3 mm from the apex. Root-end cavities were then prepared with an ultrasonic retro-tip. the specimens were divided into three groups (n=12) and filled with MTA, ERRM putty or ERRM paste. Epoxy resin replicas from resected root-end surfaces and longitudinally sectioned roots were fabricated. The gaps at the material/dentin interface were measured using scanning electron microscope (SEM). Transversal, longitudinal and overall gap sized were measured for each specimen. The data were analyzed using the Kruskall-Wallis test. 
    Results: in transversal sections, no significant difference was found between MTA, ERRM putty and ERRM paste (P=0.31). However, in longitudinal sections, larger gaps were evident between the ERRM paste and dentinal walls compared to MTA and ERRM putty (P=0.002 and P=0.033, respectively). Considering the overall gap size values, the difference between three tested materials was not statistically significant (p=0.17). 
    Conculsion: within the limits of this study, the marginal adaptation of ERRM paste and putty was comparable to that of MTA. However, ERRM putty might be more suitable for filling the root-end cavities because of its superior adaption compared to ERRM paste in longitudinal sections 

     Marginal Adaptation of New Bioceramic Materials and Mineral Trioxide Aggregate A Scanning Electron Microscopy Study.pdf

  • The Effect of Various Mixing and Placement Techniques on the Compressive Strength of Mineral Trioxide Aggregate

    The aim of this study was to evaluate the effect of various mixing techniques including mechanical and manual mixing as well as the effect of ultrasonic agitation during placement on the compressive strength of mineral trioxide aggregate (MTA). Methods: Toothcolored ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and white MTA Angelus (Angelus Soluc¸~oes Odontologicas, Londrina, Brazil) were used. One gram of each powder was mixed with a 0.34-g aliquot of distilled water. Specimens were mixed either by mechanical mixing of capsules for 30 seconds at 4,500 rpm or by a saturation technique and the application of a condensation pressure of 3.22 MPa for 1 minute. Half of the specimens were placed in stainless steel molds and agitated using indirect ultrasonic activation. All specimens were subjected to compressive strength testing after 4 days.
    Results: The compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus (P < .05). The highest compressive strength values were recorded from ProRoot MTA samples that were mixed mechanically and placed using ultrasonic activation (mean = 101.71 MPa), whereas the lowest values were recorded for MTA Angelus samples that were mixed manually and placed without ultrasonic activation (mean = 53.47 MPa). Ultrasonically agitated groups had higher compressive strength values (P < .001). The specimens mixed mechanically had higher compressive strength values than those mixed manually (P < .05). Conclusions: The compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus. Mechanical mixing enhanced the compressive strength of the material. Regardless of the mixing techniques applied, ultrasonic agitation improved the compressive strength of the material. (J Endod 2013;39:111–114)

     The Effect of Various Mixing and Placement Techniques on.pdf

  • Unintentional Extrusion of Mineral Trioxide Aggregate: A Report of Three Cases

    Aim:Mineral trioxide aggregate (MTA) is the material of choice for apical barrier techniques during root canal treatment of teeth with open apices. However, the precise control of MTA during the placement of an apical plug is challenging. This article describes the outcomes of unintentional extrusion of MTA into the periradicular tissue during apical barrier treatment in three cases.
    Summary: Three cases of maxillary central incisors in adult patients with open apices were referred for treatment. After conventional access and canal preparation, MTA was placed into the apical portion of the root canals to act as an apical barrier/plug. A large increment of MTA was extruded in all cases. In Case 1, after a 4-year follow-up, the extruded MTA had resorbed and the periradicular lesion had healed. In Cases 2 and 3, after follow-up, the patients remained symptomatic and were scheduled for periradicular surgery. In Case 2, soft unset particles of MTA were present in the lesion and were curetted. In Case 3, the extruded MTA had set hard but was sandwiched between the
    oral mucosa and bone; its removal relieved the pain experienced on buccal palpation.
    Key learning points
    • Extruded MTA may not harden and may be associated with ongoing periapical irritation;
    • Extruded set MTA when encapsulated in the mucosa and not surrounded by bony
    matrix may act as a mechanical irritant on palpation;
    • Mineral trioxide aggregate should be confined to the root canal system;
    • Teeth where MTA has been extruded beyond the foramen should be followed-up
    to monitor the outcome.

     Unintentional extrusion of mineral.pdf

  • Bioactivity of EndoSequence Root Repair Material and Bioaggregate

    Aim: To evaluate the bioactivity of Bioaggregate (BA), EndoSequence Root Repair Material (ERRM), and white ProRoot Mineral trioxide aggregate (MTA). Methodology Sixty horizontal root sections with standardized canal spaces were divided randomly into 3 groups (n = 20) and filled with white ProRoot MTA (groups 1 and 2), BA (groups 3 and 4) or ERRM putty (groups 5 and 6). The specimens of groups 1, 3 and 5 (each of 10) were immersed in phosphatebuffered saline (PBS) for 1 week and those of groups 2, 4 and 6 (each of 10) for 2 months. After the experimental periods, the specimens were processed for scanning electron microscopy (SEM) observations. Precipitation of apatite crystals on the surfaces of the cements and/or at the dentine–cement interface was evaluated and analysed elementally by energy dispersive X-ray (EDX) instrument.
    Results: Analysis of specimens revealed various surface morphologies that were dependent on the material and immersion time in PBS. The formation of precipitates was observed on the surfaces of all materials at 1 week, which increased substantially over time. After 2 months, the surface of the cements was changed dramatically and consisted of a substantially greater amount of apatite aggregates. Interfacial layers in some areas of the dentine–cement interface were found only following 2 months of immersion. Precipitates on MTA revealed high peaks of Ca, Si and O after 1 week of immersion; after 2 months, high peaks of Ca, P and O were present. Precipitates on BA and ERRM displayed high Ca, P O peaks after both 1 week and 2 months.
    Conclusion: Exposure of MTA, BA and ERRM to PBS resulted in precipitation of apatite crystalline structures that increased over time. This suggests that the tested materials are bioactive.

     Bioactivity of EndoSequence Root Repair Material.pdf

  • Microstructure and Chemical Analysis of Blood‐Contaminated Mineral Trioxide Aggregate

    Aim: To test the hypothesis that blood contamination has a detrimental effect on the chemical properties of Mineral trioxide aggregate (MTA). Methodology The effects ofwhole, freshhuman blood on the microstructure and elemental chemistry of MTA were evaluated using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. The phase compositions of contaminated and uncontaminatedMTA were also analysed using X-ray diffraction analysis.
    Results: The hydration state of specimens partially mixed with blood were more complete than those mixed entirely with blood and less than those entirely mixed with water. Acicular crystals, characteristic of ettringite, were abundant in specimens mixed entirely with water and absent from specimens mixed partially or entirely with blood. Calcium hydroxide crystals were absent in specimens contaminated entirely with blood and the unhydrated MTA powder, but present in the other groups.
    Conclusion: Mixing MTA with blood resulted in the lack of formation of the crystalline calcium hydroxide in the early stage of the hydration process.

     Microstructure and chemical analysis of.pdf