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Papers by Negin Ghasemi

Aims: The present study was carried out to evaluate the relationship between the grades of pre-cl... more Aims: The present study was carried out to evaluate the relationship between the grades of pre-clinical and clinical courses of endodontics, fixed prosthodontics and restorative dentistry achieved by dental students entering Tabriz Faculty of Dentistry in 2009, 2010 and 2011. Materials and methods: The subjects in this retrospective cross-sectional study consisted of dental students entering Tabriz Faculty of Dentistry in 2009, 2010 and 2011 (n=48 students each year). The grades of the students in restorative dentistry, fixed prosthodontists, endodontics I (pre-clinic) and endodontics II (clinic) courses were recorded by referring to the Archives of the Education Office of the Faculty. The means and standard deviations of the grades were calculated. T-test was used to compare the means and standard deviations with SPSS. Statistical significance was set at P<0.05. Results: There were significant differences in all the grades between the clinical and pre-clinical lessons (P<0.05...

Paripex Indian Journal Of Research, 2016

Introduction Educators need evidence-based guidance on how to develop effective e-learning in den... more Introduction Educators need evidence-based guidance on how to develop effective e-learning in dentistry.The purpose of this literature review is to update previously published information and present a com-prehensive list of articles regarding e-learning. Method A review of the literature was performed by using electronic and hand searching methods for e-learning from May 2000 to July 2015. Results The overall perceptions of online learning were positive, and although there were some frustrations, the majority of students reported learned a great deal, found the course valuable, and became familiar with the terminology; but there are concerns and challengesin relation to the value of online learning. Conclusions Although the experience of developing and using online courses was new in much dental school, the study results revealed that the program was feasible effective. It seems that combination of classroom and online education was the ideal teaching methodology .

BACKGROUND The aim of the present study was to compare the efficacy of Nd:YAG laser and K3 rotary... more BACKGROUND The aim of the present study was to compare the efficacy of Nd:YAG laser and K3 rotary system in the non-surgical root canal retreatment. METHODS Sixty-one rooted human teeth were divided into two groups of 30 after root canal therapy. In groups 1 and 2 root canal retreatments were carried out using K3 rotary system and Nd:YAG laser, respectively. CBCT images were used to evaluate canal transportation and root canal debridement at coronal, middle and apical canal cross-sections. In addition, the time necessary for canal debridement and the temperature on the external root surface were calculated. Mann-Whitney U test was used for statistical analysis of data with SPSS 17 after means ± SD were calculated. Shapiro-Wilk test was used to evaluate normal distribution of data. Statistical significance was defined at P<0.05. RESULTS The mean time necessary for the debridement of root canals in the laser group was significantly shorter than that in the K3 group (P=0.001). Howev...

1. Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of M... more 1. Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 2. Dentist, Hospital of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 3. Assistant Professor , Department of Nutritional Science, Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran. 4. Associate Professor, Department of Oral Medicine, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran 5. Dentist,Tabriz,Iran 6. Assistant professor, Department of Endodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 7. Assistant professor, Department of Operative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran

BACKGROUND Calcium-Enriched Mixture Cement is used in the field of endodontics. It is similar to ... more BACKGROUND Calcium-Enriched Mixture Cement is used in the field of endodontics. It is similar to Mineral Trioxide Aggregate in its main ingredients.The present study investigated the effect of different mixing methods on the bacterial microleakage of CEM cement. METHODS A total of 55 human single-rooted human permanent teeth were decoronated so that 14- mm-long samples were obtained and obturated with AH26 sealer and gutta-percha using lateral condensation technique. Three millimeters of the root end were cut off and randomly divided into 3 groups of 15 each (3 mixing methods of amalgamator, ultrasonic and conventional) and 2 negative and positive control groups (each containing 5 samples). BHI (Brain-Heart Infusion Agar) suspension containing Enterococcus faecalis was used for bacterial leakage assessment. Statistical analysis was carried out using descriptive statistics, Kaplan‒Meier survival analysis with censored data and log rank test. Statistical significance was set at P<0...

Introduction: It is necessary to carry out studies, prepare programs and rethink in order to rend... more Introduction: It is necessary to carry out studies, prepare programs and rethink in order to render an effective clinical training. Changes in educational curricula should accommodate changes in oral health, dental community needs and changes, advances and technologies in the dental field. The present study was undertaken to evaluate the quality of the new educational curriculum of dentistry ratified by the Ministry of Health, Treatment and Medical Education. This evaluation was carried out by the professors in Faculty of Dentistry, Tabriz University of Medical Sciences. Materials and methods: In this descriptive analytical study, 35 professors in Tabriz Faculty of Dentistry expressed their opinions about the new educational curriculum of dentistry by completing a questionnaire. The validity and reliability of the questionnaire was confirmed by the professors in Tabriz University of Medical Sciences and its validity was confirmed by a Cronbach's alpha. Results: Thirty-five professors in Tabriz Faculty of Dentistry participated in the study, with a female rate of 45.7%. The mean job experience of the professors was 9.2±7.4 years. Based on the results, the educational curriculum was favorable in relation to aims, content and active teaching techniques; 31.7% of the professors believed that the new educational curriculum was unfavorable in relation to learning activities. In addition, 17.1% of the professors believed the time allocation of the new curriculum was unfavorable. Conclusion: Based on the opinions of the professors in Tabriz Faculty of Dentistry, the new educational curriculum of dentistry has proper quality in general. Revision of the learning activities and the time allocation can give rise to improvements in the quality of the new educational curriculum.

Background: Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) inc... more Background: Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA. Material and Methods: The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property. Data were analyzed using descriptive statistics and T-test. Statistical significance was set at P<0.05. Results: There was the significant effect of the material type (presence and absence of TiO2 nanoparticles) on the push-out bond strength, compressive strength, working time and setting time, with significantly higher values achieved in the group with TiO2 nanoparticles than the group with...

Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Student Research Workshop

Journal of Dental Research, Dental Clinics, Dental Prospects

Background. It is difficult to achieve successful pulpal anesthesia in mandibular posterior teeth... more Background. It is difficult to achieve successful pulpal anesthesia in mandibular posterior teeth with symptomatic irreversible pulpitis. The present study aimed to compare the effect of articaine/epinephrine anesthesia with articaine/epinephrine at a combination of 0.5 mol/mL of mannitol for the inferior alveolar nerve block (IANB) in patients presenting with symptomatic irreversible pulpitis in the mandibular first molar tooth. Methods. One hundred patients with symptomatic irreversible pulpitis in the mandibular first molar tooth were selected and randomly divided into two groups based on the injection method. The first group underwent an IANB technique with 1.8 mL of articaine, whereas the second group received 2.9 mL of a formulation, consisting of 1.8 mL of articaine plus 1.1 mL of 0.5 mol/L of mannitol. Fifteen minutes after injections and anesthesia of the lip, the access cavity was prepared. According to the visual analog scale (VAS) criteria, no pain or mild pain for carie...

Journal of Dental Research, Dental Clinics, Dental Prospects

Background. The aim of this in vitro study was to investigate the effect of zinc oxide (ZnO) and ... more Background. The aim of this in vitro study was to investigate the effect of zinc oxide (ZnO) and zirconium oxide (ZrO2) microparticles (MPs) and nanoparticles (NPs) in combination with white Portland cement (WPC) on odontogenic capacity of human dental pulp stem cells over a period of 21 days. Methods. Synthesized ZnO and ZrO2 particles were characterized using scanning electron microscopy and transmission electron microscopy. The viability of human dental pulp stem cells was measured by a 3-(4,5-dimethylthiazolyl-2-yl)-2,5- diphenyltetrazolium bromide assay at 7-, 14- and 21-day intervals after seeding on WPC disks enriched with ZnO and ZrO2 MPs and NPs. Odontogenic potential of ZnO and ZrO2 particles in combination with WPC was investigated by alkaline phosphatase (ALP) activity and ionized calcium level of supernatant culture media at different time intervals. Data were analyzed using one-way ANOVA and post hoc Tukey tests. Results. All the materials exhibited cell viability over...

Journal of clinical and experimental dentistry, 2017

Presence of voids at root canal wall‒apical seal material interface gives rise to the entrapment ... more Presence of voids at root canal wall‒apical seal material interface gives rise to the entrapment of toxins and microorganisms, which might have a relationship with post treatment disease. The present study was carried out to evaluate the effect of different mixing (manual and ultrasonic) and placement (manual and manual in association with indirect ultrasonic) methods of Calcium-enriched Mixture (CEM) cement on the number and dimensions of voids in the apical plug in simulated apexification models. A total of 80 human maxillary central incisors with mature apices were selected. After simulation of the open apices, the teeth were divided into 4 groups (n=20) based on the mixing and placement techniques of CEM cement: group 1, manual mixing‒manual placement; group 2, manual mixing‒manual placement in association with indirect ultrasonic technique; group 3, ultrasonic mixing‒manual placement; and group 4, ultrasonic mixing‒manual placement in association with indirect ultrasonic techni...

Journal of Clinical and Experimental Dentistry

Background: This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Z... more Background: This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Ze-Ag-Zn) nanoparticles and their effect on the compressive strength of Mineral Trioxide Aggregate (MTA). Material and Methods: Biocompatibility was evaluated by an MTT assay on the pulmonary adenocarcinoma cells with 0.05, 0.1, 0.25, 0.5, 1 and 5 mg/mL concentrations of Ze-Ag-Zn. For compressive strength test, four groups containing 15 stainless-steel cylinders with an internal diameter of 4 and a height of 6 mm were prepared and MTA (groups 1 and 2) or MTA + 2% Ze-Ag-Zn (groups 3 and 4) were placed in the cylinders. The compressive strength was evaluated using a universal testing machine 4 days after mixing in groups 1 and 3, and 21 days after mixing in groups 2 and 4. Results: There was no significant difference between cytotoxicity of different concentrations. The highest (52.22±18.92 MPa) and lowest (19.57±5.76 MPa) compressive strength were observed in MTA group after 21 days and in MTA + 2% Ze-Ag-Zn group after four days, respectively. The effect of time and 2% Ze-Ag-Zn on the compressive strength were significant (P<0.05). Mixing MTA with Ze-Ag-Zn significantly reduced and passage of time from day four to 21 significantly increased the compressive strength. Conclusions: Mixing MTA with 2% Ze-Ag-Zn had an adverse effect on the compressive strength of MTA, but this combination had no cytotoxic effects.

Journal of Clinical and Experimental Dentistry

Background: One of the essential properties of the root canal sealers is the adhesion to root can... more Background: One of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers. Material and Methods: A total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH) 2 , triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the subgroups were obturated with gutta-percha and AH26 or MTA Fillapex sealers. After two weeks incubation, 2-mm-thick middle section of each root was then subjected to push-out testing. Data were analyzed with two-way ANOVA and LSD test. Results: With all the intracanal medicaments, the overall mean of bond strength values were significantly higher with AH26 compared to MTA Fillapex (p<0.05). With the use of MTA Fillapex the maximum and minimum means of bond strength values were recorded with CHX and Metapex and for AH26 were recorded with Ca(OH) 2 and chlorhexidine, respectively.

Journal of Clinical and Experimental Dentistry

Selective properties of MTA with TiO 2 nanoparticles e191

Journal of Clinical and Experimental Dentistry

Background: Proper bond strength to dentin is one of the properties of biomaterials used for ther... more Background: Proper bond strength to dentin is one of the properties of biomaterials used for therapeutic purposes such as repair of furcal perforations. The aim of the present study to evaluate the effects of different powder to liquid ratios of Calcium-enriched mixture (CEM) on the push-out bond strengths in simulated perforations in the furcal area and compare it with Mineral trioxide aggregate (MTA). Material and Methods: Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were prepared in 120 mandibular first molars. Then the samples were randomly assigned to two groups (n=60). MTA and CEM cement were used for the repair of perforations in groups 1 and 2, respectively. Each group was divided into 3 subgroups based on the powder to liquid rations as follows: subgroup 1 (W/P) , 1:2; subgroup 2, 1:3; and subgroup 3, 1:4. After mixing and placing the materials in the perforation area, the samples were placed in closed containers at 37°C and 100% relative humidity for one week. A universal testing machine was used to determine the bond strength values. After recording the standard deviations, data were analyzed with two-way ANOVA. Statistical significance was set at P<0.05. Results: In the MTA and CEM groups the highest push-out bond strength values were recorded in the third (W/P: 1:4) and first (W/P: 1:2) subgroups, respectively. There were significant differences in both groups between the ratios mentioned above and the other ratios (P<0.05). Conclusions: Under the limitations of the present study, an increase in the powder-to-liquid ratio in CEM cement resulted in a decrease in bond strength, contrary to MTA.

Journal of Clinical and Experimental Dentistry

Bond strength of endodontic sealers after Photodynamic therapy and irrigation with nanoparticles ... more Bond strength of endodontic sealers after Photodynamic therapy and irrigation with nanoparticles e1109

Iranian endodontic journal, 2016

The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral triox... more The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral trioxide aggregate (MTA) liquid with volume ratio of 20% on the compressive strength (CS) of MTA in two time periods (4 and 21 days) after mixing. Four groups of steel cylinders (n=15) with an internal diameter of 3 and a height of 6 mm were prepared and MTA (groups 1 and 2) and MTA+PG (80% MTA liquid+20% PG) (groups 3 and 4) were placed in to the cylinders. In groups 1 and 3 the CS was evaluated after 4 days and in groups 2 and 4 after 21 days. Data were calculated using the two-ways ANOVA. The level of significance was set at 0.05. The highest (52.22±18.92 MPa) and lowest (4.5±0.67 MPa) of CS was obtained in 21-day MTA samples and 4-day MTA+PG specimen, respectively. The effect of time and PG were significant on the CS (P<0.05). Mixing MTA with PG significantly reduced the CS; but passing the time from 4 to 21 days significantly increased the CS. Considering the limitations of this study...

Iranian endodontic journal, 2017

The complexity of the root canal system presents a challenge for the practitioner. This systemati... more The complexity of the root canal system presents a challenge for the practitioner. This systematic review evaluated the papers published in the field of root canal anatomy and configuration of the root canal system in permanent maxillary second molars. All articles related to the root morphology and root canal anatomy of the permanent maxillary second molars were collected by suitable keywords from PubMed database. The exhaustive search included all publications from 1981 to December 2015. The articles relevant to the study were evaluated and data was extracted. The author/year of publication, country, number of the evaluated teeth, type of study (method of the evaluation), number of roots and the canals, type of canals and the morphology of the apical foramen was noted. The highest studied populations were in Brazil and United States. A total of 116 related papers were found, which had investigated 11945 teeth in total. Across all the studied populations, the three-rooted anatomy w...

Journal of clinical and experimental dentistry, 2016

Persistent infection of the root canal due to the presence of resistance bacterial species, such ... more Persistent infection of the root canal due to the presence of resistance bacterial species, such as Enterococcus faecalis, has always been one of the most important reasons for endodontic treatment failure. This study investigated the antimicrobial efficacy of 1%, 2.5 % and 5% sodium hypochlorite in eliminating E. faecalis biofilms at different stages of development. In this study 4-, 6- and 10-week-old E. faecalis biofilms were subjected to one of the following approaches: phosphate-buffered saline solution (PBS) or 1%, 2.5% and 5% NaOCl. Dentin chip suspensions were used for colony forming unit (CFU) counting to estimate remaining E. faecalis counts. Statistical comparison of the means was carried out with Kruskal-Wallis test, and pair-wise comparisons were made by Mann-Whitney U test, at a significance level of P<0.05. The results showed that 2.5% and 5% NaOCl completely eliminated E. faecalis biofilms in three stages of biofilm development, whereas 1% NaOCl resulted in 85.73%...

Aims: The present study was carried out to evaluate the relationship between the grades of pre-cl... more Aims: The present study was carried out to evaluate the relationship between the grades of pre-clinical and clinical courses of endodontics, fixed prosthodontics and restorative dentistry achieved by dental students entering Tabriz Faculty of Dentistry in 2009, 2010 and 2011. Materials and methods: The subjects in this retrospective cross-sectional study consisted of dental students entering Tabriz Faculty of Dentistry in 2009, 2010 and 2011 (n=48 students each year). The grades of the students in restorative dentistry, fixed prosthodontists, endodontics I (pre-clinic) and endodontics II (clinic) courses were recorded by referring to the Archives of the Education Office of the Faculty. The means and standard deviations of the grades were calculated. T-test was used to compare the means and standard deviations with SPSS. Statistical significance was set at P<0.05. Results: There were significant differences in all the grades between the clinical and pre-clinical lessons (P<0.05...

Paripex Indian Journal Of Research, 2016

Introduction Educators need evidence-based guidance on how to develop effective e-learning in den... more Introduction Educators need evidence-based guidance on how to develop effective e-learning in dentistry.The purpose of this literature review is to update previously published information and present a com-prehensive list of articles regarding e-learning. Method A review of the literature was performed by using electronic and hand searching methods for e-learning from May 2000 to July 2015. Results The overall perceptions of online learning were positive, and although there were some frustrations, the majority of students reported learned a great deal, found the course valuable, and became familiar with the terminology; but there are concerns and challengesin relation to the value of online learning. Conclusions Although the experience of developing and using online courses was new in much dental school, the study results revealed that the program was feasible effective. It seems that combination of classroom and online education was the ideal teaching methodology .

BACKGROUND The aim of the present study was to compare the efficacy of Nd:YAG laser and K3 rotary... more BACKGROUND The aim of the present study was to compare the efficacy of Nd:YAG laser and K3 rotary system in the non-surgical root canal retreatment. METHODS Sixty-one rooted human teeth were divided into two groups of 30 after root canal therapy. In groups 1 and 2 root canal retreatments were carried out using K3 rotary system and Nd:YAG laser, respectively. CBCT images were used to evaluate canal transportation and root canal debridement at coronal, middle and apical canal cross-sections. In addition, the time necessary for canal debridement and the temperature on the external root surface were calculated. Mann-Whitney U test was used for statistical analysis of data with SPSS 17 after means ± SD were calculated. Shapiro-Wilk test was used to evaluate normal distribution of data. Statistical significance was defined at P<0.05. RESULTS The mean time necessary for the debridement of root canals in the laser group was significantly shorter than that in the K3 group (P=0.001). Howev...

1. Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of M... more 1. Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 2. Dentist, Hospital of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 3. Assistant Professor , Department of Nutritional Science, Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran. 4. Associate Professor, Department of Oral Medicine, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran 5. Dentist,Tabriz,Iran 6. Assistant professor, Department of Endodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran 7. Assistant professor, Department of Operative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran

BACKGROUND Calcium-Enriched Mixture Cement is used in the field of endodontics. It is similar to ... more BACKGROUND Calcium-Enriched Mixture Cement is used in the field of endodontics. It is similar to Mineral Trioxide Aggregate in its main ingredients.The present study investigated the effect of different mixing methods on the bacterial microleakage of CEM cement. METHODS A total of 55 human single-rooted human permanent teeth were decoronated so that 14- mm-long samples were obtained and obturated with AH26 sealer and gutta-percha using lateral condensation technique. Three millimeters of the root end were cut off and randomly divided into 3 groups of 15 each (3 mixing methods of amalgamator, ultrasonic and conventional) and 2 negative and positive control groups (each containing 5 samples). BHI (Brain-Heart Infusion Agar) suspension containing Enterococcus faecalis was used for bacterial leakage assessment. Statistical analysis was carried out using descriptive statistics, Kaplan‒Meier survival analysis with censored data and log rank test. Statistical significance was set at P<0...

Introduction: It is necessary to carry out studies, prepare programs and rethink in order to rend... more Introduction: It is necessary to carry out studies, prepare programs and rethink in order to render an effective clinical training. Changes in educational curricula should accommodate changes in oral health, dental community needs and changes, advances and technologies in the dental field. The present study was undertaken to evaluate the quality of the new educational curriculum of dentistry ratified by the Ministry of Health, Treatment and Medical Education. This evaluation was carried out by the professors in Faculty of Dentistry, Tabriz University of Medical Sciences. Materials and methods: In this descriptive analytical study, 35 professors in Tabriz Faculty of Dentistry expressed their opinions about the new educational curriculum of dentistry by completing a questionnaire. The validity and reliability of the questionnaire was confirmed by the professors in Tabriz University of Medical Sciences and its validity was confirmed by a Cronbach's alpha. Results: Thirty-five professors in Tabriz Faculty of Dentistry participated in the study, with a female rate of 45.7%. The mean job experience of the professors was 9.2±7.4 years. Based on the results, the educational curriculum was favorable in relation to aims, content and active teaching techniques; 31.7% of the professors believed that the new educational curriculum was unfavorable in relation to learning activities. In addition, 17.1% of the professors believed the time allocation of the new curriculum was unfavorable. Conclusion: Based on the opinions of the professors in Tabriz Faculty of Dentistry, the new educational curriculum of dentistry has proper quality in general. Revision of the learning activities and the time allocation can give rise to improvements in the quality of the new educational curriculum.

Background: Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) inc... more Background: Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA. Material and Methods: The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property. Data were analyzed using descriptive statistics and T-test. Statistical significance was set at P<0.05. Results: There was the significant effect of the material type (presence and absence of TiO2 nanoparticles) on the push-out bond strength, compressive strength, working time and setting time, with significantly higher values achieved in the group with TiO2 nanoparticles than the group with...

Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Student Research Workshop

Journal of Dental Research, Dental Clinics, Dental Prospects

Background. It is difficult to achieve successful pulpal anesthesia in mandibular posterior teeth... more Background. It is difficult to achieve successful pulpal anesthesia in mandibular posterior teeth with symptomatic irreversible pulpitis. The present study aimed to compare the effect of articaine/epinephrine anesthesia with articaine/epinephrine at a combination of 0.5 mol/mL of mannitol for the inferior alveolar nerve block (IANB) in patients presenting with symptomatic irreversible pulpitis in the mandibular first molar tooth. Methods. One hundred patients with symptomatic irreversible pulpitis in the mandibular first molar tooth were selected and randomly divided into two groups based on the injection method. The first group underwent an IANB technique with 1.8 mL of articaine, whereas the second group received 2.9 mL of a formulation, consisting of 1.8 mL of articaine plus 1.1 mL of 0.5 mol/L of mannitol. Fifteen minutes after injections and anesthesia of the lip, the access cavity was prepared. According to the visual analog scale (VAS) criteria, no pain or mild pain for carie...

Journal of Dental Research, Dental Clinics, Dental Prospects

Background. The aim of this in vitro study was to investigate the effect of zinc oxide (ZnO) and ... more Background. The aim of this in vitro study was to investigate the effect of zinc oxide (ZnO) and zirconium oxide (ZrO2) microparticles (MPs) and nanoparticles (NPs) in combination with white Portland cement (WPC) on odontogenic capacity of human dental pulp stem cells over a period of 21 days. Methods. Synthesized ZnO and ZrO2 particles were characterized using scanning electron microscopy and transmission electron microscopy. The viability of human dental pulp stem cells was measured by a 3-(4,5-dimethylthiazolyl-2-yl)-2,5- diphenyltetrazolium bromide assay at 7-, 14- and 21-day intervals after seeding on WPC disks enriched with ZnO and ZrO2 MPs and NPs. Odontogenic potential of ZnO and ZrO2 particles in combination with WPC was investigated by alkaline phosphatase (ALP) activity and ionized calcium level of supernatant culture media at different time intervals. Data were analyzed using one-way ANOVA and post hoc Tukey tests. Results. All the materials exhibited cell viability over...

Journal of clinical and experimental dentistry, 2017

Presence of voids at root canal wall‒apical seal material interface gives rise to the entrapment ... more Presence of voids at root canal wall‒apical seal material interface gives rise to the entrapment of toxins and microorganisms, which might have a relationship with post treatment disease. The present study was carried out to evaluate the effect of different mixing (manual and ultrasonic) and placement (manual and manual in association with indirect ultrasonic) methods of Calcium-enriched Mixture (CEM) cement on the number and dimensions of voids in the apical plug in simulated apexification models. A total of 80 human maxillary central incisors with mature apices were selected. After simulation of the open apices, the teeth were divided into 4 groups (n=20) based on the mixing and placement techniques of CEM cement: group 1, manual mixing‒manual placement; group 2, manual mixing‒manual placement in association with indirect ultrasonic technique; group 3, ultrasonic mixing‒manual placement; and group 4, ultrasonic mixing‒manual placement in association with indirect ultrasonic techni...

Journal of Clinical and Experimental Dentistry

Background: This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Z... more Background: This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Ze-Ag-Zn) nanoparticles and their effect on the compressive strength of Mineral Trioxide Aggregate (MTA). Material and Methods: Biocompatibility was evaluated by an MTT assay on the pulmonary adenocarcinoma cells with 0.05, 0.1, 0.25, 0.5, 1 and 5 mg/mL concentrations of Ze-Ag-Zn. For compressive strength test, four groups containing 15 stainless-steel cylinders with an internal diameter of 4 and a height of 6 mm were prepared and MTA (groups 1 and 2) or MTA + 2% Ze-Ag-Zn (groups 3 and 4) were placed in the cylinders. The compressive strength was evaluated using a universal testing machine 4 days after mixing in groups 1 and 3, and 21 days after mixing in groups 2 and 4. Results: There was no significant difference between cytotoxicity of different concentrations. The highest (52.22±18.92 MPa) and lowest (19.57±5.76 MPa) compressive strength were observed in MTA group after 21 days and in MTA + 2% Ze-Ag-Zn group after four days, respectively. The effect of time and 2% Ze-Ag-Zn on the compressive strength were significant (P<0.05). Mixing MTA with Ze-Ag-Zn significantly reduced and passage of time from day four to 21 significantly increased the compressive strength. Conclusions: Mixing MTA with 2% Ze-Ag-Zn had an adverse effect on the compressive strength of MTA, but this combination had no cytotoxic effects.

Journal of Clinical and Experimental Dentistry

Background: One of the essential properties of the root canal sealers is the adhesion to root can... more Background: One of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers. Material and Methods: A total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH) 2 , triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the subgroups were obturated with gutta-percha and AH26 or MTA Fillapex sealers. After two weeks incubation, 2-mm-thick middle section of each root was then subjected to push-out testing. Data were analyzed with two-way ANOVA and LSD test. Results: With all the intracanal medicaments, the overall mean of bond strength values were significantly higher with AH26 compared to MTA Fillapex (p<0.05). With the use of MTA Fillapex the maximum and minimum means of bond strength values were recorded with CHX and Metapex and for AH26 were recorded with Ca(OH) 2 and chlorhexidine, respectively.

Journal of Clinical and Experimental Dentistry

Selective properties of MTA with TiO 2 nanoparticles e191

Journal of Clinical and Experimental Dentistry

Background: Proper bond strength to dentin is one of the properties of biomaterials used for ther... more Background: Proper bond strength to dentin is one of the properties of biomaterials used for therapeutic purposes such as repair of furcal perforations. The aim of the present study to evaluate the effects of different powder to liquid ratios of Calcium-enriched mixture (CEM) on the push-out bond strengths in simulated perforations in the furcal area and compare it with Mineral trioxide aggregate (MTA). Material and Methods: Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were prepared in 120 mandibular first molars. Then the samples were randomly assigned to two groups (n=60). MTA and CEM cement were used for the repair of perforations in groups 1 and 2, respectively. Each group was divided into 3 subgroups based on the powder to liquid rations as follows: subgroup 1 (W/P) , 1:2; subgroup 2, 1:3; and subgroup 3, 1:4. After mixing and placing the materials in the perforation area, the samples were placed in closed containers at 37°C and 100% relative humidity for one week. A universal testing machine was used to determine the bond strength values. After recording the standard deviations, data were analyzed with two-way ANOVA. Statistical significance was set at P<0.05. Results: In the MTA and CEM groups the highest push-out bond strength values were recorded in the third (W/P: 1:4) and first (W/P: 1:2) subgroups, respectively. There were significant differences in both groups between the ratios mentioned above and the other ratios (P<0.05). Conclusions: Under the limitations of the present study, an increase in the powder-to-liquid ratio in CEM cement resulted in a decrease in bond strength, contrary to MTA.

Journal of Clinical and Experimental Dentistry

Bond strength of endodontic sealers after Photodynamic therapy and irrigation with nanoparticles ... more Bond strength of endodontic sealers after Photodynamic therapy and irrigation with nanoparticles e1109

Iranian endodontic journal, 2016

The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral triox... more The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral trioxide aggregate (MTA) liquid with volume ratio of 20% on the compressive strength (CS) of MTA in two time periods (4 and 21 days) after mixing. Four groups of steel cylinders (n=15) with an internal diameter of 3 and a height of 6 mm were prepared and MTA (groups 1 and 2) and MTA+PG (80% MTA liquid+20% PG) (groups 3 and 4) were placed in to the cylinders. In groups 1 and 3 the CS was evaluated after 4 days and in groups 2 and 4 after 21 days. Data were calculated using the two-ways ANOVA. The level of significance was set at 0.05. The highest (52.22±18.92 MPa) and lowest (4.5±0.67 MPa) of CS was obtained in 21-day MTA samples and 4-day MTA+PG specimen, respectively. The effect of time and PG were significant on the CS (P<0.05). Mixing MTA with PG significantly reduced the CS; but passing the time from 4 to 21 days significantly increased the CS. Considering the limitations of this study...

Iranian endodontic journal, 2017

The complexity of the root canal system presents a challenge for the practitioner. This systemati... more The complexity of the root canal system presents a challenge for the practitioner. This systematic review evaluated the papers published in the field of root canal anatomy and configuration of the root canal system in permanent maxillary second molars. All articles related to the root morphology and root canal anatomy of the permanent maxillary second molars were collected by suitable keywords from PubMed database. The exhaustive search included all publications from 1981 to December 2015. The articles relevant to the study were evaluated and data was extracted. The author/year of publication, country, number of the evaluated teeth, type of study (method of the evaluation), number of roots and the canals, type of canals and the morphology of the apical foramen was noted. The highest studied populations were in Brazil and United States. A total of 116 related papers were found, which had investigated 11945 teeth in total. Across all the studied populations, the three-rooted anatomy w...

Journal of clinical and experimental dentistry, 2016

Persistent infection of the root canal due to the presence of resistance bacterial species, such ... more Persistent infection of the root canal due to the presence of resistance bacterial species, such as Enterococcus faecalis, has always been one of the most important reasons for endodontic treatment failure. This study investigated the antimicrobial efficacy of 1%, 2.5 % and 5% sodium hypochlorite in eliminating E. faecalis biofilms at different stages of development. In this study 4-, 6- and 10-week-old E. faecalis biofilms were subjected to one of the following approaches: phosphate-buffered saline solution (PBS) or 1%, 2.5% and 5% NaOCl. Dentin chip suspensions were used for colony forming unit (CFU) counting to estimate remaining E. faecalis counts. Statistical comparison of the means was carried out with Kruskal-Wallis test, and pair-wise comparisons were made by Mann-Whitney U test, at a significance level of P<0.05. The results showed that 2.5% and 5% NaOCl completely eliminated E. faecalis biofilms in three stages of biofilm development, whereas 1% NaOCl resulted in 85.73%...