Dr. MH. Nekoofar

DDS, MSc, DoIBoE, PhD

Author: admin

  • Second-Generation Platelet Concentrate (Platelet-Rich Fibrin) as a Scaffold in Regenerative Endodontics: A Case Series

    Abstract

    Introduction: The purpose of this case series was to report the clinical and radiographic results of a pulp regenerative procedure using platelet-rich fibrin (PRF), a second-generation platelet concentrate, in immature teeth with necrotic pulps.

    Methods: Root canal revascularization using PRF was performed on 4 immature teeth with necrotic pulps. After access cavity preparation, the root canals were irrigated with low concentration sodium hypochlorite solution (1.5% sodium hypochlorite [20 mL/canal, 5 minutes]) and then irrigated with saline (20 mL/canal, 5 minutes). Equal proportions (167 mg) of ciprofloxacin, metronidazole, and cefaclor were mixed and diluted to a final concentration of 1 g/mL. Finally, the canal was sealed with 3-4 mm of a temporary restorative material, and patients were dismissed for 2 to 3 weeks. At the second appointment, 9 mL of the patient’s whole blood was obtained and centrifuged to prepare a PRF clot. Canals were irrigated with 17% EDTA, and a sharp spreader was inserted beyond the apex. Then, the PRF clot was placed inside the root canals, and Biodentine (Septodont, Saint-Maur, France) was placed directly over the PRF. The teeth were restored permanently with glass ionomer cement and composite resin.

    Results: Clinical examinations revealed that all cases were asymptomatic at the recall appointments at 1, 3, 6, 12, and 18 months. Radiographs revealed resolution of the periapical lesions, further root development, and apical closure in all cases.

    Conclusions: On the basis of the short-term results up to 12 months, PRF clots acted as successful scaffolds for the regeneration of pulpal contents in immature teeth with necrotic pulps.

    KEYWORDS: Open Apex, Platelet-Rich Fibrin, Regenerative Endodontics, Revascularization; Second-Generation Platelet Concentrate.

     Second-Generation Platelet Concentrate (Platelet-Rich Fibrin) as a Scaffold in Regenerative Endodontics A Case.pdf

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  • 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

  • Comparison of the Effect of Root Canal Preparation by Using WaveOne and ProTaper on Postoperative Pain: A Randomized Clinical Trial

    Abstract

    Introduction: WaveOne is a single-file reciprocating instrumentation system with the benefits of M-Wire alloy that has increased flexibility and improved resistance to cyclic fatigue over the conventional alloy. Root canal preparation techniques may cause postoperative pain. The goal of the present study was to compare the intensity and duration of postoperative pain when using WaveOne or ProTaper Universal systems for instrumentation of root canals.

    Methods: Forty-two patients who fulfilled specific inclusion criteria were assigned to 2 groups according to the root canal instrumentation technique used, WaveOne or ProTaper Universal. Root canal treatment was carried out in 2 appointments, and the severity of postoperative pain was assessed by numerical rating scale (NRS) score after each session until complete pain relief was achieved. Analgesic consumption, duration of pain, and root canal preparation time were also recorded.

    Results: The mean NRS score and duration of pain after both appointments were significantly higher in the WaveOne group (P < .05); however, the mean analgesic consumption was only significantly higher in the WaveOne group after the first appointment (P < .05). In all groups the highest mean NRS score was seen 6 hours after each therapeutic appointment. Canal preparation time was significantly shorter in the WaveOne group (P < .001).

    Conclusions: Postoperative pain was significantly lower in patients undergoing canal instrumentation with ProTaper Universal rotary instruments compared with the WaveOne reciprocating single-file technique.

    Keywords: Postoperative Pain, Protaper, Waveone.

     Comparison of the Effect of Root Canal Preparation- June 2014.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

  • Influence of Tooth Length on the Accuracy of the Root ZX Electronic Apical Foramen Locator: An Ex Vivo Study

    Abstract

    Objective: Electronic apical foramen locators are now widely used to determine working length. This study was designed to determine whether tooth length influenced the accuracy of the Root ZX device.

    Materials and methods: Forty extracted maxillary canine teeth with a length range of 27-29 mm were selected. Access cavities were prepared and coronal flaring of canals performed. The teeth were mounted in self-polymerizing acrylic resin to facilitate horizontal sectioning except for the apical 3-4-mm portion of the root and embedded in alginate as the electronic medium. Electronic measurements were taken at the major foramen, ‘zero’ reading using the Root ZX and compared with the actual root canal length. The teeth were sectioned 3 mm from the coronal reference point to create a second group with shorter length; these reductions in the length continued six times in all to create seven groups of 40 specimens each. The actual and electronic lengths of specimens in each group were measured. Data were analyzed by Pearson’s correlation coefficient.

    Results: Identical measurements between the actual and electronic root canal length from the longest to the shortest groups were 12.5%, 10.0%, 20.0%, 27.5%, 37.5%, 35.0% and 45.0%, respectively. There was a mild negative correlation between the precise measurements of the Root ZX and root canal lengths in the seven groups (r = -0.964, p < 0.001).

    Conclusion: Under the conditions of the study, the Root ZX device was more accurate in shorter teeth compared to longer ones.

    Keywords: Apical foramen; Root ZX; electronic apex locators; tooth length; working length.

     Influence of tooth length on the accuracy of the Root ZX electronic apical.pdf

  • Surface Microhardness of Three Thicknesses of Mineral Trioxide Aggregate in Different Setting Conditions

    Objectives: This study aimed to compare the surface microhardness of mineral trioxide aggregate (MTA) samples having different thicknesses and exposed to human blood from one side and with or without a moist cotton pellet on the other side. Materials and Methods: Ninety cylindrical molds with three heights of 2, 4, and 6 mm were fabricated. In group 1 (dry condition), molds with heights of 2, 4, and 6 mm (10 molds of each) were filled with ProRoot MTA (Dentsply Tulsa Dental), and the upper surface of the material was not exposed to any additional moisture. In groups 2 and 3, a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet was placed on the upper side of MTA, respectively. The lower side of the molds in all the groups was in contact with human blood-wetted foams. After 4 day, the Vickers microhardness of the upper surface of MTA was measured. Results: In the dry condition, the 4 and 6 mm-thick MTA samples showed significantly lower microhardness than the 2 mm-thick samples (p = 0.003 and p = 0.001, respectively). However, when a distilled water- or PBS-moistened cotton pellet was placed over the MTA, no significant difference was found between the surface microhardness of samples having the abovementioned three thicknesses of the material (p = 0.210 and p = 0.112, respectively). Conclusions: It could be concluded that a moist cotton pellet must be placed over the 4 to 6 mm-thick MTA for better hydration of the material. However, this might not be necessary when 2 mm-thick MTA is used. (Restor Dent Endod 2014;39(4):253-257)

     Surface microhardness of three thicknesses of.pdf

  • In Vitro Cytotoxicity of Four Calcium Silicate-Based Endodontic Cements on Human Monocytes, a Colorimetric MTT Assay

    Objectives: This study was performed to evaluate the cytotoxicity of four calcium silicate-based endodontic cements at different storage times after mixing. Materials and Methods: Capillary tubes were filled with Biodentine (Septodont), Calcium Enriched Mixture (CEM cement, BioniqueDent), Tech Biosealer Endo (Tech Biosealer) and ProRoot MTA (Dentsply Tulsa Dental). Empty tubes and tubes containing Dycal were used as negative and positive control groups respectively. Filled capillary tubes were kept in 0.2 mL microtubes and incubated at 37℃. Each material was divided into 3 groups for testing at intervals of 24 hr, 7 day and 28 day after mixing. Human monocytes were isolated from peripheral blood mononuclear cells and cocultered with 24 hr, 7 day and 28 day samples of different materials for 24 and 48 hr. Cell viability was evaluated using an MTT assay. Results: In all groups, the viability of monocytes significantly improved with increasing storage time regardless of the incubation time (p < 0.001). After 24 hr of incubation, there was no significant difference between the materials regarding monocyte viability. However, at 48 hr of incubation, ProRoot MTA and Biodentine were less cytotoxic than CEM cement and Biosealer (p < 0.01).
    Conclusions: Biodentine and ProRoot MTA had similar biocompatibility. Mixing ProRoot MTA with PBS in place of distilled water had no effect on its biocompatibility. Biosealer and CEM cement after 48 hr of incubation were significantly more cytotoxic to on monocyte cells compared to ProRoot MTA and Biodentine. (Restor Dent Endod 2014;39(3):149-154)

     In vitro cytotoxicity of four calcium silicate-based.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

  • Effect of Acidic Environment on Dislocation Resistance of Endosequence Root Repair Material and Mineral Trioxide Aggregate

    Objective: The aim of this study was to compare the effect of an acidic environment on dislocation resistance (push-out bond strength) of EndoSequence Root Repair Material (ERRM putty and ERRM paste), a new bioceramic-based material, to that of mineral tri-oxide aggregate (MTA).
    Materials and Methods: One-hundred twenty root dentin slices with standardized canal spaces were divided into 6 groups (n = 20 each) and filled with tooth-colored ProRoot MTA (groups 1 and 2), ERRM putty (groups 3 and 4), or ERRM paste (groups 5 and 6). The specimens of groups 1, 3, and 5 were exposed to phosphate buffered saline (PBS) so-lution (pH=7.4) and those of groups 2, 4, and 6 were exposed to butyric acid (pH= 4.4). The specimens were then incubated for 4 days at 37°C. The push-out bond strength was then measured using a universal testing machine. Failure modes after the push-out test were examined under a light microscope at ×40 magnification. The data for dislocation resistance were analyzed using the t-test and one-way analysis of variance.
    Results: In PBS environment (pH=7.4), there were no significant differences among ma-terials (P=0.30); but the mean push-out bond strength of ERRM putty was significantly higher than that of other materials in an acidic environment (P<0.001). Push-out bond strength of MTA and ERRM paste decreased after exposure to an acidic environment; whereas ERRM putty was not affected by acidic pH. The bond failure mode was predomi-nantly cohesive for all groups except for MTA in an acidic environment; which showed mixed bond failure in most of the specimens.
    Conclusion: The force needed for dislocation of MTA and ERRM paste was significantly lower in samples stored in acidic pH; however, push-out bond strength of ERRM putty was not influenced by acidity.

     Effect of Acidic Environment on Dislocation Resistance of.pdf