Dr. MH. Nekoofar

DDS, MSc, DoIBoE, PhD

Category: Publications

  • The Sealing Ability of Different Thicknesses of Orthograde Apical Plugs of Mineral Trioxide Aggregate in Comparison with Gutta-Percha and Sealer AH26

  • 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

  • The Sealing Ability of Different Thickness of Orthograde Apical Plug of Mineral Trioxide Aggregate in Comparison with Gutta-Percha and Sealer AH26

  • Anex Vivo Study to Assess the Compressive Strength of MTA and Two Commercial Calcium Silicate Cements

  • Comparative Study of the Porosity of Several Hydraulic Silicate Cements

  • Preliminary Investigation of Oral Lactobacilli as Potential Probiotics for Root Canal Treatment

  • Comparison of the Surface Microhardness of Several Calcium Silicate-Based Materials

  • Evaluation of Three Imaging Techniques for the Detection of Vertical Root Fractures in the Absence and Presence of Gutta‐Percha Root Fillings

    Aim To compare the accuracy of digital radiography (DR), multidetector computed tomography (MDCT) and cone beam computed tomography (CBCT) in detecting vertical root fractures (VRF) in the absence and presence of gutta-percha root filling. Methodology The root canals of 100 extracted human single-rooted teeth were prepared and randomly divided into four groups: two experimental groups with artificially fractured root and two intact groups as controls. In one experimental and one control group, a size 40, 0.04 taper gutta-percha cone was inserted in the root canals. Then DR, MDCT and CBCT were performed and the images evaluated. Statistical analyses of sensitivity, specificity and accuracy of each imaging technique in the presence and absence of gutta-percha were calculated and compared.

     Evaluation of three imaging techniques for the.pdf